Dave Smith Instruments PROPHET 12 KEYBOARD User Manual

Operation Manual

Operation Manual

Version 1.0

May 2013

Dave Smith Instruments

1527 Stockton Street, 2nd Floor

San Francisco, CA 94133

©2013 Dave Smith Instruments

www.davesmithinstruments.com

Prophet 12 Operation Manual

USA

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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]

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Dave Smith Instruments

Table of Contents

Thank You ..........................................vii

Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

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

Using the Display and “Soft” Controls .........................2

Using Show and Revert Param .............................3

Saving Programs ........................................3

Moving to the Next Level ..................................4

Connections ..........................................6

Global Settings .......................................8

Oscillators ..........................................12

Character ...........................................17

Low-Pass Filter ......................................18

High-Pass Filter ......................................21

Voltage Controlled Amplier ...........................22

Feedback ...........................................24

Delay ...............................................25

Reverb and Modulation-Based Effects .......................26

Low Frequency Oscillators. . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Auxiliary Envelopes ..................................31

Modulation ..........................................32

Using the Assign Mod Buttons .............................32

Prophet 12 Operation Manual

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Distortion ...........................................34

Unison .............................................35

Glide ...............................................36

Hold ................................................37

Arpeggiator .........................................38

Master Volume/Voice Volume ...........................40

Pitch and Modulation Wheels ...........................41

Touch Sliders ........................................42

Layers, Split, and Stack ...............................43

Managing Layers .......................................43

Play List ............................................45

Using USB ..........................................47

Appendix A:

Modulation Sources ..................................49

Appendix B:

Modulation Destinations ...............................50

Appendix C:

Delay Times .........................................52

Appendix D:

MIDI Implementation ..................................57

MIDI Messages ......................................... 58

NRPN Messages .......................................64

Sysex Messages ........................................85

Packed Data Format ..................................... 88

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Dave Smith Instruments

Credits and Acknowledgements

For Sound Design:

Alessandro Cortini

Richard Devine

Rory Dow
Peter Dyer
Tim Koon

Special thanks also to: Ken Eddleman, Jeff Pence, Robert Rich, and Riley Smith

And to the DSI crew: Bob Coover, Carson Day, Chris Hector, Tony Karavidas,

Mark Kono, Andrew McGowan, Joanne McGowan, and Tracy Wadley

Kurt Kurasaki

Jamie Lidell

Tim Mantle (Psalm37)

Phil Peskett

Lorenz Rhode

Matia Simovich

James Terris

Mitch Thomas

Mark Wilcox

Taiho Yamada

Prophet 12 Operation Manual

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vi

Dave Smith Instruments

Thank You

I’ve been designing synthesizers for 35 years now, starting with the Prophet-5
in 1978. Often times over the years, people have asked which instrument is
my favorite. I’ve never been able to answer that question; it’s like picking

your favorite child. The Prophet-5 since it was the rst, and a breakthrough

instrument? The Evolvers with their hybrid analog/digital architecture? The
Prophet ’08, as a modern analog poly synth, a full-featured followup 30 years

after the Prophet-5? The Prophet VS? Wavestation?

The problem is now resolved: the Prophet 12 is my favorite. No question. It
sounds different than my other designs, yet it retains the Prophet vibe. There’s
something magical about the combination of a digital front end followed with

analog lters and electronics per voice. The Prophet 12 has a sound, a soul of its

own, unlike any other instrument. I love it!

I hope you enjoy playing this instrument as much as we enjoyed designing it.
Thanks for the purchase, from the team at DSI!

Cheers,

Prophet 12 Operation Manual

Thank You

vii

viii

Thank You

Dave Smith Instruments

Overview

This is a brief overview of the Prophet 12’s capabilities and its operation.

More in-depth information about specic parameters can be found in the

reference section of the manual. However, don’t let a lack of familiarity
with either the instrument or synthesis prevent you from turning knobs
and pressing buttons. That’s what they’re there for! You won’t break
anything and you can always get back to where you started, even if you
have no idea what you’re doing. Great things can occur with synthesizers
when you don’t quite know what to expect, so start twiddling and keep
your ears—and mind—open.

Getting Started

The Prophet 12 is a twelve-voice, polyphonic synthesizer. That means
up to twelve distinct notes can play simultaneously. The Prophet 12 is a
hybrid synthesizer. That is, it uses a combination of digital and analog
audio electronics to generate its sounds, called programs.

The Prophet 12 contains 792 programs organized into eight banks of 99.
Half the programs are in four Factory banks and the rest are in four User
banks. When a Prophet 12 leaves the factory, the User banks are an exact
copy of the Factory banks. Program 1 in bank 1 of the User banks is the
same as program 1 in bank 1 of the Factory banks, User program 2 is the
same as Factory program 2, and so on. All programs in either the Factory
or User banks can be edited using the front panel controls, but the edits
cannot be saved to the Factory banks, only the User banks. The Factory
banks are read only, permanent.

