Dave Smith Instruments OB-6 User Manual

Operation Manual

Operation Manual

Version 1.0

March 2016

Dave Smith Instruments LLC

1527 Stockton Street, 3rd Floor

San Francisco, CA 94133

USA

©2016 Dave Smith Instruments LLC

www.davesmithinstruments.com

This device complies with Part 15 of the FCC Rules. Operation is subject to
the following two conditions: (1) This device may not cause harmful inter­ference and (2) this device must accept any interference received, including
interference that may cause undesired operation.

This Class B digital apparatus meets all requirements of the Canadian
Interference-Causing Equipment Regulations.

Cet appareil numerique de la classe B respecte toutes les exigences du
Reglement sur le materiel brouilleur du Canada.

For Technical Support, email: [e-mail]

Table of Contents

A Few Words of Thanks ...............................ix

Getting Started ........................................1

Sound Banks ...........................................2

Selecting Programs ......................................2

Editing Programs ........................................3

Comparing an Edited Program to its Original State ..............3

Creating a Program from Scratch ............................ 4

Live Panel Mode ......................................... 4

Saving a Program ........................................ 5

Canceling Save ..........................................6

Moving to the Next Level ..................................7

Connections ..........................................8

Global Settings ......................................10

Globals - Top Row ......................................11

Globals - Bottom Row .................................... 12

Oscillators ..........................................15

Oscillator Parameters ....................................16

Detune .............................................18

Mixer ...............................................19

Filter ...............................................20

Filter Envelope .......................................22

Changing the Filter Envelope’s Response Curve ...............24

Loudness Envelope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Effects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Effects Parameters ......................................29

Distortion ...........................................33

Low Frequency Oscillators. . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

X-Mod ..............................................36

X-Mod Parameters ......................................37

Arpeggiator Parameters ..................................40

Sequencer ..........................................41

Programming the Sequencer ..............................41

Sequencer Parameters ................................... 43

Portamento ..........................................47

Unison .............................................48

Using Chord Memory ....................................49

Write ...............................................51

Canceling Save .........................................52

Comparing Before You Save ..............................52

Globals .............................................53

Manual .............................................54

Pitch and Mod Wheels ................................55

Pitch Wheel ............................................ 55

Modulation Wheel ....................................... 56

Aftertouch ..........................................56

Exporting Programs and Banks .........................59

Calibrating the OB-6 ..................................60

How and When to Calibrate the Oscillators and Filters ..........60

Calibrating the Pitch and Mod Wheels .......................61

Resetting the Global Parameters ...........................61

Using USB ..........................................62

Appendix A: Alternative Tunings ........................63

Appendix B: Troubleshooting and Support ...............67

Troubleshooting ........................................67

Contacting Technical Support ..............................69

Warranty Repair ........................................70

Appendix C: MIDI Implementation .......................71

MIDI Messages ......................................... 72

NRPN Messages .......................................76

Control NRPN Data .....................................80

Sysex Messages ........................................80

Packed Data Format ....................................83

Credits and Acknowledgements

Sound Design

Cyan Assiter-Clark, Daniel Davis, Peter Dyer, Peter Gorges, Tim Koon, Kurt
Kurasaki, Kevin Lamb, Peter Mahr, Cord Mueller, Drew Neumann, Bob Oxley,
Robert Rich, Matia Simovich, James Terris, Mitch Thomas, Taiho Yamada,
Lorenz Rhode

The DSI Crew

Fabien Cesari, Bob Coover, Carson Day, Chris Hector, Tony Karavidas, Mark Kono,
Justin Labreque, Andy Lambert, Andrew McGowan, Joanne McGowan, Tracy Wadley,
and Mark Wilcox.

Special thanks to Tom Oberheim. Thanks also to Robert Rich for the alternative
tunings content.

A Few Words of Thanks

Thank you for purchasing the OB-6. It’s an awesome-sounding synthesizer and
we’re very proud of it, and I’m very proud to have been able to co-create it with
my old friend, Tom Oberheim.

I’ve known Tom since the late 1970’s when we both shared the heady experience

of creating and selling some of the very  rst polyphonic synthesizers through

our respective companies, Sequential Circuits and Oberheim Electronics. Back
in those days, people were typically in either the Prophet or the Oberheim camp,
and though we were competitors, we were always friendly competitors, and have
remained good friends ever since.

Now, many years later, with the analog synth revival, Tom and I are again
making the instruments that we love. After I reacquired the Sequential brand and
released the Prophet-6 — and saw how much people liked it — the DSI gang and
I thought it would be fun to work with Tom to help bring back his classic SEM­based polyphonic sound in a modern format. So we did. And the result is the very
synth that you’ve just unboxed.

The OB-6 takes the best qualities of Tom’s classic SEM-based synths and adds some
nice touches that the originals never had, such as stereo outputs, velocity and after­touch sensitivity, dual digital effects, a polyphonic step sequencer, an arpeggiator, and
of course, MIDI. The result is a modern classic: Pure vintage analog tone with the
reliability of a state-of-the-art, modern instrument.

Working together to bring you the OB-6 has been a real pleasure. We hope you
enjoy it and make some great music with it!

Cheers,

Getting Started

The OB-6 is a six-voice, polyphonic analog synthesizer with voltage-

controlled oscillators, lters, and ampliers. It was designed to provide

all of the warmth, punch, and presence of a classic, SEM-based Tom
Oberheim synthesizer, with the added convenience and stability of a state­of-the-art, modern instrument.

All of the sound-shaping controls of the OB-6 are accessible on its front
panel, packing a tremendous amount of power and versatility into a
compact, easy-to-use format.

Each of the OB-6’s parameters are explained in later sections of this
manual. But don’t hesitate to dive right in and start turning knobs and
pressing buttons before you begin reading. You can always get back to
where you started, even if you have no idea what you’re doing. So start
exploring and keep your ears and mind open!

USBMIDI INMIDI OUTMIDI THRUPHONES LEFT RIGHT LP FILTER VOLUME SUSTAIN SEQUENCER

MODULATION

X-MOD LFO

AFTERTOUCH

FILTER ENV

AMOUNT

VCO 1 SHAPE 1VCO 1 VCO 2

LFO AMT LOUDNESS

PW 1

FILTR FREQ

FILTR MODE

FILTR FREQ FILTR MODE

WHL RANGE KEY MODE

0

ARPEGG IATOR SEQUENCERCLOCK

OCTAVESVALUE MODETAP TEMPO BPM ON/OFF PLAYRECORD

SINE

SHAPEFREQUENCYVCO 2

SAWTOOTH

REV SAW

SQUARE

RANDOM

INITIAL AMTLFO SYNC

VCO 1 VCO 2 PULSE WIDTH

1 2

AMP FILTR FREQ FILTR MODE

HOLD UNISON

PORTAMENTO

RATE DETUNE GLOBALS

OSCILLATORS MIXER ENVELOPES OUTPUTFILTE R

VCO 1 VCO 2

SYNC

FREQUENCY

FREQUENCY DETUNE

PULSE WIDTH

PULSE WIDTH

BANK

SELECT

1

2

3

LOW FREQ

KEYBOARD

SUB OCTAVE

TENSBANKPR OGRAMTRANSPOSE

SELECT

FREQUENCY

VCO 1 VCO 2

NOTCH

NOISE

LP HP

TransposeIncrementDecrement Master Tune MIDI Channel MIDI Clock Clock Port Param Xmit Param Rcv MIDI Control MIDI SysEx MIDI Out

Local Ctrl Seq Jack Pot Mode Sustain +/- Alt Tuning Vel Response AT Response Stereo/Mono Pgm Dump

10 2 3 4 5 6 7 8 9

ON/OFF EFFECT CLK SYNCTYPE

RESONANCE ATTACK DECAY SUSTAIN RELEASE AM OUNT

ATTACK DECAY SUSTAIN RELEASE AM OUNT

BP

TRACK

HALFFULL

A B

FILTER ENVELOPE

LOUDNESS ENVELOPE

EFFECTS

MIX

1

PAN SPREAD PRGM VO L

VELOCITY

MASTER VOLUME

VELOCITY

WRITE MANUAL

2

PITCH MOD

OB-6 front panel

OB-6 Operation Manual

Getting Started

1

Sound Banks

6 7 8 9

Vel Response AT Response Stereo/Mono Pgm Dump

Param Xmit Param Rcv MIDI Control MIDI SysEx MIDI Out

The OB-6 contains a total of 1000 programs. 500 are permanent and
500 can be overwritten. Banks 0-4 are User Banks that can be overwrit­ten. Banks 5-9 are Factory Banks that are permanent. You can edit the
programs of either bank, but you can only save them to Banks 0-4. As
shipped from the factory, presets 000-499 are identical to 500-999.

TransposeIncrementDecrement Master Tune MIDI Channel MIDI Clock Clock Port

BANK

TENSBANK PROGRA M

Local Ctrl Seq Jack Pot Mode Sustain +/- Alt Tuning

SELECT

Program bank, tens, and number selectors

SELECT

10 2 3 4 5

Selecting Programs

Use the bank, tens, and program selector buttons to select and recall
programs.

To choose a program:

1. Press a program selector button (0-9) to specify the “ones” digit of the
program.

2. Hold down the tens button then press a program selector button (0-9)
to specify the “tens” digit of the program.

3. Hold down the bank button then press a program selector button (0-9)
to specify the “hundreds” bank of the program.

To choose program 123, for example:

1. Hold bank and press 1. Then release the bank button.

2. Hold tens and press 2. Then release the tens button.

3. Press program selector button 3.

Holding down the decrement button and pressing the increment button
advances the program number by 1 value. Conversely, holding down the increment
button and pressing the decrement button decrements the program number by 1 value.
This is especially useful for going between Tens, as you can wrap around to the next
set.

2 Getting Started

Dave Smith Instruments

It’s not always necessary to enter all 3 digits of a program number to
recall it.

For example:

• If the current program is 100 and you want to recall program 101,
simply press “1.”

• If the current program is 100 and you want to recall program 110, hold
down the tens button and press “1.”

• If the current program is 100 and you want to recall program 115, hold
down the

tens button and press “1.” Then release the tens button and

press “5.”

Pressing the globals button three times in a row saves the current program as

the default program that appears when you turn on the OB-6.

Editing Programs

Because all of the sound-shaping controls of the OB-6 appear on its front
panel, editing an existing program is simple: just turn a knob and listen to its
effect. Keep turning knobs and pressing buttons and if you like what you’ve
created, save the program. (See “Saving a Program” on page 5.)

The rotary controls on the front panel are a mixture of “endless” rotary encoders
and potentiometers or “pots.” You can choose between three different modes that
determine how the synth reacts when parameters are edited with a pot. For details,
see “Pot Mode” on page 13.

Comparing an Edited Program to its Original State

When editing a program, it’s often useful to compare its edited state to
its original state to evaluate your edits. Alternatively, before saving a
program to a new location you may want to check the program in the
target location before you overwrite it.

To compare an edited program to a saved version:

1. Edit a program.

2. Press the write button. It starts ashing.

OB-6 Operation Manual

Getting Started

3

3. Press the global button. Both LEDs on the button light up, indicating

compare mode.

4. Play the keyboard to hear the saved version of the sound.

5. To disable the compare function and return to the edited sound, turn off
the global button. Programs can’t be written while in compare mode.

6. If you want to save the edited sound, the write button is still ash­ing and ready to save, so enter a location with the program selector
buttons. The sound is saved.

7. Alternatively, if you want to cancel saving and continue editing, press
the write button. It stops ashing and saving is canceled.

When you’re editing a preset, the OB-6 has a convenient way of indicating the
programmed (saved) value for any knob parameter: Whenever you turn a knob and
reach the saved value of the parameter, an LED dot in the main OB-6 display will
illuminate.

Creating a Program from Scratch

An existing program can be very useful as a jumping off point for new
sounds. But it’s also useful (and educational) to create a new sound from
scratch. The OB-6 makes this easy by providing a “Basic Preset” that
you can quickly recall at any time. This preset is very simple, with a
single oscillator as its basis.

To recall the Basic Preset:

1. Hold down the manual button.

2. Press the write button.

4 Getting Started

Dave Smith Instruments

Live Panel Mode

The OB-6 also features a “live panel” mode in which its sound switches
to the current settings of its knobs and buttons. In other words, the current
preset is ignored and what you see on the front panel is what you hear. This

is a great mode for learning, experimentation, and instant gratication.

To enter live panel mode:

• Press the manual button to toggle it on. Note that you can’t change
programs or banks with manual on.

To return to preset mode:

• Press the manual button again to toggle it off.

MANUAL

Toggling on the manual button enables “live panel” mode

Be aware when entering live panel mode that the current settings of the OB-6
knobs and switches may be such that no sound is produced. This could be because
the Mixer levels are all set to zero, or some other reason. See Appendix B: Trouble-
shooting and Support for a checklist that can help you identify the cause.

Saving a Program

If you’ve created a sound that you like, you’ll probably want to save it.
Saving a program overwrites a previously saved program. Sound design­ers often save many incremental versions of a program as they continue

to rene it. These intermediate versions often make good jumping off

points for new sounds.

To save a program to the same preset location:

1. Press the write button. Its LED begins blinking.

2. Press a program selector button (0-9) to specify the “ones” digit of the
program.

3. The write button LED stops blinking and the program is saved.

OB-6 Operation Manual

Getting Started

5

Be careful when write is enabled. You can change banks and tens without
executing write, but once you press a program selector button (0-9) for the “ones”
digit, the

To save a program to a different bank location:

write command is executed and the program at that location is overwritten.

1. Press the write button. Its LED begins blinking.

2. Hold down the

bank button then press a program selector button to

specify the “hundreds” bank of the program. You can only save to
Banks 0-4.

3. Hold down the

tens button then press a program selector button (0-9)

to specify the “tens” digit of the program.

4. Press a program selector button (0-9) to specify the “ones” digit of the
program.

5. The write button LED stops blinking and the program is saved.

Canceling Save

Sometimes you may want to cancel saving a program before you
commit.

To cancel the Save process before you commit:

• If the write button LED is ashing, press it again. The LED stops ash-
ing and saving is canceled. You can return to editing if you want.

6 Getting Started

Dave Smith Instruments

Comparing Before You Save

Before saving a program to a new location, it’s a good idea to listen to the
program in the target location to make sure you really want to overwrite it.

To evaluate a program before you overwrite it:

1. Get ready to save by pressing the write button. It starts ashing.

2. Press the global button. Both LEDs on the button light up, indicating

compare mode.

3. Use the program buttons to navigate to the sound you want to compare
and play the keyboard to hear the sound.

4. To disable the compare function and go back to the edited sound, turn
off the global button. Programs can’t be written while in compare
mode.

5. If you want to save the edited sound, the write button is still ashing
and ready to save, so enter a location with the program buttons. The
sound is saved.

6. Alternatively, if you want to cancel saving and continue editing, press
the write button. It stops ashing and saving is canceled.