Choosing programs is simple. Choose User Banks or Factory Banks,
use Bank select to choose bank 1, 2, 3, or 4, and then use the numeric
keypad to enter the program number, 01 through 99. Or use Pgm UP and
Pgm Down to step though consecutive programs.

While auditioning programs, it should become obvious that some
programs are split—two different sounds can be played from different
zones of the keyboard—and some are stacked—one sound is layered on
another. The Prophet 12 is bi-timbral. That is, it can play two different
sounds simultaneously and each of those sounds can be routed to its own
stereo outputs, if desired. Each of the Prophet 12’s program memory
locations is capable of saving and recalling two different programmed

Prophet 12 Operation Manual

Overview

1

sounds, one in layer A and one in layer B. Layers are used to facilitate

The “Soft Keys”

split and stacked programs.

A split program maps the layer A sound to a key zone on the left side of
the split point and the layer B sound to the right. Six voices are allocated
to each key zone.

A stacked program maps both layers A and B to the entire keyboard, with
six voices allocated to each layer. So, when stack a + B is on, the maxi-
mum polyphony is six. (At least two voices play with each keystroke.)
The voice activity LEDs indicate how the voices are being used.

If sPlit a | B or stack a + B are not on, the layer B sound can still be
accessed and edited by pressing eDit layer B. This also provides a
shortcut to switch quickly between two sounds without actually changing
programs.

Using the Display and “Soft” Controls

The Prophet 12’s more performance-oriented parameters are all acces­sible via dedicated knobs and switches on the front panel, but there are
even more parameters available via the OLED display. For example,

there are fteen knobs and switches in the Oscillator section. Editing

any of those controls reveals those parameters and their exact values—
as well as four additional oscillator parameters—in the display. Those
parameters are selected and tweaked using the four soft knobs and soft
keys located above and below the display. The soft knobs are detented

encoders and are great for dialing in specic values.

2

Overview

The “Soft Knobs”

Dave Smith Instruments

Using Show and Revert Param

Editing a program’s parameters causes the value for that parameter to be
displayed. But what if you want to see the value without editing it? show
allows a parameter to be displayed without actually changing it. Simply
press and hold show, and turn a knob or press a switch to display the
current setting. Or press show to turn it on and review multiple param­eter settings before turning show off again.

Tip: Hold show and move the pitch wheel to see the bend range

settings.

At any point while editing a program, turn on comPare to hear the saved,
unedited program. Or, to revert to the saved program, just reload it by
pressing the lit Bank select switch. You can also revert a single param­eter using revert Param. Just press and hold revert Param and turn a
knob to restore it to its saved value.

Saving Programs

Saving an edited program is easy. As mentioned previously, you can
compare the edited program to the saved program at any time using

comPare. Once you’re ready to commit, press write.

A. Write Bank (soft knob 1)—Choose the User Bank (1 through 4) to

which the program will be saved.

B. Write Program (soft knob 2)—Choose the program (1 through 99) to

which the program will be saved.

C. Select Char (soft knob 3)—Highlight a character in the current layer’s

name.

Prophet 12 Operation Manual

Overview

3

D. Edit Char (soft knob 4)—Choose a character.

E. Copy Name A > B (soft key 1)—Copy the layer A name to layer B.

F. Insert Char (soft key 2)—Insert a character before the selected character.

G. Delete Char (soft key 3)—Delete the selected character.

H. Layer A/B (soft key 4)—Switch between the layer A and layer B name.

Saving a program overwrites a previously saved program. While write
is blinking, comPare lets you “audition” the saved program in the bank
and program location you have selected.

Moving to the Next Level

This overview just covers basic operation. The Prophet 12 is a deep

instrument lled with possibility and playing it is a lot more compelling

than reading a manual. But we would like to point you in the direction
of a few things that will help you tailor the instrument to your needs.
In particular, check out the Global Settings section of the manual. Read
about Pot Modes and determine which works best for you. You’ll also

nd information about MIDI setup to more effectively integrate the

Prophet 12 into your rig, as well as information about using a footswitch
and expression pedals. Also, look for the tips and notes scattered
throughout the manual to gain a better working knowledge of the
instrument.

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Overview

Dave Smith Instruments

L

R

L

L

R

L

R

L

R

R

VCA

FEEDBACK LOOP

FDBK TUNE

PAN

HPF

LPF

CHARACTER

PAN

1

DELAY

PAN

2

DELAY

PAN

3

DELAY

PAN

4

DELAY

OSC 1 LEVEL

OSC 1

FEEDBACK LEVEL

OSC 2 LEVEL

OSC 2

DECI AIR GIRTH DRIVE HACK

OSC

OSC 3 LEVEL

OSC 3

Prophet 12 Operation Manual

MIX

OSC 4 LEVEL

OSC 4

SUB OSC LEVEL

SUB OSC

Modulation routing omitted for clarity

PROPHET 12 VOICE ARCHITECTURE

5

USB

Sustain

Pedal 1 Pedal 2 Right Left Right

Connections

100-240 VAC
50-60 Hz
30 Watts

AC Power Inlet—Accepts a standard, grounded IEC power cord. Oper-

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

USB

Sustain

Pedal 1 Pedal 2

MIDI In

MIDI Out MIDI Thru

USB—For bidirectional MIDI communication with a computer. The

Prophet 12 is a Class Compliant USB device and does not require addi­tional drivers when used with Mac OS or Windows. See Using USB on
page 47 for more information.