Moving to the Next Level

Before you start exploring the sound creation capabilities of the OB-6
we’d like to point you toward a few things that will help you tailor the
instrument to your needs.

First, check out the Global Settings section of this manual. Read about
Pot Modes and determine which works best for you when you’re editing

sounds. You’ll also nd information about MIDI setup. Read this to more

effectively integrate the OB-6 into your MIDI rig. To get the most out of
the OB-6’s live performance capabilities, read up on using a footswitch
or expression pedal.

And nally, be on the lookout for tips and notes scattered throughout

this manual to gain a better working knowledge of the OB-6. The better
you know it, the more you’ll get out of it. We wish you many hours of
musical exploration!

OB-6 Operation Manual

Getting Started

7

Connections

5 6 7 8 9

1 2 3 4

1. AC Power Connector—Accepts a standard, grounded IEC power

cord. Operates over a range of 100 to 240 volts and 50 to 60 Hz.

2. USB—For bidirectional MIDI communication with a computer. The

OB-6 is a Class Compliant USB device and does not require additional
drivers when used with Mac OS or Windows. See Using USB on page
62 for more information.

3. MIDI In, Out, and Thru—Standard 5-pin MIDI DIN connectors.

4. Footswitch-Sequence—Accepts a momentary, normally open or

normally closed footswitch to turn the sequencer or arpeggiator on and
off. Alternatively, an audio signal connected to this jack can be used to

either control sequencer/arpeggiator playback, or to gate the lter and

loudness envelopes while notes are held. See “Seq Jack” on page 13
for more information about choosing the appropriate mode for these
behaviors.

Audio signals used to drive the arpeggiator/sequencer should not exceed 5

volts peak-to-peak.

5. Footswitch-Sustain—Accepts a momentary, normally open or

normally closed footswitch to control sustain. See Sustain” on page
14 for more information.

8 Connections

Dave Smith Instruments

5 6 7 8 9

6. Expression Pedal-Volume—Accepts a standard expression pedal

that has a variable resistor on a TRS (tip-ring-sleeve) ¼ inch phone plug.
Once connected, you can use the pedal to control volume to add expres­siveness and dynamics to live performance.

7. Expression Pedal- Filter—Accepts a standard expression pedal that

has a variable resistor on a TRS (tip-ring-sleeve) ¼ inch phone plug.
Once connected, you can use the pedal to control the cutoff frequency of

the lter to add expressiveness to live performance.

8. Audio Outputs—Unbalanced, ¼ inch audio outputs. The OB-6

sounds great in stereo, but can be switched to mono if needed. See
“Mono/Stereo” in Global Settings on page 14.

9. Headphones—A ¼ inch stereo headphone jack. Headphone volume is

controlled by the master volume knob on the front panel.

OB-6 Operation Manual

Connections

9

Global Settings

5 6 7 8 9

Vel Response AT Response Stereo/Mono Pgm Dump

Param Xmit Param Rcv MIDI Control MIDI SysEx MIDI Out

Global settings are parameters that affect all programs. These include
settings such as Master Tune, MIDI Channel, MIDI Clock, and others.
Global parameters are printed above the numeric program selector
switches (0 - 9). Use the Globals switch to choose between the two sets.
The red LED indicates that the upper row is active. The yellow LED
indicates that the lower row is active

GLOBALS

The Globals button

Transpose Master Tune MIDI Channel MIDI Clock Clock Port

Local Ctrl Seq Jack Pot Mode Sustain +/- Alt Tuning

10 2 3 4

Globals 0-4

Param Xmit Param Rcv MIDI Control MIDI SysEx MIDI Out

Vel Response AT Response Stereo/Mono Pgm Dump

5 6 7 8 9

Globals 5-9

IncrementDecrement

BANK

SELECT

Use the Bank and Tens buttons to scroll forward and backward, respectively, through parameter settings

10 Global Settings

TENSBANK PROGRAM

SELECT

Dave Smith Instruments

To set a Global parameter:

1. Press the globals button. Pressing it once activates the upper set of
parameters. Pressing it a second time enables the lower set of param­eters.

2. Press the program selector button (0 - 9) that corresponds to the desired
parameter. The parameters are printed above each switch.

3. Use the bank and tens buttons as decrement and increment buttons to
step through available settings.

4. Once you’ve chosen the desired setting, press the

globals button again

to exit.

Globals - Top Row

0. Transpose: -12…12—Master Transpose control, 0 is centered. Steps

in semitones up to one octave up (+12) or down (-12).

1. Master Tune: -50…50—Master Fine Tune control; 0 centered. Steps

in cents as much as a quarter-tone up (+50) or down (-50).

2. MIDI Channel: All, 1…16—Selects which MIDI channel to send and

receive data, 1 to 16.

3. MIDI Clock: Sets the OB-6’s ability to send and receive MIDI clock

messages:

• Off: MIDI Clock is neither sent nor received

• Out: MIDI Clock is sent, but not received

• In: MIDI Clock is received, but not sent

• Slave Thru (i-0): MIDI Clock is received and passed to MIDI Out

• In, No Start/Stop (n55): Receives MIDI Clock but does not respond to

MIDI Start or Stop commands.

all receives on all 16 channels.

When set to in or slave thru, if no MIDI clock is present at the selected input,

the arpeggiator and sequencer will not function.

OB-6 Operation Manual

Global Settings

11

4. Clock Port: MID, USB—Sets the ports, MIDI or USB, by which MIDI

clock signals are received.

5. Param Xmit: Off, CC, NR—Changes to the values of front panel

controls are transmitted via MIDI as Continuous Controllers (CC) or Non­registered Parameter Number (NR). Transmission of parameters can also be

turned off. You could, for example, turn the lter frequency knob on the

OB-6 and have it affect the cutoff frequency of another synthesizer. For a list
of OB-6 CCs and NRPNs, see Appendix D.

NRPNs are the preferred method of parameter transmission, since they cover

the complete range of all parameters, while CCs are limited to a range of 128.

6. Param Rcv: Off, CC, NR—Sets the method by which parameter changes are

received via MIDI. As with transmission, NRPNs are the preferred method.

7. MIDI Control: Off, On—When On, the synth will respond to MIDI

controllers, including Pitch Wheel, Mod Wheel, Pedal, Volume.

8. MIDI Sysex: MID, USB— When set to MIDI (MID) it will receive

and transmit them using the MIDI ports/cables When set to USB it
will receive and transmit them using the USB port/cable. MIDI SysEx
messages are used when sending and receiving a variety of data includ­ing, programs, alternative tunings, system updates, and more.

9. MIDI Out: MID, USB—Sets the port by which MIDI data will be trans-

mitted (MIDI or USB).

Globals - Bottom Row

0. Local Control: Off, On—When on (the default), the keyboard and

front panel controls directly affect the OB-6. When off, the controls are
transmitted via MIDI but do not directly affect the “local” synth (that is,
the OB-6). This is primarily useful for avoiding MIDI data loops that can
occur with some external sequencers.

12 Global Settings

Dave Smith Instruments

1. Seq Jack: NOR, Tri, Gat, T-g (Normal, Trigger, Gate, T-G)—Selects

the mode for signals received on the rear-panel Sequencer jack.

• With normal selected, a footswitch will start sequencer playback.

• With trig selected, an audio signal connected to the sequencer jack will
step the sequencer when the sequencer’s

play button is on.

• With

gate selected, an audio signal connected to the sequencer

jack will trigger and gate the envelopes while you hold a note or
chord. Additionally, turning on the sequencer or arpeggiator will add
sequencer or arpeggiator playback—but controlled by the OB-6’s clock

bpm and value settings and not the audio trigger.

• With

t-g (trigger+gate) selected, an audio signal connected to the

sequencer jack will trigger and gate the envelopes while you hold a

note or chord. Additionally, pressing the sequencer’s play button will
also add synchronized sequencer playback.

For best results when triggering the sequencer with an audio signal, use a loud

signal with a sharp attack/decay and little or no sustain.

2. Pot Mode:

on the front

Rel, Pas, Jup (Relative, Passthru, Jump)—The rotary controls

panel are a mixture of “endless” rotary encoders and potenti-

ometers or “pots.” The pots are identiable by their lined knobs and the

fact that they have about 300° of travel. There are three pot modes to deter­mine how the synth reacts when the programmable parameters are edited.
(Master volume is not programmable, so these modes don’t apply.)

In Relative mode, changes are relative to the stored setting. In Relative mode, the
full value range is not available until either the minimum or maximum value and
the respective lower or upper limit of the pot’s travel is reached.

For example,
the resonance parameter has an internal value range of 0 to 127. Let’s
say the physical position of the resonance pot is the equivalent to a
value of 100. If you switch to a program that has a stored Resonance
setting of 63 and turn the pot all the way up, it will only go to 90. To get

to the maximum value of 127, you rst have to turn down until the value is

at the other extreme and the pot is at the limit of its travel (in this case, 0
and fully counter-clockwise, respectively).

In Passthru mode, turning the pot has no effect until after the edited
value equals the preset value (that is, until the edited value “passes
through” the stored value).

OB-6 Operation Manual

Global Settings

13

Jump mode uses an absolute value based upon the position of the pot
when edited: turn a pot and the value jumps immediately from the stored
value to the edited value.

3. Sustain +/- : Nor, Rev, n-r, r-n (Normally Open, Normally Closed,
Sustain Normally Open/Sequencer Normally Closed, Sustain Normally

Closed/Sequencer Normally Open)—The Sustain pedal polarity param-

eter affects both the sustain pedal and sequencer jack input ports. There
are two types of momentary footswitches, normally open and normally
closed. Either type can be used with the OB-6. Not sure which type
you have? If the behavior of the footswitch is the opposite of what is
expected — that is, down is off and up is on — changing this setting will
correct that.

4. Alt Tuning: Nor, 1…16 (Normal, 1…16)—Selects one of the OB-6’s built-

in tunings. Set to normal, the tuning is standard, chromatic tuning. Choosing
1 through 16 selects an alternative, non-chromatic, non-Western scale that can
be used to emulate ethnic instruments or in other creative ways.

See “Appendix A: Alternative Tunings” on page 63 for a description of
each tuning. Additional tunings can be imported into the OB-6 as a SysEx
message. For more information, see Appendix A.

5. Vel Response: 0-3 (Curve 0, Curve 1, Curve 2, Curve 3)—Sets one of four

velocity curves to adjust the keyboard’s velocity response to your playing style.

6. AT Response: 0-3 (Curve 0, Curve 1, Curve 2, Curve 3)—Sets one of

four pressure curves to adjust the keyboard’s aftertouch response to your
playing style.

7. Stereo/Mono: Ste, Mon (Stereo, Mono)—The OB-6 defaults to stereo

operation. When set to Mono, this parameter defeats all pan settings and
modulation, effectively making each of the outputs a mono output.

8. Pgm Dump: Prg, Ten, Ban, usr, All (Program, Tens, Bank, User
Banks, All)—Transmits the current program, ten programs from the

currently selected bank and tens location, the current bank, all user
banks (0-4), or all banks (both user and factory) in SysEx format via the
selected MIDI port. (See: “MIDI Sysex.”) Dumped programs will load
back into the same bank and program location in memory when received by
the OB-6 via MIDI.

14 Global Settings

Dave Smith Instruments

Oscillators

Oscillators provide the raw building blocks of the OB-6’s sound by
producing waveforms, each of which has its own inherent sound charac­ter based on its harmonic content. The OB-6 has two oscillators, plus a
sub oscillator and a noise generator per voice. Level controls for each of
these are located in the Mixer section.

Oscillator 1 is capable of generating sawtooth, and variable-width pulse
waves. Oscillator 2 generates triangle, sawtooth, and variable-width
pulse waves. These waveshapes are continuously variable and smoothly
transition from one shape to the next as you turn the
provides a variety of “in-between” waveshapes.

shape knob. This

The oscillators on the OB-6 are extremely stable. To emulate the random pitch
drift and oscillator instability of vintage instruments, use the
the

unison button) to dial in as little or as much drift as you like.

detune parameter (next to

OSCILLATORS

VCO 1 VCO 2

FREQUENCY

Oscillators 1 and 2

SYNC

PULSE WIDTH

FREQUENCY DETUNE

PULSE WIDTH

LOW FREQ

KEYBOARD

Oscillator 1 can be hard-synced to Oscillator 2 for complex, harmoni­cally-rich sounds when modulated.

Oscillator 2 features a

detune knob for detuning and thickening sounds,

a low freq switch that allows it to function as an LFO for modulation
purposes, and a keyboard switch that disables keyboard control over its
pitch (useful when used as an LFO, or for drones and other effects).

OB-6 Operation Manual

Oscillators

15

Oscillator Parameters

Frequency: Sets the base oscillator frequency over a 9-octave range from

16 Hz to 8KHz (when used with the Transpose buttons). Adjustment is in
semitones.

The global Master Tune settings affect the pitch of all oscillators. See “Globals -

Top Row” on page 11 for more information.

Detune: Fine tune control with a range of a quartertone up or down. The

12 o’clock position is centered. Steps are in cents (50 cents = 1/2 semi­tone).

Shape: Sawtooth, Pulse (and Triangle on Osc 2) —Used to select the

waveshape generated by the oscillator. Waveshapes are continuously
variable and smoothly transition from one shape to the next as you turn
the shape knob. This provides a variety of “in-between” waveshapes.

Pulse Width: Changes the width of the pulse wave from a square wave

when the pulse width knob is at center position, to a very narrow pulse
wave when the pulse width knob is full left or right.

Applying pulse width modulation using X-mod or the low frequency oscillator
is a great way to add movement and thickness to a sound, especially when creating
pad or string-like sounds.

Sync: Off, On—Turns Oscillator 1 hard sync on. Sync forces Oscillator

1 (the slave) to restart its cycle every time Oscillator 2 (the master) starts
a cycle. This provides a way to create more complex, harmonically rich
shapes from simple waveforms—especially when the frequency of Oscil­lator 1 is set to a different interval than Oscillator 2.

16 Oscillators

Dave Smith Instruments

Oscillator 1

Oscillator 2

Oscillator 1

synced to

Oscillator 2

Oscillator hard sync

Use X-Mod to sweep the pitch of Oscillator 1 when it is synced to generate the
classic, hard-edged sync sound.

Low Frequency: Off, On—Turns Oscillator 2 into a low-frequency

oscillator, essentially providing another LFO source for modulation
using X-Mod. The frequency, detune, shape, and pulse width controls
still apply and will affect the character of any low-frequency modulation
applied using Oscillator 2.

Keyboard: Off, On—When off, the Oscillator 2 ignores the keyboard

and note data received via MIDI and plays at its base frequency setting.
Oscillator 2 pitch can still be affected by modulation from other sources
when in this mode.

OB-6 Operation Manual

Oscillators

17

Detune

Detune (next to the unison button) adds randomized detuning to the
oscillators to emulate the tuning instability of vintage analog oscillators.
This tuning instability is a big part of what made vintage instruments sound
characteristically warm and fat.

Because the OB-6 oscillators are extremely stable, small amounts of

detune can help impart a very vintage tone to what is otherwise a very

stable, modern instrument. detune amount is adjustable from subtle to
wildly out of tune.

unison is enabled, detune detunes the unison voices by a xed

When
amount. Using the pan spread feature, if an odd number of voices is

stacked, one of the voices is placed in the center of the stereo eld with

the other voices spread right and left. The higher the pan spread setting,
the wider the stereo spread in unison.

UNISONDETUNE

The detune knob

The global Master Tune settings affect the pitch of all oscillators. See “Globals -

Top Row” on page 11 for more information.

18 Detune

Dave Smith Instruments

Mixer

The Mixer section is where you set the levels of the various sound gener­ators on the OB-6. These include VCO 1, VCO 2, Sub Octave (Oscillator
1 sub oscillator) and the white noise generator. You must turn up at least
one of these in order to make sound with the OB-6.

Rather than limit the OB-6’s outputs to keep the instrument from clipping, we

allow you to adjust levels at various points in its signal path. This gives you the option
to “overload” things in interesting ways, if you wish to do so. If not, try reducing the
levels of the oscillators in the miXer section, the env amount parameter in the Loudness
Envelope, or the resonance parameter in the lter.

MIXER

VCO 1 VCO 2

SUB OC TAVE

The Mixer

NOISE

VCO 1: Sets the output level of Oscillator 1.

VCO 2: Sets the output level of Oscillator 2.

Sub Octave: Controls the level of a square wave oscillator pitched one

octave below Oscillator 1. Adding a sub octave to sounds such as bass are
a great way to increase their low-register presence.

Noise: Sets the output level of the white noise generator.

OB-6 Operation Manual

Mixer

19

Filter

RESONANCE

TRACK

HALF FULL

BP

FREQUENCY

NOTCH

LP HP

FILTER

The Filter takes the basic, raw sound of the oscillators and noise genera­tor and subtracts frequencies, changing the harmonic content and char­acter of their sound. This change can be varied over time using the Filter
Envelope to produce more dynamic, animated timbres.

The OB-6’s lter is a 2-pole, 12 dB per octave, analog, state-variable lter

with low-pass, notch, high-pass, and band-pass modes.

The lter mode knob sets the lter’s mode of operation. It transitions

smoothly from low-pass to notch to high-pass operation, allowing a
blending of these modes. Band-pass operation is selected with the BP

switch. Each lter mode has its own characteristic sound and function:

• Low-pass: passes frequencies below the cutoff frequency

• Notch: removes frequencies in a notch centered around the cutoff frequency

• High-pass: passes frequencies above the cutoff frequency

• Bandpass: passes a band of frequencies centered around the cutoff frequency

Band-pass mode is selectable only through the bp on/off switch. However, you
can actually smoothly transition between normal and band-pass operation by choosing

norm-bp as a X-Mod destination in the mod matrix.

The OB-6 Filter

20 Filter

Dave Smith Instruments

Frequency: Sets the lter’s cutoff frequency. In Low-Pass mode,

frequencies are reduced from the top down — cutting the high frequen­cies and passing the low, hence the name “low-pass.” In High-Pass mode,
frequencies are reduced from the bottom up — cutting the low frequen­cies and passing the high, hence the name “high-pass.” In Notch mode,
frequencies are removed in a notch centered around the cutoff frequency.

In Bandpass mode, a band of frequencies are passed through the lter

centered around the cutoff frequency — while frequencies on either side
of that band are removed.

Resonance: Emphasizes a narrow band of frequencies around the cutoff

frequency. Unlike low-pass lters on some synthesizers, the OB-6 Low­Pass lter does not self oscillate. This is faithful to the original Oberheim

SEM design.

High levels of resonance can sometimes cause the OB-6 outputs to clip if
its sound generators are also set to high output in the Mixer. Monitor your outputs
carefully to ensure optimal, clean signal levels. If you experience signal clipping, try
reducing the levels of the oscillators in the miXer section, the amount parameter in the
Loudness Envelope, or the resonance parameter in the lter.

Track: off, half, full—Sets the amount of modulation from the keyboard

to the lter’s cutoff frequency. Selecting

half or full means that the

higher the note played on the keyboard, the more the lter opens. This

is useful for adding brightness to a sound as higher notes are played, which
is typically how acoustic instruments behave. If both half and full are off,

keyboard lter tracking is off, meaning that lter frequency is unaffected by

playing higher or lower notes on the keyboard.

OB-6 Operation Manual

Filter

21

Filter Envelope

Attack

Decay

Sustain

Release

Amplitude

Time

The OB-6 lter has a dedicated, four-stage envelope generator. The Filter

Envelope is used to shape the harmonic characteristics of a synthesized

sound by giving you ltering control over its attack, decay, sustain, and

release stages.

This is one of the most important factors in designing a sound. Without

an envelope, the lters would be completely static. They would stay
open or closed by a xed amount that wouldn’t change over the duration

of a sound. That’s not very interesting to listen to and it’s not how instru­ments behave in the real world.

In general, sounds produced by an instrument are brighter at their begin­ning (the attack stage) and grow mellower as they die out (the decay
and release stages). In other words, their harmonic content changes over

time. This is exactly what the lter envelope is designed to emulate.

ENVELOPES

FILTER ENVELOPE

ATTACK DE CAY SUSTAIN RELEASE AMOUNT

VELOCITY

Filter Envelope

A typical 4-stage envelope

22 Filter Envelope

Dave Smith Instruments

Attack: Sets the attack time of the envelope. The higher the setting, the

slower the attack time and the longer it takes for the lter to open from
the level set with the lter frequency knob to the level set by the lter

envelope amount. Percussive sounds typically have sharp (short) attacks.

Decay: Sets the decay time of the envelope. After a sound reaches the

lter frequency set at its attack stage,

decay controls how quickly the

lter then transitions to the cutoff frequency set with the sustain knob.

The higher the setting, the longer the decay. Percussive sounds, such as
synth bass, typically have shorter decays (and a generous amount of low-

pass lter resonance).

Sustain: Sets the lter cutoff frequency for the sustained portion of the

sound. The sound will stay at this lter frequency for as long as a note is

held on the keyboard.

Release: Sets the release time of the envelope. This controls how

quickly the lter closes after a note is released.

Velocity: on, off—When enabled, allows key velocity to inuence lter

frequency. If the amount is set to a positive value in low-pass lter
mode, the harder you play, the more the lter will open and the brighter

the sound will be. Conversely, if the amount is set to a negative value,

the harder you play, the more the lter will close and the less bright the

sound will be. This control makes for more touch-sensitive sounds

Amount: Sets the amount of modulation from the lter envelope to the

lter. Higher amounts more dramatically affect the cutoff frequency. This

control is bipolar. Positive settings produce standard behavior. Negative
settings invert the envelope.

The description of envelope behavior above is true when the amount parameter
is set to a positive value. But since this control is actually bi-polar, it is possible to set
a negative amount of modulation. In this case, the envelopes are inverted and their
behavior changes. The best way to get a feel for the difference is to experiment with
both positive and negative settings of the envelope amount parameter.

The cutoff frequency setting may limit the effect of the envelope on the lter. For
example, in low-pass lter mode , if frequency is at its highest setting, a positive enve-
lope amount will have no effect on the lter since the lter is already completely open.

OB-6 Operation Manual

Filter Envelope

23

Changing the Filter Envelope’s Response Curve

By default, the envelopes of all synthesizers are designed to have certain
type of response curve that is largely dependent on the preference of the
designer. In most cases, this can’t be changed. The current preference is
that the faster or snappier the envelopes, the better.

However, in the case of the OB-6, there is a hidden feature in the X-Mod
section that allows you to modify the responsiveness of the Filter Enve-

lope’s ADSR controls. This opens up a new level of ne adjustment of

these controls that is subtle but powerful. Try it and see.

To adjust the responsiveness of the lter envelope:

1. Select a program — such as a synth brass sound — that has a slightly
soft but bright attack.

2. Repeatedly play a series of notes or chords on the keyboard, so you can
hear the effect of the adjustments as you follow the steps below.

3. In the X-Mod section, enable the filtr freq as the only destination
(disable all other X-Mod destinations such as vco 1, shape 1, etc.).

4. In the X-Mod section, turn the filter env control slightly counterclock-
wise. Try a setting of about 11 o’clock.

5. Continue to play a series of chords and turn the amount knob in the

filter envelope section. Try moving it back and forth between 1

o’clock and 3 o’clock.

6. As you do this, compare different settings of the X-Mod filter env
control, the Filter Envelope amount, and different Attack, Decay,
Sustain, and Release settings on the Filter Envelope.

The interaction of these controls is worth exploring for greater exibility

and control of the Filter Envelope.

24 Filter Envelope

Dave Smith Instruments

Loudness Envelope

Attack

Decay

Sustain

Release

Amplitude

Time

After passing through the lters, a synthesized sound goes into an analog
voltage controlled amplier or VCA, which controls its overall loudness.

The VCA has a dedicated, four-stage envelope generator.

The Loudness Envelope is used to shape the volume characteristics of
a sound over time by giving you control over its attack, decay, sustain,

and release stages. Along with the lter envelope, this is one of the most

important factors in designing a sound.

Without a loudness envelope, the volume of a sound wouldn’t change
over the duration of a note. It would begin immediately, remain at its full
volume for the duration of the note, then end immediately when the note
was released. Again, that’s not very interesting sonically and it’s not typi­cally how instruments behave in the real world.

To give you a real-world example, the main difference between the
sound of the wind and the sound of a snare drum is that they have very
different loudness envelopes. Otherwise, they are essentially both white
noise. Wind has a relatively slow attack, a long sustain, and a long decay
and release. A snare drum has a sharp attack, no sustain, and virtually no
decay or release. But again, they are both fundamentally white noise.

ATTACK D EC AY SUSTAIN RELE ASE AMOUNT

Loudness Envelope

A typical four-stage, ADSR envelope shape

OB-6 Operation Manual

LOUDNESS ENVELOPE

VELOCITY

Loudness Envelope

25

Attack: Sets the attack time of the envelope. The higher the setting, the

slower the attack time and the longer it takes for a sound to reach its full
volume. Pads typically have softer (longer) attacks. Percussive sounds
have sharper (shorter) attacks.

Decay: Sets the decay time of the envelope. After a sound reaches its full

volume at its attack stage,

decay controls how quickly the sound transi-

tions to the level set with the sustain control. The higher the setting, the
longer the decay. Percussive sounds, such as synth bass, typically have
shorter decays.

Sustain: Sets the sustain level of the envelope. The higher the setting,

the louder the sustained portion of the sound will be. The sound will stay
at this level for as long as a note is held on the keyboard.

Release: Sets the release time of the envelope. This controls how

quickly a sound dies out after a note is released.

Amount: Sets the amount of modulation from the Loudness Envelope to

the VCA. In most cases you will probably want to set this fully clockwise
for maximum VCA volume. If you experience signal clipping, try reduc­ing the env amount or the levels of the oscillators in the mixer section.

To recreate the “gated VCA” effect used on certain classic rock anthems,
choose an organ sound, then set the
square wave to amp with an initial amt setting of 100% and hold a few chords.

Velocity: This button enables keyboard velocity to modulate the Loud-

loudness envelope amount to zero, route the LFO

ness Envelope amount. The harder you play, the more the Loudness
Envelope is affected. This makes for more touch-sensitive sounds.

26 Loudness Envelope

Dave Smith Instruments

Effects

The OB-6 effects section allows you to add up to two, 24-bit, 48 kHz digital
effects to any sound. Though the OB-6 sounds great on its own, adding a
touch of reverb or delay can enhance many sounds with a subtle (or not
so subtle) sense of ambience and depth. Other effects such as the chorus
and phaser are useful for adding more conspicuous tonal enhancement as
well as emulating classic instruments such as string ensembles and so on.

While the effects themselves are digital, the main signal path of the OB-6
is analog. The
Effect B, using a true bypass, ensuring a pure analog signal path.

Effects settings are saved individually with each program. Time-based
effects such as the Delays can be synchronized to the arpeggiator, sequencer,
or MIDI clock to produce repeats that occur on the beat.

on/ off switch enables and disables both Effect A and

ON/OFF EFFECT CLK SYNCTYPE

A B

The Effects section

EFFECTS

MIX

2

1

Effects are divided into sets A and B. You can choose a single effect from
each set. Effect A and B are applied one after another, in series. For this
reason, reverb effects are only available as Effect B, since it’s the last
stage in the serial effects chain — where reverb is traditionally applied.
Either effect can also be set to “off.”

OB-6 Operation Manual

Effects

27

Effect A:

• Delay 1 (“bbd”) - vintage bucket-brigade emulation

• Delay 2 (“ddl”) - classic digital delay

• Chorus (“CHO”) - vintage chorus

• Flanger 1 (“FL1” ) vintage anger, high resonance

• Flanger 2 (“FL2”) vintage anger, no feedback

• Phase Shifter 1 (“PH1” ) vintage 6-stage phaser, high resonance

• Phase Shifter 2 (“PH2”) vintage 6-stage phaser, lower resonance

• Phase Shifter 3 (“PH3”) faithful emulation of Tom Oberheim’s
original 6-stage phaser

• Ring Modulator (“Ri n ”) faithful emulation of Tom Oberheim’s
original ring modulator design

Effect B:

• Delay 1 (“bbd”) - vintage bucket-brigade emulation

• Delay 2 (“ddl”) - classic standard digital delay

• Chorus (“CHO”) - vintage chorus

• Flanger 1 (“FL1”) vintage “through-zero” anger, high resonance

• Flanger 2 (“FL2”) vintage “through-zero” anger, no feedback

• Phase Shifter 1 (“PH1” ) vintage 6-stage phaser, high resonance

• Phase Shifter 2 (“PH2”) vintage 6-stage phaser, lower resonance

• Phase Shifter 3 (“PH3”) faithful emulation of Tom Oberheim’s
original 6-stage phaser

• Ring Modulator (“Ri n ”) faithful emulation of Tom Oberheim’s
original ring modulator design

• Reverb 1 (“HAL”) - classic hall emulation

• Reverb 2 (“rOO”) - classic room emulation

• Reverb 3 (“PLA”) - classic plate emulation

• Reverb 4 (“SPr”) - vintage guitar-amp-style spring emulation

28 Effects

Dave Smith Instruments

To use Effects:

1. Press the on/off switch to turn on Effects.

2. Press

effect and choose A or B, depending on which you want to apply

and congure.

3. Turn the

type knob to select an effect. Names are abbreviated. For

instance “bbd” is the bucket-brigade delay. Refer to the list above.

4. Turn the

mix knob to the right to blend in a good amount of the processed

signal. You’ll want to be able to clearly hear the effect when you tweak its
settings. You can dial it down afterward.

5. Use the parameter 1 and parameter 2 knobs to adjust the effect’s param­eters to your taste. See “Effects Parameters” on page 29 for details
on the adjustable parameters on each effect type.

6. Finally, adjust the

mix knob to optimize the amount of the effect. Full

left is completely dry. Full right is completely wet (a 100% processed
signal).

7. Repeat as needed to add a second effect.

Effects Parameters

On/Off: Turns both effects, A and B, on and off. The on/off switch uses a

true bypass, ensuring a pure analog signal path.

Effect: A, B—Selects either effect A or B for editing. Once selected, all

adjustments apply to that effect.

Type: Off, bbd, ddl, CHO, FL1, PH1, PH2, PH3, RNG, HAL, rOO, PLA, SPr—Selects

the effect type.

Mix: 0...127—Sets the balance between the processed (wet) signal

and unprocessed (dry) signal. Full left is completely dry. Full right is
completely wet.

OB-6 Operation Manual

Effects

29

Clock Sync: On, Off—When a delay effect is chosen, this enables syncing

of the timed delay repeats (feedback) to the Arpeggiator, Sequencer, or MIDI
clock. When Sync is on, delay time provides the following values:

Value Delay Time

1 4 beats

2d 3 beats

2 2 beats

4t 1 beat

4d 1 1/2 beat

4 1 beat

8d 3/4 of 1 beat

8 1/2 of 1 beat

8t 1/2 of 1 beat

16d 3/8 of 1 beat

16 1/4 of 1 beat

Maximum delay time is 1 second. The combination of longer synced delay
times with slower tempos can result in delay times that would be greater than 1
second. When that happens, the delay time is divided by 2 until it no longer exceeds
the 1 second limit. For example, if the BPM is set to 60 and Delay Time is set to Half,
the expected delay time would be 2 seconds. The actual delay time will be 1 second
(i.e. 2 seconds divided by 2).

Parameter 1: Variable, depending on the effect—This knob adjusts
parameter 1 for the chosen effect. Each effect has two adjustable param­eters, which differ depending on the effect.

Parameter 2:

Variable, depending on the effect—This knob adjusts

parameter 2 for the chosen effect. Each effect has two adjustable param­eters, which differ depending on the effect.

30 Effects

Dave Smith Instruments

Display Effect Type Parameter 1 Parameter 2

bbd

ddl

cho

fl1

fl2

PH1

PH2

PH3

Rin

HAL

rOO

PLA

SPr

bbd:

This is a vintage bucket-brigade delay emulation. Bucket-brigade

bucket-brigade delay delay time feedback amount

digital delay delay time feedback amount

chorus rate depth

anger rate depth

anger rate depth

phaser 1 rate depth

phaser 2 rate depth

phaser 3 rate depth

ring modulator modulator

frequency

hall reverb time early reections

room reverb time early reections

plate reverb time early reections

spring reverb decay tone

low-note pitch
tracking on/off

delays were originally a type of analog delay characterized by relatively
short delay times and a warmer character than digital delays due to their
loss of treble and clarity in the delayed analog signal. Adjustable param­eters are delay time and feedback amount.

To recreate a classic bucket-brigade time-shifting effect, try adjusting the time

parameter in real time.

ddl: This is a classic digital delay. Adjustable parameters are delay time

and feedback amount.

CHO: This is a vintage chorus emulation. Use it to thicken and add

animation to any sound. Adjustable parameters are rate and depth.

FL1: This is a vintage anger emulation. Use it to add a sweeping reso-

nant effect to a sound. This effect has true through zero anging capabil­ity. Adjustable parameters are rate and depth.

OB-6 Operation Manual

Effects

31

FL2: This is a vintage anger without a feedback path and is designed to

emulate the through zero capability of tape deck anging. Use it to add
a sweeping anged effect to a sound. Adjustable parameters are rate and

depth.

PH1: This is a vintage phaser emulation with high resonance. Use it to

add a deep, sweeping, swirling resonant effect to a sound. Adjustable
parameters are rate and depth.

PH2: This is a vintage phaser emulation with lower resonance. Use it to

add a swirling resonant effect to a sound. Adjustable parameters are rate
and depth.

PH3: This is a faithful emulation of Tom Oberheim’s original phaser

design. Use it to add a swirling resonant effect to a sound. Adjustable
parameters are rate and depth.

rin: This is a faithful emulation of Tom Oberheim’s original ring modula-

tor design. Use it to add a complex harmonic effect to a sound. Adjust­able parameters are the modulation frequency and low note pitch track­ing on/off.

The ring modulator’s mode of operation is determined by the setting of Param­eter 2, (pitch tracking) which can be set to either on or off. With this parameter off, the
ring modulator functions like the original Oberheim unit. In this mode, pitch tracking is
off, and Parameter 1 sets the modulation frequency, which remains the same regard­less of what note you play on the keyboard. With parameter 2 on, the ring modulator
tracks the pitch of the lowest note that you play on the keyboard. In this case the
Parameter 1 sets a ratio between the lowest note that you play and the modulator note

(instead of setting a xed frequency). The modulation frequency will then change as

you change the lowest note that you’re playing, so that the ratio will remain constant
between the note that you play and note of the modulator. If you are only playing one
note at a time, then the ring modulator will modulate with the same ratio as you play
up and down the keyboard.

Set Parameter 2 to the “on” position to get more musical results from the ring

modulator.

32 Effects

Dave Smith Instruments

HAL: This is a Hall reverb. It’s the largest of the available reverbs. Adjust-

EFFECTS

ON/OFF EFFECT TYPE

A B

MIX

Press and hold

for 1 second

Display changes

to “Dist”

Turn Mix knob
to set amount

able parameters are reverb time and early reection amount.

rOO: This is a Room reverb. It’s the second largest of the available reverbs.

Adjustable parameters are reverb time and early reection amount.

PLA: This is a Plate reverb. It emulates a classic reverb plate. Adjustable

parameters are reverb time and early reection amount.

SPr: This is a Spring reverb. It emulates a vintage, guitar-amp-style

reverb. Adjustable parameters are decay and tone.

Distortion

The OB-6 provides an analog distortion effect. This can be used to
add warmth, harmonic complexity, and an aggressive edge to sounds.
The character of the distortion is affected by the harmonic content of a
program. Sounds with more high-end will sound different than sounds
with fewer harmonics.

To add distortion:

1. Press and hold the effect button.

2. Turn the mix knob to set the distortion amount.

3. Release the

Adding the Distortion effect

OB-6 Operation Manual

effect button.

Distortion

33

Low Frequency Oscillator

LFO

The LFO is a special-purpose oscillator that produces a frequency below
the range of human hearing. The LFO is typically used for periodic
modulation such as vibrato (periodic pitch modulation) and tremolo
(periodic amplitude modulation).

The LFO on the OB-6 produces a variety of waveshapes, including sine,
sawtooth, reverse sawtooth, square, and random. Though most often used
for low-frequency modulation, the OB-6 LFO can actually function at speeds
that extend into the audible range for extreme effects.

SHAPEFREQUENCY

INITIAL AMTLFO SYNC

VCO 1 VCO 2 PULSE WIDTH

AMP FILTR FREQ FILTR MODE

The Low-Frequency Oscillator

Sine and Random waves are bipolar. That is, their waveshape is positive for

SINE

SAWTOOTH

REV SAW

SQUARE

RANDOM

1 2

half of their cycle and negative for the other half. In the case of the sine
wave, this makes it possible to generate a natural-sounding vibrato that

goes alternately sharp and at in equal amounts on either side of a center

frequency. Random, also known as “sample and hold,” generates a series
of random values, each held for the duration of one cycle

The square wave, sawtooth, and reverse sawtooth generate only positive
values. In the case of the square wave this makes it possible to generate natural­sounding trills.

34 Low Frequency Oscillator

Dave Smith Instruments

Triangle

Sawtooth

Square RandomSawtooth Reverse

0

LFO waveshapes

The OB-6 has a sixth “hidden” LFO waveshape that you can use as a modula­tion source — noise. To access this, choose random then turn frequency all the way
clockwise. This generates a white noise waveform.

The LFO can be free-running or synced to the arpeggiator, sequencer, or

MIDI clock for tempo-synced effects such as lter sweeps, tremolo, and so on.

Frequency: Sets the frequency of the LFO waveshape routed to the

destination from a slow .022Hz to a fast 500Hz. See also “LFO Sync”
below.

LFO Sync: When on, the LFO synchronizes with the arpeggiator,

sequencer, or MIDI clock. By default, the LFO wave cycle is reset when
you press a key (but is not reset if you press a key while other notes are
held).

Shape: Sine, Sawtooth, Reverse Sawtooth, Square, Random—The

wave shape of the LFO. A sixth waveshape, noise, can be generated by
selecting random and turning the frequency knob all the way to the right.

Initial Amount: Sets the amount of LFO modulation routed to the

selected destinations. Setting an amount here applies the selected modu­lation continuously. If you set this parameter to zero but still select a
modulation destination, modulation is only applied when you use the
Mod Wheel.

VCO 1: Selects the frequency of Oscillator 1 as a modulation destina-

tion. Use a sine wave as a source to create vibrato. Use a square wave to
create trills.

VCO 2: Selects the frequency of Oscillator 2 as a modulation destina-

tion. Use a sine wave as a source to create vibrato. Use a square wave to
create trills.

OB-6 Operation Manual

Low Frequency Oscillator

35

Pulse Width: (Individually selectable for Oscillator 1 and Oscillator 2)

FILTER ENV

VCO 1 SHAPE 1

PW 1

FILTR FREQ FILTR MODE

X-MOD

VCO 2

When Oscillator 1 or 2 are set to square wave, this modulates the pulse
width of the wave. Use a sine wave LFO to create a chorus-like effect
often used to emulate strings.

Amp: Selects the amplitude level as a modulation destination. Use a sine

wave LFO to create a tremolo effect.

Filtr Freq: Selects the lter cutoff frequency as a modulation destination.

Use a sine wave LFO to create an auto-wah effect when in low-pass lter
mode. Modulating the lter at high frequencies can create interesting

timbres.

Filtr Mode: Selects the lter mode as a modulation destination, changing

smoothly between low-pass, notch, and high-pass modes. Modulating the

lter at high frequencies can create interesting timbres.

X-Mod

Although the overall sonic character of the OB-6 is determined by its

analog oscillators and lters, much of its power to make truly unique and

unusual sounds comes from the X-Mod section.

The X-Mod section

36 X-Mod

Dave Smith Instruments

X-Mod modulation sources:

• Filter envelope

• VCO 2 frequency

X-Mod modulation destinations:

• VCO 1 frequency

• VCO 1 waveshape

• VCO 1 pulse width

• Filter cutoff frequency

• Normal to Bandpass lter mode

• Filter mode (Low-Pass, Notch, High-Pass)

You can control how much the source affects the destination by dialing

in a specic modulation amount with the

filter env or vco 2 knobs.

Modulation amount can either be positive or negative.

Use X-Mod to create complex harmonic effects ranging from FM

(frequency modulation) to audio-rate lter modulation and beyond. Many

classic sounds on the original Oberheim OB-series of synthesizers were
created through clever use of X-Mod.

X-Mod Parameters

Filter Env: Selects the amount of modulation from the Filter Envelope

that is applied to a selected destination. Modulation amount can be either
positive or negative.

VCO 2: Selects the amount of modulation from Oscillator 2 that is

applied to a selected destination. Modulation amount can be either posi­tive or negative.

When using vco 2 as a modulation source, the modulation character is
affected by the waveshape currently chosen for Oscillator 2 (triangle, sawtooth, or
square/pulse). Try setting Oscillator 2 to low frequency (using the
further increase modulation possibilities.

OB-6 Operation Manual

low freq switch) to

X-Mod

37

VCO 1: Selects Oscillator 1 frequency as a modulation destination.

Choose vco 2 as a modulation source to produce FM effects with their
characteristic complex harmonics and metallic timbre.

Shape 1: Selects the Oscillator 1 waveshape as a modulation destination.

This can animate the timbre of Oscillator 1 in interesting ways.

PW 1: When Oscillator 1 is set to pulse wave, choosing this as a destina-

tion modulates its pulse width. This will animate the timbre of Oscillator 1
in interesting ways.

Norm - BP: Selects the lter mode as a modulation destination, changing

smoothly between normal lter behavior (low-pass, notch, and high-pass

modes) and bandpass mode.

Filtr Freq: Selects the lter cutoff frequency as a modulation destination.

Use a sine wave LFO to create an auto-wah effect when in low-pass lter
mode. Modulating the lter at high frequencies can create interesting

timbres.

Filtr Mode: Selects the lter mode as a modulation destination, changing

smoothly between low-pass, notch, and high-pass modes. Modulating the

lter at high frequencies can create interesting timbres.

Arpeggiator

The OB-6 has a full-featured Arpeggiator. Turn it on, hold a chord and
the OB-6 will play a pattern based on the individual notes held. Choose
a mode (up, down, random, etc.), an octave range (1, 2, or 3), and a
tempo, then pair it with an appropriately percussive sound, and you’ll be
surprised at the number of creative things you can do.

hold is active, the Arpeggiator is in “relatch” mode, where play-

When
ing a new chord latches to the new chord rather than adding notes to the
existing chord.

38 X-Mod

Dave Smith Instruments

If you enable hold, you can release the notes on the keyboard and the

ARP EGGI ATOR SEQUENCERCLOCK

Arpeggiator will continue to play. In addition, the Arpeggiator features
auto-latching: With hold on, played notes are held on and arpeggiated,
and any additional notes you play are added to the arpeggio—as long as
at least one key is continuously held.

You can sync the Arpeggiator to external MIDI clock, or even an external
audio signal. When the Arpeggiator is playing, the Sequencer is disabled.

OCTAV ESVALUE MODETAP T EMPO BPM ON/OFF PLAYRECORD

1

2

3

The Arpeggiator section

To use the Arpeggiator:

1. Press the Arpeggiator on/off switch to turn it on.

2. Hold down one or more notes on the keyboard. The Arpeggiator plays
them according to the settings you’ve chosen.

3. To latch arpeggiation on (so that you don’t have to continuously hold
down notes) press the

hold button.

4. Adjust settings such as

mode, octave, repeats, bpm and value.

5. To synchronize a delay effect to the Arpeggiator, turn on clock sync in
the Effects section, choose a delay, and adjust its delay time setting as
desired.

An audio signal connected to the rear-panel footswitch - sequence jack can be
used to control arpeggiator (and sequencer) playback. This makes it possible to tempo
sync the arpeggiator to a recorded drum track or other audio source. Audio signals used
to drive the arpeggiator/sequencer should not exceed 5 volts peak-to-peak. See “Seq
Jack” on page 13 for more information about choosing the appropriate mode for these
behaviors.

OB-6 Operation Manual

X-Mod

39

Arpeggiator Parameters

Tap Tempo—Tapping the tap tempo button sets the tempo from 30 to

250 BPM. The LED ashes at the BPM rate you set. Tap the button at

least 4 times to set the tempo.

BPM: 30…250—Sets the tempo for the arpeggiator in BPM (beats per

minute). The tap tempo LED ashes at the BPM rate. When lfo sync is
enabled on the low-frequency oscillator, or clock sync is enabled in the
Effects section, the BPM rate affects the LFO frequency and/or delay effect.
When syncing to an external MIDI clock source, the BPM setting has no effect.

Value—Selects a basic note value relative to the BPM. See the table below:

Name Tempo Timing Division

Half BPM/2 Half note

Qtr BPM Quarter note

8th BPM x 2 Eighth note

8th D BPM x 2 Eighth note, dot

8th S BPM x 2 Eighth note, swing timing

8th T BPM x 3 Eighth note triplets

16th BPM x 4 Sixteenth note

16th S BPM x 4 Sixteenth note, full swing timing

16th T BPM x 6 Sixteenth note triplets

32nd BPM x 8 Thirty-second note

On/Off—

Octave: 1 Octave, 2 Octaves, 3 Octaves—Set to 1 Octave, only the

Turns the Arpeggiator on and off.

keyed notes are arpeggiated. Set to 2 Octaves, the keyed notes and the
notes one octave above them arpeggiate. Set to 3 Octaves, the keyed
notes and the notes one and two octaves above them arpeggiate.

40 X-Mod

Dave Smith Instruments

Mode: Sets the order in which notes play when Arpeggiator is on. See the table.

ARPEGGIATOR SEQ UENCERCLOCK

Arp Mode Behavior

Up Plays from lowest to highest note

Down Plays from highest to lowest note

Up + Down Plays from lowest to highest and back to lowest

Random Plays notes in random order

Assign Plays notes in the order the keys were pressed

Sequencer

The OB-6’s sequencer is similar to a classic step sequencer. It allows you
to create a single sequence of up to 64 steps, including rests and ties, with
up to 6 notes per step. In addition, you can play along with a sequence
(provided there is available polyphony), making it a powerful live perfor­mance tool. When the Sequencer is playing, the Arpeggiator is disabled.

TAP TEMPO

The Sequencer/Arpeggiator

BPM

An audio signal connected to the rear-panel footswitch - sequence jack can
be used to control sequencer playback. This makes it possible to tempo sync the
sequencer (or arpeggiator) to a recorded drum track or other audio source. Audio
signals used to drive the arpeggiator/sequencer should not exceed 5 volts peak-to­peak. See “Seq Jack” on page 13 for more information about choosing the appropri­ate mode for these behaviors.

ON/OFF

OCTAV ESVALUE MODE

RECORD

PLAY

Programming the Sequencer

Though programming the sequencer is simple, you can create sequences that
are rhythmically and melodically complex by combining a repeating phrase
or bass line with chords, ties, and rests. You can play up to 64 steps with up
to 6 notes held simultaneously per step. For most sequences you’ll probably
want to use sounds with a relatively sharp attack and short release.

OB-6 Operation Manual

Sequencer

41

Most factory programs have a sequence associated with them. Recall a
program and press the Sequencer’s play button to hear its associated sequence.

To program a note sequence:

1. Press the record button.

2. Perform the sequence on the keyboard. The display indicates the
current step as you play.

When recording a chord as a step, as long as you continue to hold at least one
note down, you can keep adding notes to the chord/step, and even use the transpose
buttons to extend the keyboard range while doing it.

3. To add a rest as you play, press the tens/increment button for that step,
then continue playing.

4. To add a “tie” that extends the length of a note, continue to hold down
the note(s) and press the tens/increment button repeatedly to extend the
note the number of steps you want.

5. To step back a step in the sequence, press the bank select/decrement
button. This will step back to the previous step so that you can rerecord
it. (Stepping back erases the step.)

6. When you’re done, press play to listen to your sequence.

7. To save the sequence, save the program and they are saved together.
(See “Saving a Program” on page 5.)

If you want to play live along with the sequencer, be sure to leave voices avail-

able. In other words, don’t play 6-note chords for every step in the sequence!

To play a sequence:

1. Press play. The sequence plays back at the current BPM setting.

2. To stop playback, press play again.

Alternatively, you can start and stop sequencer playback using a footswitch
connected to the rear-panel seq jack or using MIDI start/stop messages sent from a
DAW or other MIDI device. See “Seq Jack” on page 13 for more information.

42 Sequencer

Dave Smith Instruments

Use the bpm, value, or tap tempo controls to adjust sequencer playback speed.

To transpose a sequence:

1. Press play. The sequence begins playback.

2. Press and hold record and press a key on the keyboard. “Middle C”
is the reference point. Playing a note above middle C transposes the
sequence higher by that interval. Playing a note below middle C trans­poses the sequence lower by that interval.

Sequencer Parameters

Here are the controls and parameters used when interacting with the sequencer.

Record: On, Off—This switch turns sequencer recording on and off.

Play: On, Off—This switch turns sequencer playback on and off.

BPM: 30…250—Sets the tempo for the Sequencer and Arpeggiator in BPM

(beats per minute). The

sync is turned on, the BPM rate affects the LFO frequency. When syncing to

an external MIDI clock source, the BPM setting has no effect.

Tap Tempo: 30…250—Tap this button at least 4 times to quickly set the

tempo for the Sequencer and Arpeggiator. The LED ashes at the BPM
rate you set.

tap tempo LED ashes at the BPM rate. When lfo

OB-6 Operation Manual

Sequencer

43

Value: Sets the note value for each sequencer/arpeggiator step relative

to the BPM. value works with both internal and external clock sources.
The following table lists the values:

Name Tempo Timing Division

Half BPM/2 Half note

Qtr BPM Quarter note

8th BPM x 2 Eighth note

8th D BPM x 2 Eighth note, dot

8th S BPM x 2 Eighth note, swing timing

8th T BPM x 3 Eighth note triplets

16th BPM x 4 Sixteenth note

16th S BPM x 4 Sixteenth note, full swing timing

16th T BPM x 6 Sixteenth note triplets

32nd BPM x 8 Thirty-second note

44 Sequencer

Dave Smith Instruments

Master Volume/Program Volume

The master output level of the OB-6 is controlled by the front-panel

master volume knob in the output section. In addition, the volume of an

individual program can be set with the prgm vol knob in same section.
This is useful for ensuring that your sounds have roughly the same
volume from program to program. Unison sounds in particular can be
very loud compared to other programs.

OUTPUT

PAN SPREAD PRGM VOL

MASTER VOLUME

The Output section

To set the volume of an individual program:

1. Choose a program.

2. In the

output section, turn the prgm vol knob to set its volume.

3. Save the program. (See “Saving a Program” on page 4.)

MIDI volume can also inuence the overall volume of the OB-6 if you are

controlling it from an external MIDI source.

OB-6 Operation Manual

Sequencer

45

Pan Spread

TRANSPOSE

0

Pan Spread pans audio in the stereo eld individually per voice. Set to

0, all voices are panned to the center. As you turn the pan spread knob
up, the audio in each voice is gradually moved away from the center by
greater amounts. Every other voice goes in a different direction, left or

right. This creates a broader stereo eld while playing..

Transpose

The up and down buttons in the transpose section transpose the keyboard
up or down in octaves. The LED indicates the current keyboard trans­position state. Transposing the keyboard also changes the MIDI note
numbers of the keys so that MIDI notes sent are also transposed. Trans­pose settings are global and are not saved with individual programs.

The Transpose controls

Hold

When hold is on, any notes played will continue to play until hold is
turned off. When used in conjunction with the Arpeggiator, notes are
latched on and replaced by any new note(s) struck. If hold is on and at
least one key continuously held down, any new notes played are added to
the arpeggio.

HOLD

The Hold button

46 Sequencer

Dave Smith Instruments

Portamento

Portamento causes the pitch of a note to glide up or down from the pitch
of the previously played note. Portamento is turned on and off using

portamento switch, but the rate must also be set. If the portamento

the
button is on, but

RATE PORTAMENTO

The Portamento controls

There are four modes that determine how portamento behaves.

Fixed Rate (FR): The time to transition between notes varies with the

interval between the notes; the greater the interval, the longer the transi-

tion time. The portamento rate is xed. This is the default portamento

mode.

Fixed Rate A (FRA): The same as Fixed Rate, but portamento is only

applied when playing legato. That is, portamento only occurs when a
note is held until the next note is played. This effectively allows porta­mento to be turned on and off from the keyboard.

rate amount is set to 0, portamento has no effect.

Fixed Time (FT): Portamento is set to a xed time, regardless of the

interval between notes.

Fixed Time A (FTA): The same as Fixed Time, but portamento only

occurs when playing legato.

To select a portamento mode:

1. Press and hold the portamento switch. The numeric display shows the
currently selected portamento mode.

2. To select a different mode, continue to hold down the portamento
switch then press the bank/decrement and tens/increment switches to
step through the other choices.

3. When nished, release the portamento switch.

OB-6 Operation Manual

Portamento

47

Unison

When unison is on, the OB-6 functions like a monophonic synthesizer in
that only 1 note can be played at a time. However, that one note can be
powered by as many as six voices, depending on how many you choose
to use. With up to 12 oscillators powering a single note (2 oscillators
per voice x 6 voices), you can create some very dense, speaker-rattling
sounds.

If you want to create an ultra heavy synth bass, try using Unison!

Unison gives you control over not only how many voices to stack,
but also the amount of detuning (with the
oscillators, and what note gets priority if you happen to play more than
one note on the keyboard. (This is called the key assign mode or note
priority. See “Key Assign Modes” on page 50 for details.)

detune knob) between the

When Unison is enabled, the

detune knob not only detunes the unison

voices but also spreads them out in the stereo eld. If an odd number of
voices are stacked, one voice is placed in the center of the stereo eld

with the other voices spread right and left. The higher the detune setting,
the wider the stereo spread.

UNISONDETUNE

The Unison button

48 Unison

Dave Smith Instruments

To use Unison:

1. Press and hold the unison switch.

2. With the Unison switch held down, use the

increment switches to choose the number of voices to stack, then

bank/decrement and tens/

release the Unison switch.

3. To detune the oscillators, use the

detune knob.

Using Chord Memory

Unison has another useful feature: chord memory. Instead of assigning
voices to a single note, hold down a chord on the keyboard and press the
Unison switch. The OB-6 memorizes the notes of the chord. Single notes
played on the keyboard will then trigger all notes of the stored chord,
transposing them as you play up or down the keyboard. Try using this
feature to create powerful chord stabs and hits.

If you save a program that uses chord memory, the chord is saved with
the program. “CHD” will then appear as a choice if you step through
voice stacking options using the
buttons while holding down unison.

If low-note priority is chosen in Global settings, the note that you play corre­sponds to the lowest note of the chord voicing. Changing the Key Assign Mode to
high-note priority will make the note that you play correspond to the highest note in
the chord voicing.

banks/decrement and tens/increment

To use chord memory:

1. Hold down a chord on the keyboard (6 notes maximum).

2. Press the

unison switch. The chord voicing is memorized. Play a few

notes to listen to the result.

3. If you save the program, the unison chord memory is saved with it.

To clear chord memory:

1. Turn off Unison.

2. Hold down a single note.

3. Press the

unison button.

4. Save the program again.

OB-6 Operation Manual

Unison

49

Key Assign Modes

UNISON

Key Assign (sometimes called note priority) determines what note has
priority when more than one note is played on the keyboard or via MIDI:

• Low-Note Priority (LO) is most common in vintage synths and is often

used for playing trills by holding a note and repeatedly tapping a lower
note.

• Low Retrigger (LOr) causes the envelopes to be retriggered with each

keystroke.

• High Note (Hi) and High Retrigger (Hir) are similar to the low note

settings, except that the highest note is given priority.

• Last Note (LAS) and Last Retrigger (LAr) give priority to the last note

played.

To choose the Key Assign mode:

1. Press and hold key mode. The numeric display shows the currently
selected mode.

2. To select a different mode, continue to hold down the key mode switch
then press the bank/decrement and tens/increment switches to step
through the other choices.

3. Release the key mode switch when you’re nished.

Key Assign settings are only relevant to Unison mode. They do not affect poly-

phonic playback.

The key mode button

50 Unison

DETUNEKEY MODE

Dave Smith Instruments

Write

TransposeIncrementDecrement Master Tune MIDI Channel MIDI Clock Clock Port Param Xmit Param Rcv MIDI Control MIDI SysEx MIDI Out

The write button saves the currently active program. Saving a program
overwrites a previously saved program.

The OB-6 contains a total of 1000 programs. 500 are permanent and
500 can be overwritten. Banks 0-4 are User Banks that can be overwrit­ten. Banks 5-9 are Factory Banks that are permanent. You can edit the
programs of either bank, but you can only save them to Banks 0-4. As
shipped from the factory, presets 000-499 are identical to 500-999.

WRITE

The Write button

BANK

Program bank, tens, and number selectors

To save a program to the same preset location:

Local Ctrl Seq Jack Pot Mode Sustain +/- Alt Tuning Vel Response AT Response Stereo/Mono Pgm Dump

TENSBANK PROGRAM

SELECT

10 2 3 4 5 6 7 8 9SELECT

1. Press the write button. Its LED begins blinking.

2. Press a program selector button (0-9) to specify the “ones” digit of the program.

3. The write button LED stops blinking and the program is saved.

To save a program to a different bank location:

1. Press the write button. Its LED begins blinking.

2. Hold down the bank button then press a program selector button (0-9)
to specify the “hundreds” bank of the program. You can only save to
Banks 0-4.

3. Hold down the tens button then press a program selector button (0-9)
to specify the “tens” digit of the program.

4. Press a program selector button (0-9) to specify the “ones” digit of the
program.

5. The

write button LED stops blinking and the program is saved.

OB-6 Operation Manual

Write

51

Canceling Save

Sometimes you may want to cancel saving a program before you commit.

To cancel the Save process before you commit:

• If the write button LED is ashing, press it again. The LED stops ash-
ing and saving is canceled. You can return to editing if you want.

Comparing Before You Save

Before writing a program to a new location, it’s a good idea to listen to the
program in the target location to make sure you really want to overwrite it.

To evaluate a program before you overwrite it:

1. Get ready to save by pressing the write button. It starts ashing.

2. Press the global button. Both LEDs on the button light up, indicating

compare mode.

3. Use the program buttons to navigate to the sound you want to compare
and play the keyboard to hear the sound.

4. To disable the compare function and go back to the edited sound, turn off
the global button. Programs can’t be written while in compare mode.

5. If you want to save the edited sound, the write button is still ashing
and ready to save, so enter a location with the program buttons. The
sound is saved.

6. Alternatively, if you want to cancel saving and continue editing, press
the write button. It stops ashing and saving is canceled.

52 Write

Dave Smith Instruments

Globals

Global settings are parameters that affect all programs. These include
settings such as Master Tune, MIDI Channel, MIDI Clock, and others.
Global parameters are printed in two rows the program number switches
(0 - 9). Press the globals button once to access the top row. Press it twice
to access the bottom row. For details on the various Global parameters,
see “Global Settings” on page 10.

GLOBALS

The Globals button

To change a Global setting:

1. Press the globals button. Pressing it once accesses the top row of
Global parameters. Pressing it twice accesses the top row of Global
parameters. The LED indicates which row is active.

2. Press the program selector button that corresponds to the Global
parameter you want to change.

3. Use the bank/decrement and tens/increment buttons to step through
the available settings until you reach the one you want.

4. When nished, press globals again to exit.

Pressing the globals button three times in a row saves the current program as

the default program that appears when you turn on the OB-6.

OB-6 Operation Manual

Globals

53

Manual

The manual switch toggles “live panel” mode on and off. In live panel
mode the OB-6 ignores the currently active preset and reverts to the
current front-panel settings of its knobs and switches. In other words,
what you see on the front panel is what you hear. This is a great mode for

learning, experimentation, and instant gratication.

MANUAL

The Manual button

To enter live panel mode:

• Press the manual button to toggle it on. The OB-6 is now in live panel
mode. What you see on the front panel is what you hear. Note that you
can’t change programs or banks with manual on.

To return to preset mode:

• Press the manual button again to toggle it off. The LED is off. The
current program is what you hear.

Be aware when entering live panel mode that the current settings of the OB-6
knobs and switches may be such that no sound is produced. This could because the
Mixer levels are all set to zero, or some other reason. See Appendix B: Troubleshoot-

ing and Support for a checklist that can help you identify the cause.

54 Manual

Dave Smith Instruments

Pitch and Mod Wheels

The OB-6 has a spring-loaded Pitch wheel and a Mod wheel. You can
use these controls to enhance live performance by bending notes and
adding modulation in real time as you play.

In the same way that guitar players use note bends and vibrato to give
their playing expressiveness and character, these two controls can really

help you dene your sound as a performer and take you beyond just

playing notes on the keyboard.

Pitch Mod

The Pitch and Modulation wheels

Pitch Wheel

You can set a range in semitones for the Pitch wheel, depending on your
playing preference. The range is up to 12 semitones (1 octave). Many
musicians use a range of 2 semitones (a whole step) since this is the bend
range of many acoustic instruments. For guitar whammy bar effects, you
many wish to set a wider range.

To set the pitch bend range:

1. Press and hold the whl range button.

2. With the button still held down, use the bank/decrement and tens/

increment switches to choose the number of semitones (up to 12) for

the pitch bend range, then release the whl range button.

OB-6 Operation Manual

Pitch and Mod Wheels

55

Modulation Wheel

The Mod wheel controls the amount of modulation applied to any destina­tions chosen in the

low-frequency oscillator section. This allows you to

“perform” LFO modulation in real time by moving the Mod wheel. This is a
great way to add expressiveness to a sound or performance.

To choose a modulation destination for the Mod wheel:

1. In the low-frequency oscillator section, choose a modulation desti-
nation as well as a shape and frequency for the LFO. (See “Low
Frequency Oscillators” on page 34 for more details.)

2. To apply modulation only when using the Mod wheel, set the initial

amt knob to zero. (Turning this knob up will apply LFO modulation

continuously — not just when the Mod wheel is used.)

Many programs use the Mod wheel to add vibrato. In this case, vco 1 and vco 2
are enabled as modulation destinations in the low-frequency oscillator section. This
adds vibrato when you push the mod wheel forward. Set the initial amt knob to zero to
apply vibrato only when using the Mod wheel.

Aftertouch

Aftertouch is a performance feature that allows you to add modulation to
a sound by applying additional pressure to a key after the key is already
down. The greater the pressure applied, the more modulation is applied.
The OB-6 provides monophonic (or “channel”) aftertouch, which means
that applying pressure to any key within a chord will apply modulation
to all notes currently held.

The Aftertouch section lets you choose the amount of modulation
applied using aftertouch and which parameters are modulated (oscillator

frequency, lter frequency, etc.). You can set either a positive or negative

amount.

For example, if you select the lter cutoff frequency as destination (

freq), set a positive amount of aftertouch, then press the keys harder, the

filt

lter cutoff frequency will increase, making the lter open wider and the

sound become brighter.

56 Aftertouch

Dave Smith Instruments

Conversely, if you select the lter frequency as destination, set a nega­tive amount of aftertouch, then press the keys harder, the lter cutoff

frequency will be lowered, making the lter close more and the sound

become more muted.

The OB-6 provides four different aftertouch response settings for your conve­nience. The default setting provides a linear response. To choose a different response
curve, use the at response button in the globals section. See page 14 for more
details.

AFTERTOUCH

AMOUNT

VCO 1 VCO 2

LFO AMT LOUDNESS

FILTR FREQ

The Aftertouch controls

FILTR MODE

Amount: Selects the amount of aftertouch applied to a selected destina-

tion. Positive amount settings apply positive amounts of modulation.
Negative amount settings apply negative amounts of modulation.

VCO 1: Selects Oscillator 1 frequency as an aftertouch modulation desti-

nation. With a positive
the Oscillator 1 pitch upward. With a negative

amount setting, pressing the keys harder will shift

amount setting, pressing

the keys harder will shift the Oscillator 1 pitch downward.

OB-6 Operation Manual

Aftertouch

57

VCO 2: Selects Oscillator 2 frequency as an aftertouch modulation desti-

nation. With a positive amount setting, pressing the keys harder will shift
the Oscillator 2 pitch upward. With a negative amount setting, pressing
the keys harder will shift the Oscillator 2 pitch downward.

LFO Amount: Selects the lfo amount parameter as an aftertouch modu-

lation destination. With a positive

amount setting, pressing the keys

harder will increase the amount of LFO modulation to any destina­tion selected in the

amount setting, pressing the keys harder will increase the amount of

low-frequency oscillator section. With a negative

LFO modulation — with the LFO waveform inverted.

Loudness: Selects Amplitude as an aftertouch modulation destination.

With a positive amount setting, pressing the keys harder will increase
the volume of a sound. With a negative

amount setting, pressing the keys

harder will decrease the volume of a sound.

If the Loudness Envelope’s amount is set to full, positive amounts of loudness
aftertouch will have no effect since the VCA is already at its maximum output level.

Filtr Freq: Selects the lter cutoff frequency as a modulation destination.

With a positive amount setting, pressing the keys harder will open the

lter wider and make a sound become brighter. With a negative amount
setting, pressing the keys harder will close the lter more and make a

sound more muted.

Filtr Mode: Selects the Filter Mode as a modulation destination. With a

positive amount setting, pressing the keys harder will move smoothly

between low-pass, notch, and high-pass lter modes.

58 Aftertouch

Dave Smith Instruments

Exporting Programs and Banks

You can use the pgm dump command in the globals section to transmit the
current program, bank, or all banks in SysEx format via the selected
MIDI port. This allows you to save your programs so that you can share
them or archive them.

To export a program or bank as a SysEx le over MIDI:

1. Press the globals button once (this enables the upper set of parameters)
then press program selector 8 to select the midi sysex command.

2. Use the bank/decrement and tens/increment buttons to select the
appropriate MIDI port — MIDI (MID) or USB (usb).

3. Press globals a second time (this enables the lower set of parameters)
then press program selector 8 to select the pgm dump command. The

write button begins ashing.

4. Use the bank/decrement and tens/increment buttons to select the
desired option — program (PRO), tens (ten), bank (ban), user banks
(USR), all (all).

5. Press write. The program or bank is exported.

Dumped programs will load back into the same bank and program location in

memory when received by the OB-6 via MIDI.

OB-6 Operation Manual

Exporting Programs and Banks

59

Calibrating the OB-6

The OB-6 is calibrated at the factory. Controls such as the pitch and mod
wheels shouldn’t require re-calibration. However, because its oscilla-

tors and lters are voltage controlled and can be affected by extremes of

temperature, you may need to use the built-in calibration function to tune
them occasionally.

How and When to Calibrate the Oscillators and Filters

The rst time you use the OB-6, please run its built-in oscillator and
lter calibration procedure. Let it warm up for several minutes and come

to its normal operating temperature before doing so.

Repeat the calibration procedure as needed over the next few days of
use. The OB-6 learns the range of temperatures at your location and will
keep itself in tune over this range.

Later, if you use the OB-6 in a different environment that is measurably
warmer or cooler (on stage, in an air-conditioned studio, and so on) run
the calibration procedure again.

To calibrate the oscillators and lters:

1. Hold down the manual button and press 0.

2. The front panel LEDs and display begin ashing as the OB-6 performs
its auto-calibration procedure. Don’t turn off the power while it’s doing
this.

3. When nished, the front panel controls will return to normal and you
can play the OB-6 again.

60 Calibrating the OB-6

Dave Smith Instruments

Calibrating the Pitch and Mod Wheels

In general, the Pitch and Mod wheels shouldn’t require re-calibration.
However, if you experience what seems like a persistent problem with
either of them, the OB-6 has built-in auto-calibration procedure that you
can use to remedy the problem.

To calibrate the Pitch and Mod wheel’s low position:

1. Rotate and hold both wheels in their low position.

2. Hold down the manual button and press 7.

To calibrate the Pitch wheel’s center position:

• With the Pitch wheel centered, hold down the manual button and press 8.

To calibrate the Pitch and Mod wheel’s high position:

1. Rotate and hold both wheels in their high position.

2. Hold down the manual button and press 9.

Resetting the Global Parameters

If you’re trying to track down a problem, it’s sometimes a good idea to
reset the Global parameters to their defaults. This is a quick way to make
sure that the OB-6 returns to its factory settings.

To reset all Global parameters to their default settings:

• Hold down the global button and press write.

OB-6 Operation Manual

Calibrating the OB-6

61

Using USB

The OB-6’s USB 2.0 port enables bidirectional MIDI communication
with a computer. A MIDI interface and MIDI cables are not neces­sary, just a USB cable. The OB-6 is a Class Compliant USB device.
That means it does not require any additional drivers to be installed to
communicate with a Mac or Windows computer. The OB-6 transmits and
receives MIDI data via USB, but does not transmit audio.

MIDI In and USB should not be used at the same time, as overlapping
messages from different sources may cause the OB-6 to respond unpredictably. MIDI
Out and USB can be used at the same time and transmit the same data.

USB Notes

Under Mac OS X, “OB-6 Keyboard” will appear as a MIDI port when

connected via USB and can be congured using the Mac’s Audio MIDI

Setup utility (typically found in Applications/Utilities).

Under Windows, the rst time the OB-6 is connected via USB, the

“Found new hardware” alert appears and it is automatically installed as
“OB-6 Keyboard.”

In Windows, if you unplug the USB cable and plug it back in while a
program has the OB-6 port open, you may have to resync. That usually
means going to the OB-6 Keyboard Properties — in the Windows
Device Manager under “Sound, video, and game controllers” — and
clicking OK. If OB-6 Keyboard is no longer listed in the Device
Manager, power the OB-6 down and back up again while it is connected
via USB. It should be detected on power up.

62 Using USB

Dave Smith Instruments

Appendix A: Alternative Tunings

By default, the OB-6 is set to standard, chromatic western tuning. Addi­tionally it supports up to 16 additional alternative tunings, which you can
access using the

From the factory, the OB-6 ships with 16 preset alternative tunings
ranging from Equal temperament to Indonesian Gamelan tunings. If you

want, you can replace these with other tunings that you can nd on the

Internet. These must be in SysEx format. You can download them into
the OB-6 using SysEx Librarian for Mac or MIDI-OX for Windows.

Here are descriptions of the default alternative tunings:

Nor (Normal) 12 Tone Equal Temperament (non-erasable)

The default Western tuning, based on the twelfth root of two.

1. Harmonic Series

MIDI notes 36-95 reect harmonics 2 through 60 based on the funda­mental of A = 27.5 Hz. The low C on a standard 5 octave keyboard acts
as the root note (55Hz), and the harmonics play upwards from there. The

remaining keys above and below the 5 octave range are lled with the

same intervals as Carlos’ Harmonic 12 Tone that follows.

alt tuning button in the globals section.

2. Carlos Harmonic Twelve Tone

Wendy Carlos’ twelve note scale based on octave-repeating harmonics.
A = 1/1 (440 Hz). 1/1 17/16 9/8 19/16 5/4 21/16 11/8 3/2 13/8 27/16 7/4
15/8

3. Meantone Temperament

An early tempered tuning, with better thirds than 12ET. Sounds best in
the key of C. Use this to add an authentic touch to performances of early
Baroque music. C=1/1 (260 Hz)

4. 1/4 Tone Equal Temperament

24 notes per octave, equally spaced 24root2 intervals. Mexican composer
Julian Carillo used this for custom-built pianos in the early 20th century.

OB-6 Operation Manual

Appendix A: Alternative Tunings

63

5. 19 Tone Equal Temperament

19 notes per octave (19root2) offering better thirds than 12 ET, a better

overall compromise if you can gure out the keyboard patterns.

6. 31 Tone Equal Temperament

Many people consider 31root2 to offer the best compromise towards just
intonation in an equal temperament, but it can get very tricky to keep
track of the intervals.

7. Pythagorean C

One of the earliest tuning systems known from history, the Pythagorean

scale is constructed from an upward series of pure fths (3/2) transposed

down into a single octave. The tuning works well for monophonic melo-

dies against fth drones, but has a very narrow palate of good chords to

choose from. C=1/1 (261.625 Hz)

1/1 256/243 9/8 32/27 81/64 4/3 729/512 3/2 128/81 27/16 16/9 243/128

8. Just Intonation in A with 7-limit Tritone at D#

A rather vanilla 5-limit small interval JI, except for a single 7/5 tritone
at D#, which offers some nice possibilities for rotating around bluesy
sevenths. A=1/1 (440 Hz) 1/1 16/15 9/8 6/5 5/4 7/5 3/2 8/5 5/3 9/5 15/8

9. 3-5 Lattice in A

A pure 3 and 5-limit tuning which resolves to very symmetrical derived
relationships between notes. A=1/1 (440 Hz)

1/1 16/15 10/9 6/5 5/4 4/3 64/45 3/2 8/5 5/3 16/9 15/8

10. 3-7 Lattice in A

A pure 3 and 7-limit tuning which resolves to very symmetrical derived
relationships between notes. Some of the intervals are very close
together, offering several choices for the same nominal chords. A=1/1
(440 Hz)

1/1 9/8 8/7 7/6 9/7 21/16 4/3 3/2 32/21 12/7 7/4 63/32

64 Appendix A: Alternative Tunings

Dave Smith Instruments

11. Other Music 7-Limit Black Keys in C

Created by the group Other Music for their homemade gamelan, this
offers a wide range of interesting chords and modes. C=1/1 (261.625 Hz)

1/1 15/14 9/8 7/6 5/4 4/3 7/5 3/2 14/9 5/3 7/4 15/8

12. Dan Schmidt Pelog/Slendro

Created for the Berkeley Gamelan group, this tuning ts an Indonesian-

style heptatonic Pelog on the white keys and pentatonic Slendro on the
black keys, with B and Bb acting as 1/1 for their respective modes. Note
that some of the notes will have the same frequency. By tuning the 1/1 to
60 Hz, Dan found a creative way to incorporate the inevitable line hum
into his scale. Bb, B = 1/1 (60 Hz)

1/1 1/1 9/8 7/6 5/4 4/3 11/8 3/2 3/2 7/4 7/4 15/8

13. Yamaha Just Major C

When Yamaha decided to put preset microtunings into their FM synth
product line, they selected this and the following tuning as representative
just intonations. As such, they became the de-facto introduction to JI for
many people. Just Major gives preferential treatment to major thirds on
the sharps, and a good fourth relative to the second. C= 1/1 (261.625)

1/1 16/15 9/8 6/5 5/4 4/3 45/32 3/2 8/5 5/3 16/9 15/8

14. Yamaha Just Minor C

Similar to Yamaha’s preset Just Major, the Just Minor gives preferential

treatment to minor thirds on the sharps, and has a good fth relative to

the second. C= 1/1 (261.625) 1/1 25/24 10/9 6/5 5/4 4/3 45/32 3/2 8/5
5/3 16/9 15/8

OB-6 Operation Manual

Appendix A: Alternative Tunings

65

15. Harry Partch 11-limit 43 Note Just Intonation

One of the pioneers of modern microtonal composition, Partch built

a unique orchestra with this tuning during the rst half of the 20th

century, to perform his own compositions. The large number of intervals
in this very dense scale offers a full vocabulary of expressive chords

and complex key changes. The narrow spacing also allows xed-

pitched instruments like marimbas and organs to perform glissando-like
passages. G = 1/1 (392 Hz, MIDI note 67)

1/1 81/80 33/32 21/20 16/15 12/11 11/10 10/9 9/8 8/7 7/6 32/27 6/5 11/9
5/4 14/11 9/7 21/16 4/3 27/20 11/8 7/5 10/7 16/11 40/27 3/2 32/21 14/9
11/7 8/5 18/11 5/3 27/16 12/7 7/4 16/9 9/5 20/11 11/6 15/8 40/21 64/33
160/81

16. Arabic 12-Tone

A 12-tone approximation of an Arabic scale, which appears in some elec­tronic keyboards designed for use with Arabic music. Not a JI scale, nor
equal tempered. These are the intervals in Cents relative to C:

60 = Cents 0.

61 = Cents +151.

62 = Cents +204.

63 = Cents +294.

64 = Cents +355.

65 = Cents +498.

66 = Cents +649.

67 = Cents +702.

68 = Cents +853.

69 = Cents +906.

70 = Cents +996.

71 = Cents +1057.

72 = Cents +1200

66 Appendix A: Alternative Tunings

Dave Smith Instruments

Appendix B: Troubleshooting
and Support

Troubleshooting

If you’re experiencing problems or unexpected behavior from your
OB-6, here are a few typical scenarios and their solutions:

If the OB-6 isn’t producing sound in live panel mode:

1. Enable live panel mode by pressing the manual button.

2. Initialize a basic program by holding the manual button and pressing
the write button.

3. If the problem is still there, return the instrument to live panel mode
again and check all parameters to make sure they are at non-zero
values. These parameters include:

• VCO 1 & 2 pitch

• VCO 1 & 2 mixer levels

• Program volume

• Master volume

• Set the Loudness Envelope

• Set VCO 1 & 2 to sawtooth

• Set lter cutoff to max

• Check all other parameters by physically changing them.

amount to max. Use a fast envelope with Sustain at max.

If the sequencer or arpeggiator has stopped running:

• Check the MIDI Clock setting in the Globals to ensure the OB-6 is set
to out or, if set to in or slave thru, make sure the OB-6 is receiving
MIDI clock.

If some of the programs sound different than usual:

• Check the Mod Wheel position. The Mod Wheel can do more than
just add vibrato. Also, check the Clock settings in the Global menu to
ensure the OB-6 is set to out or, if set to in or slave thru, make sure
the OB-6 is receiving MIDI clock.

OB-6 Operation Manual

Appendix B: Troubleshooting and Support

67

If there is a ground hum in the audio output:

• USB can cause ground loops, so try to resolve any grounding issues
between the computer and the OB-6. Or use MIDI, which is opto-isolated.

If the OB-6 is behaving erratically.

• This is almost always caused by a MIDI data loop. Make sure that any
MIDI Thru functionality is turned off on the MIDI interface/hardware
or in the MIDI software application. Disconnect all the OB-6’s MIDI
connections—MIDI and USB cables—and see if the problem persists.

You can also monitor the MIDI trafc with MIDI Monitor (Mac OS) or

MIDI-OX (Windows) to see if the OB-6 is being overrun with dupli­cate messages.

If the OB-6 doesn’t seem to respond to its controls:

• Make sure Local Control is on in the Global settings.

If MIDI System Exclusive data is not transmitted/received:

• Make sure that the MIDI SysEx setting in the Global settings is set to

usb or midi depending on which you are using to transmit or receive

MIDI messages.

If the OB-6 plays out of tune:

• Check Transpose and Master Tune parameters in the Global settings. If
they seem correct, you may need to retune the oscillators. See “Cali­brating the Prophet-6” on page 56. If this doesn’t help, recalibrate
the pitch and mod wheels. “Calibrating the Pitch and Mod Wheels” on
page 57.

If the pitch or mod wheel doesn’t go go full range:

• Recalibrate the pitch and mod wheels. See “Calibrating the Pitch and
Mod Wheels” on page 57.

If the lter sounds strange or out of tune:

• You may need to retune the lters. See “Calibrating the Prophet-6” on
page 56.

If the OS Fails to Load Correctly When You Update:

• The OB-6 is equipped with a MIDI bootloader, which will allow you
to reload the OS in the event the you accidentally “brick” your synth
(permanently freeze it) while updating its OS.

68 Appendix B: Troubleshooting and Support

Dave Smith Instruments

To restore your OB-6 if it is frozen.

1. Power on the OB-6 while holding the Write switch to enter bootloader
mode. You’ll see an animation in the Effects Parameter 1 display.

2. Use a MIDI cable (not USB) to transmit the new OS to your synth. You
must use a standard MIDI cable for this. USB MIDI doesn’t work in
bootloader mode.

3. As the OS loads, you will see the main display count backwards from

999. When it gets to 0, another countdown will begin between the main
display and the FX Parameter 1 display. Do not power down until this

countdown has nished. The OB-6 will restart itself when it is done.

Contacting Technical Support

If you are still having a problem with the OB-6, contact Technical
Support at [e-mail]. Please include your
OB-6’s serial number, the version of the operating system (displayed in
the Global screen), and the purchase date.

If you have not already reset the Global parameters and run the calibration

routines (see Troubleshooting), you should do it before contacting Technical Support.

It’s probably the rst thing they’ll ask you to do.

OB-6 Operation Manual

Appendix B: Troubleshooting and Support

69

Warranty Repair

Dave Smith Instruments warrants that the OB-6 will be free from defects
in materials and/or workmanship for 1 year from the date of purchase.
Please register your product online at www.davesmithinstruments.com
to establish the date of purchase. (This is not a requirement for warranty
service, but it will help expedite the process.)

Please contact [e-mail] to determine the best
course of action for getting your OB-6 repaired. For your own protec­tion, as well as ours, please do not return any product to Dave Smith
Instruments without a return authorization (RA) number. To issue an RA
number, Technical Support needs:

• Your name

• Your return address

• Your email address

• A phone number where you can be reached

• Your OB-6’s serial number

• The date of purchase and where purchased

If you need to return your instrument for repair, you are responsible
for getting it to DSI. We highly recommend insuring it and packing in
the original packaging. Damage resulting from shipping a product with

insufcient packaging is not covered by warranty.

70 Appendix B: Troubleshooting and Support

Dave Smith Instruments

Appendix C: MIDI Implementation

The OB-6 receives MIDI data according to the settings you have chosen
in the global settings. In addition, there is interaction between some of
the Program parameters that determine the overall response of OB-6 to
MIDI data. Following are the Global parameters that affect response to
MIDI:

MIDI Channel: All, 1…16—Selects which MIDI channel to send and

receive data, 1 to 16. All receives on all 16 channels.

MIDI Clock: Sets the OB-6’s ability to send and receive MIDI clock

messages:

• Off: MIDI Clock is neither sent nor received

• Out: MIDI Clock is sent, but not received

• In: MIDI Clock is received, but not sent

• Slave Thru (i-0): MIDI Clock is received and passed to MIDI Out

• In, No Start/Stop (n55): Receives MIDI Clock but does not respond to

MIDI Start or Stop command.

When set to in or slave thru, if no MIDI clock is present at the selected input,

the arpeggiator and sequencer will not function.

Clock Port: MID, USB—Sets the port(s), MIDI or USB, by which MIDI

clock signals are received.

Param Xmit: Off, CC, NR—Changes to the values of front panel controls

are transmitted via MIDI as Continuous Controllers (CC) or Non-registered
Parameter Number (NR). Transmission of parameters can also be turned off.

NRPNs are the preferred method of parameter transmission, since they cover

the complete range of all parameters, while CCs are limited to a range of 128.

Param Rcv: Off, CC, NR—Sets the method by which parameter changes are

received via MIDI. As with transmission, NRPNs are the preferred method.

OB-6 Operation Manual

Appendix C: MIDI Implementation

71

MIDI Control: Off, On—When On, the synth will respond to MIDI

controllers, including Pitch Wheel, Mod Wheel, Pedal, Volume.

MIDI Sysex: MID, USB— When set to MIDI (MID) it will receive and

transmit them using the MIDI ports/cables When set to USB it will
receive and transmit them using the USB port/cable. MIDI SysEx
messages are used when sending and receiving a variety of data includ­ing, programs, alternative tunings, system updates, and more.

MIDI Out: MID, USB—Sets the port by which MIDI data will be transmit-

ted (MIDI or USB)..

MIDI Messages

System Real-Time Messages

Status Description

1111 1000 MIDI Timing Clock

Received Channel Messages

Status Second Third Description

1000 nnnn 0kkkkkkk 0vvvvvvv Note Off. Velocity is ignored

1001 nnnn 0kkkkkkk 0vvvvvvv Note On. Note off if vvvvvvv = 0

1010 nnnn 0kkkkkkk 0vvvvvvv Polyphonic Key Pressure

1011 nnnn 0vvvvvvv 0vvvvvvv Control Change; see “Received Controller Messages”

1100 nnnn 0ppppppp Program change, 0-99 for Programs 1-100 within

1101 nnnn 0vvvvvvv Channel Pressure

1110 nnnn 0vvvvvvv 0vvvvvvv Pitch Bend LS Byte then MS Byte

current Bank

Notes: 0kkkkkkk Note number 0 — 127
nnnn Channel number 0 to 15 (MIDI channel 1-16).
Ignored if MIDI channel set to ALL
0vvvvvvv Value

72 Appendix C: MIDI Implementation

Dave Smith Instruments

Received Controller Messages

Status Second Third Description

1011 nnnn 1 0vvvvvvv Mod Wheel: directly assignable controller

1011 nnnn 4 0vvvvvvv Foot Controller: directly assignable controller

1011 nnnn 7 0vvvvvvv Volume: Combined with Master Volume and Voice

1011 nnnn 74 0vvvvvvv Brightness: Added to lter cutoff frequency

1011 nnnn 32 0vvvvvvv Bank Select: 0 - 4 select user banks 0 - 4; 5 - 9 select

1011 nnnn 64 0vvvvvvv Damper pedal: Holds envelopes in Sustain if 0100 0000

1011 nnnn 123 0vvvvvvv All Notes Off: Clear all MIDI notes

1011 nnnn 121 0vvvvvvv Reset All Controllers: Clears all MIDI controllers to 0,

Volume

factory banks 0 - 4; others ignored

or higher

MIDI volume to maximum

See sections below for additional Continuous Controller (CC) and Non­registered Parameter Number (NRPN) messages received.

Transmitted Channel Messages

Status Second Third Description

1000 nnnn 0kkkkkkk 0000000 Note Off.

1001 nnnn 0kkkkkkk 0vvvvvvv Note On.

1011 nnnn 0vvvvvvv 0vvvvvvv Control Change; see “Transmitted Controller Messages”

1100 nnnn 0ppppppp Program change, 0-99 for Programs 00-99 within

1101 nnnn 0vvvvvvv Channel Pressure

1110 nnnn 0vvvvvvv 0vvvvvvv Pitch Bend LS Byte then MS Byte

current Bank

Notes: 0kkkkkkk Note number 0 — 127
nnnn Channel number 0 to 15 (MIDI channel 1-16).
Ignored if MIDI channel set to ALL
0vvvvvvv Value

OB-6 Operation Manual

Appendix C: MIDI Implementation

73

Transmitted Controller Messages

Status Second Third Description

1011 nnnn 0000 0001 0vvvvvvv Mod Wheel

1011 nnnn 0000 0100 0vvvvvvv Foot Controller: When assigned to Pedal 1 or Pedal 2

1011 nnnn 0000 0111 0vvvvvvv Volume: When assigned to Pedal 1 or Pedal 2

1011 nnnn 0100 1010 0vvvvvvv Brightness: When assigned to Pedal 1 or Pedal 2

1011 nnnn 0010 0000 0vvvvvvv Bank Select: 0 - 9

1011 nnnn 0100 0000 0vvvvvvv Damper pedal: Sends 0 if off, 0111 1111 when on

1011 nnnn 0000 0111 0vvvvvvv Volume knob

See sections that follow for additional Continuous Controller (CC) and
Non-registered Parameter Number (NRPN) messages transmitted.

74 Appendix C: MIDI Implementation

Dave Smith Instruments

Additional Continuous Controllers Transmitted/Received

The following table details how MIDI Continuous Controllers (CCs) are
mapped to OB-6 controls. They are transmitted when Param Xmit is set
to CC, and recognized/received when MIDI Rcv Receive is set to CC.

CC# Param

0

Bank Select MSB

1

Mod Wheel

3

BPM

4

Foot Controller

5

Portamento Time

6

Data Enttry MSB

7

MIDI Volume

8

Sub Octave Level

9

Distortion Amount

38

Data Entry LSB

39

Volume LSB

40

VCA Env Amt

41

VCA Env Vel Amt

43

VCA Env Attack

44

VCA Env Decay

45

VCA Env Sustain

46

VCA Env Release

47

Filter Env Amt

50

Filter Env Attack

51

Filter Env Decay

52

Filter Env Sustain

53

Filter Env Release

58

Arp On/Off

59

Arp Mode

60

Arp Octave

62

Arp Clock Division

64

Damper Pedal

65

Portamento On/Off

67

Osc 1 Freq

69

Osc 1 Level

70

Osc 1 Shape

71

Osc 1 Pulse Width

CC# Param

74

Brightness

75

Osc 2 Freq

76

Osc 2 Detune

77

Osc 2 Level

78

Osc 2 Shape

79

Osc 2 Pulse Width

96

Data Increment

97

Data Decrement

98

NRPN Param LSB

99

NRPN Param MSB

100

RPN Param LSB

101

RPN Param MSB

102

Filter Freq

103

Filter Resonance

104

Filter Key Amt

105

Filter Vel On/Off

106

Filter Mode

107

Band Pass On/Off

120

All Sound Off

121

Reset Controllers

122

Local Control On/Off

123

All Notes Off

124

Omni Mode Off

125

Omni Mode On

126

Mono Mode On

127

Poly Mode On

OB-6 Operation Manual

Appendix C: MIDI Implementation

75

NRPN Messages

The Non-Registered Parameter Number (NRPN) MIDI messages are
used to transmit and receive both global and program parameters. They
are transmitted when MIDI Parameter Send is set to NRPN in Global,
and received when MIDI Parameter Receive is set to NRPN in Global.

The messages are handled in standard MIDI format using the NRPN CC
commands in running status byte format. Below is the format used for
transmitting a NRPN parameter.

Transmitted NRPN Messages

Status Description

1011 nnnn Control Change

0110 0011 NRPN parameter number MSB CC

0vvv vvvv Parameter Number MSB

0110 0010 NRPN parameter number LSB CC

0vvv vvvv Parameter Number LSB

0000 0110 NRPN parameter value MSB CC

0vvv vvvv Parameter value MSB

0010 0110 NRPN parameter value LSB CC

0vvv vvvv Parameter value LSB

The parameter number can be found in the two tables below, one for
Global parameters, and the other for Program parameters. The parameter
numbers and the parameter values are broken into two 7-bit bytes for

MIDI transmission; the LSB has the seven least-signicant bits, and the
MSB has the seven most-signicant bits, though in most cases the MSB

will be zero or one, and never more than two.

When receiving an NRPN, all messages do not necessarily need to be
transmitted, since the synth will track the most recent NRPN number,
though it is usually good practice to send the entire message above.

Once an NRPN is selected, the synth will also respond to NRPN Data
Increment and Decrement commands, which some controllers utilize.
Finally, it responds to one RPN (Registered Parameter Number)
command, the RPN/NRPN Reset command, which can be handy for
resetting the currently selected parameter to a known state.

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Received NRPN Messages

Status Second Third Description

1011 nnnn 0110 0011 0vvvvvvv NRPN parameter number MSB CC

1011 nnnn 0110 0010 0vvvvvvv NRPN parameter number LSB CC

1011 nnnn 0000 0110 0vvvvvvv NRPN parameter value MSB CC

1011 nnnn 0010 0110 0vvvvvvv NRPN parameter value LSB CC

1011 nnnn 0110 0000 0xxxxxxx NRPN parameter value Increment

1011 nnnn 0110 0001 0xxxxxxx NRPN parameter value Decrement

1011 nnnn 0010 0101 0111111 RPN parameter number MSB CC - Reset NRPN param-

eter number (when both MSB and LSB received)

1011 nnnn 0010 0100 0111111 RPN parameter number LSB CC - Reset NRPN param-

eter number (when both MSB and LSB received)

Global Parameter Data

The table shows the Global data sent and received on global parameter
dumps, and corresponding NRPN number when sent/received individually.

NRPN Range Description

1024 0-100 Master Fine Tune

1025 0-24 Master Coarse Tune

1026 0-16 MIDI Channel

0 = All

1027 0-3 MIDI Clock Mode

0 = Off
1 = Master
2 = Slave
3 = Slave Thru

1028 0-1 MIDI Clock Port

0 = MIDI Port
1 = USB

1029 0-2 MIDI Param Send*

0 = NRPN
1 = CC
2= Off

1030 0-2 MIDI Param Receive†

0 = NRPN
1 = CC
2= Off

1031 0-1 MIDI Control Enable

0 = Off
1 = On

1032 0-1 MIDI SysEx Enable

0 = Off
1 = On

*Controller received, but not transmitted.
†Controller transmitted, but ignored when received.

NRPN Range Description

1033 0-3 MIDI Out Select

0 = Off
1 = MIDI
2 = USB
3 = MIDI+USB

1035 0-1 Local Control*

0 = Off
1 = On

1037 0-2 Pot Mode

0 = Relative
1= PassThru
2 = Jump

1039 0-3 Seq Jack

0 = normal
1= trigger
2= gate
3= trigger+gate

1040 0-3

Sustain Polarity
0 = normally open
1= normally closed
2= Sustain Normally Open/

Sequencer Normally Closed
3= Sustain Normally Closed/
Sequencer Normally Open

1041 0-3 Velocity Response

1042 0-3 Aftertouch Response

1043 0-1 Mono/Stereo

0 = Stereo
1 = Mono

1044 0-16 Alt Tuning

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77

Program Parameter Data

The following table lists OB-6’s program parameters.

NRPN Value Description

0 0-60 Osc 1 Freq

1 0-1 Osc 1 Sync

2 0-127 Osc 1 Level

3 0-255 Osc 1 Shape

4 0-255 Osc 1 Pulse Width

5 0-60 Osc 2 Freq

6 0-254 Osc 2 Freq Fine

7 0-127 Osc 2 Level

8 0-254 Osc 2 Shape

9 0-255 Osc 2 Pulse Width

10 0-1 Osc 2 Low Freq

11 0-1 Osc 2 Key On/Off

27 0-127 Osc 1 Sub Level

28 0 -3 Portamento Mode

29 0-1 Portamento On/Off

30 0-127 Portamento Rate

31 0-12 Pbend Range

32 0-127 Noise Level

33 0-127 Detune

45 0-164 Filter Freq

46 0-255 Filter Res

47 0-2 Filter Key Amt

48 0-1 Filter Vel On

49 0-1 Filter mode

50 0-1 Filter Normal -

Bandpass

62 0-127 Voice Volume

63 0-127 Pan Spread

64 0-127 Distortion Amt

66 0-127 VCA Env Amt

67 0-127 VCA Env Attack

68 0-127 VCA Env Decay

NRPN Value Description

69 0-127 VCA Env Sustain

70 0-127 VCA Env Release

71 0-1 VCA Env Vel On/Off

77 0-254 Filter Env Amt

78 0-127 Filter Env Attack

79 0-127 Filter Env Decay

80 0-127 Filter Env Sustain

81 0-127 Filter Env Release

88 0-254 LFO Freq

89 0-255 LFO Initial Amt

90 0-4 LFO Shape

91 0-1 LFO Sync

93 0-1 LFO Freq 1

Dest On/Off

94 0-1 LFO Freq 2

Dest On/Off

95 0-1 LFO PW 1, 2

Dest On/Off

96 0-1 LFO Amp Dest

On/Off,

97 0-1 LFO Filter Mode

Dest On/Off

98 0-1 LFO Amp Dest

On/Off

109 0-254 Pressure Amt

110 0-1 Pressure Freq 1

Dest On/Off

111 0-1 Pressure Freq 2

Dest On/Off

112 0-1 Pressure Low-pass

Dest On/Off

113 0-1 Pressure Filter

Mode Dest On/Off

114 0-1 Pressure VCA

Dest On/Off

115 0-1 Pressure LFO Amt

Dest On/Off

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NRPN Value Description

119 0-5 FX 1 Type

120 0-127 FX 1 Mix

121 0-255 FX 1 Param 1

122 0-127 FX 1 Param 2

123 0-1 FX 1 Sync

127 0-9 FX 2 Type

128 0-127 FX 2 Mix

129 0-255 FX 2 Param 1

130 0-127 FX 2 Param 2

131 0-1 FX 2 Sync

135 0-1 FX On/Off

143 0-254 XMod Filter Env Amt

144 0-254 XMod Osc 2 Amt

145 0-1 XMod Freq 1 Dest

On/Off

146 0-1 XMod Shape 1 Dest

On/Off

147 0-1 XMod PW

1 Dest On/Off

148 0-1 XMod Filter Dest

On/Off

149 0-1 XMod Filter Mode

Dest On/Off

150 0-1 XMod Norm-Band-

pass Dest On/Off,

156 0-1 Unison On/Off

157 0-6 Unison Mode

158 0-5 Key Mode

160 0-1 Arp On/Off

161 0-4 Arp mode

162 0-2 Arp Range

163 0-9 Arp Tim Sig

167 30-250 BPM

236-255 32 - 125 Name 0-19

256-319 12-108 Seq Step 1-64

Note 1

320-383 0-127 Seq Step 1-64 Vel 1

384-447 12-108 Seq Step 1-64

Note 2

NRPN Value Description

448-511 0-127 Seq Step 1-64 Vel 2

512-575 12-108 Seq Step 1-64

Note 3

576-639 0-127 Seq Step 1-64 Vel 3

640-703 12-108 Seq Step 1-64

Note 4

704-767 0-127 Seq Step 1-64 Vel 4

768-831 12-108 Seq Step 1-64

Note 5

832-895 0-127 Seq Step 1-64 Vel 5

896-959 12-108 Seq Step 1-64

Note 6

960-1023 0-127 Seq Step 1-64 Vel 6

1024 0-100 Tuning Fine

1025 0-24 Tuning Coarse

1026 0-16 MIDI Channel

1027 0-4 MIDI Clock

1028 0-1 MIDI Clock Port

1029 0-2 MIDI Param Send

1030 0-2 MIDI Param Receive

1031 0-1 MIDI MIDI Control

1032 0-1 MIDI SysEx Control

1033 0-3 MIDI Out

1035 0-1 Local Control

1037 0-2 Pot Mode

1039 0-3 Seq Jack

1040 0-3 Sustain Polarity

1041 0-3 Velocity Response

1042 0-3 At Response

1043 0-1 Stereo Mono

1044 0-16 Alt Tuning

1089 0-127 Seq Transpose

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Appendix C: MIDI Implementation

79

Control NRPN Data

The following table lists the OB-6’s control NRPN data. It is received
and transmitted but not saved as part of a program.

NRPN Value Description

1088 0-1 Seq Play/Stop

16256 0-1 Seq Rec On/Off

Sysex Messages

Universal System Exclusive Message (Device Inquiry)

Status Description

1111 0000 System Exclusive (SysEx)

0111 1110 Non-realtime message

0vvv vvvv If MIDI channel is set to 1 - 16, 0vvvvvvv must match (unless MIDI Channel = ALL); always

0000 0110 Inquiry Message

0000 0001 Inquiry Request

1111 0 111 End of Exclusive (EOX)

The OB-6 responds with:

responds if 0vvvvvvv = 0111 1111.

Status Description

1111 0000 System Exclusive (SysEx)

0111 1110 Non-realtime message

0vvv vvvv If MIDI Channel = ALL, 0vvvvvvv = 0111 1111. Otherwise 0vvvvvvv = Channel Number

0000 0110 Inquiry Message

0000 0010 Inquiry Reply

0000 0001 DSI ID

0010 1101 OB-6 ID (Family LS)

0000 0001 Family MS

0000 0000 Family Member LS

0000 0000 Family Member MS

0jjj nnnn Main Software version: jjj - Minor rev; nnnn - Major rev

1111 0 111 End of Exclusive (EOX)

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Dave Smith Instruments

Request Program Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 1110 OB-6 ID

0000 0101 Request Program Transmit

0000 00vv Bank Number, 0 - 9

0vvv vvvv Program Number, 0 - 99

1111 0 111 End of Exclusive (EOX)

The OB-6 will respond by sending out the Program Data in the format
described below in Program Data Dump.

Request Program Edit Buffer Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 1110 OB-6 ID

0000 0110 Request Program Edit Buffer Transmit

1111 0 111 End of Exclusive (EOX)

The OB-6 will respond by sending out the current Program edit buffer in
the format described below in Program Edit Buffer Data Dump.

Request Global Parameter Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 1110 OB-6 ID

0000 1110 Request Global Parameter Transmit

1111 0 111 End of Exclusive (EOX)

The OB-6 will respond by sending out the current values of Global
Parameters in the format described in Global Parameters Data Dump.

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Appendix C: MIDI Implementation

81

Program Data Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 1110 OB-6 ID

0000 0010 Program Data

0000 00vv Bank Number: 0 - 9

0vvv vvvv Program Number: 0 - 99

0vvv vvvv 1024 bytes expanded to 1171 MIDI bytes in “packed MS bit” format

1111 0 111 End of Exclusive (EOX)

Program Edit Buffer Data Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 1110 OB-6 ID

0000 0011 Edit Buffer Data

0vvv vvvv 1024 bytes expanded to 1171 MIDI bytes in “packed MS bit” format

1111 0 111 End of Exclusive (EOX)

Global Parameters Data Dump

Value Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 1110 OB-6 ID

0000 1111 Main Parameter Data

0vvv vvvv 50 nibbles (LS then MS) for 25 Global parameters

1111 0 111 End of Exclusive (EOX)

The Global Parameters Data Dump is not recognized when received; it is only

transmitted when requested. NRPN messages are used to change Globals.

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Dave Smith Instruments

Packed Data Format

Data is packed in 8 byte “packets”, with the MS bit stripped from 7 param­eter bytes, and packed into an eighth byte, which is sent at the start of the 8
byte packet.

Example:

Input Data Packed MIDI data

1 A7 A6 A5 A4 A3 A2 A1 A0 1 00 G7 F7 E7 D7 C7 B7 A7
2 B7 B6 B5 B4 B3 B2 B1 B0 2 00 A6 A5 A4 A3 A2 A1 A0
3 C7 C6 C5 C4 C3 C2 C1 C0 3 00 B6 B5 B4 B3 B2 B1 B0
4 D7 D6 D5 D4 D3 D2 D1 D0 4 00 C6 C5 C4 C3 C2 C1 C0
5 E7 E6 E5 E4 E3 E2 E1 E0 5 00 D6 D5 D4 D3 D2 D1 D0
6 F7 F6 F5 F4 F3 F2 F1 F0 6 00 E6 E5 E4 E3 E2 E1 E0
7 G7 G6 G5 G4 G3 G2 G1 G0 7 00 F6 F5 F4 F3 F2 F1 F0
8 00 G6 G5 G4 G3 G2 G1 G0

This explains why it takes 1171 MIDI bytes to transmit 1024 Program data bytes.

OB-6 Operation Manual

Appendix C: MIDI Implementation

83

84 Appendix C: MIDI Implementation

Dave Smith Instruments

Dave Smith Instruments LLC

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San Francisco, CA 94133

USA

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