Sustain—Accepts a momentary, normally open or normally closed

footswitch to control sustain or to turn the arpeggiator on and off. See
“Sustain Footswitch” under Global Settings on page 10 for more
information.

Pedal 1 and Pedal 2—Accept a standard expression pedal that has a

variable resistor on a TRS (tip-ring-sleeve) ¼″ phone plug. For more
information, see “Pedal 1 Function” and “Pedal 2 Function” in Global
Settings on page 10.

Connections

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Dave Smith Instruments

MIDI In

Sustain

Pedal 1 Pedal 2 Right Left Right

USB

MIDI Out MIDI Thru

B Outputs Main / A Outputs

Headphones

Left

B Outputs Main / A Outputs

Right Left Right

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

Left

Headphones

Main/A Outputs and B Outputs—Unbalanced, ¼″ audio outputs. The

Main outputs are a mix of a program’s A and B layers. When plugs
are inserted into the B outputs, only layer A is available from the Main
outputs and layer B is routed to the B outputs. See Layers, Split, and
Stack on page 43 for more information. The Prophet 12 sounds great
in stereo, but can be switched to mono. See “Mono/Stereo” in Global
Settings on page 9.

Headphones—A ¼″ stereo headphone jack.

Prophet 12 Operation Manual

Connections

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Global Settings

Press gloBal to set those parameters, such as Master Tune and MIDI
Channel, which affect all programs globally.

1. Master Coarse Tune: -12…+12—Master Transpose control, 0 is

centered. Steps in semitones as much as one octave up (+12) or down
(-12).

2. Master Fine Tune: -50…+50—Master Fine Tune control; 0 centered.

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

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

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

4. MIDI Clock Mode: See table—Sets the Prophet 12’s ability to send

and receive MIDI clock messages.

Display MIDI Clock Setting

Off MIDI Clock is neither sent nor received.

Master MIDI Clock is sent, but not received.

Slave MIDI Clock is received, but not sent.

Slave Thru MIDI Clock is received and passed to MIDI Out.

Note: In Slave and Slave Thru modes, if no MIDI clock is present at

the selected input, the arpeggiator will not function.

5. MIDI Clock Cable: MIDI Port, USB—Sets the port, MIDI or USB, by

which MIDI clocks are received.

5. MIDI Param Send: Off, CC NRPN—Changes to the values of front

panel controls are transmitted via MIDI as Non-registered Parameter
Number (NRPN) controllers or as Continuous Controllers (CC). Trans­mission of parameters can also be turned off. See MIDI Implementation
on page 55 for details.

Note: 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.

Global Settings

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Dave Smith Instruments

6. MIDI Param Receive: Off, CC NRPN—Sets the method by which

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

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

MIDI controllers, including Pitch Wheel, Mod Wheel, Pedal, Breath,
Volume, and Expression.

8. MIDI Sysex Enable: Off, On—When On, the synth will respond to

received MIDI SysEx messages, and will transmit them, when prompted,
to the MIDI Out. See Sysex Messages on page 82 for details.

9. MIDI Sysex Cable: None, MIDI Port, USB—Sets the port, MIDI or

USB, by which System Exclusive data will be transmitted and received.

10. MIDI Out Select: Off, MIDI, USB, MIDI+USB—Sets the port by which

MIDI data will be transmitted.

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

front panel controls directly affect the Prophet 12. When off, the controls
are transmitted via MIDI but do not directly affect the “local” synth (that
is, the Prophet 12). This is primarily useful for avoiding MIDI data loops
that can occur with some external sequencers.

12. Mono/Stereo: Stereo, Mono—The Prophet 12 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.

13. Pot Mode: Relative, Passthru, Jump—The rotary controls on the

Prophet 12’s front panel are a mixture of “endless” rotary encoders and

potentiometers 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.)

When set to Relative, 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.

Prophet 12 Operation Manual

Global Settings

9

For example, the Resonance parameter has a value range of 0 to 127.
Let’s say the physical position of the Resonance pot is the equivalent of
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).

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.

14. Sustain Footswitch: Normally Open, Normally Closed—There are

two types of momentary footswitches, normally open and normally
closed. Either type can be used with the Prophet 12’s Sustain switch
input. Not sure which type you have? If the footswitch’s behavior is the
opposite of what’s expected—that is, down is off and up is on—changing
this setting will correct that.

16. Sustain Pedal Function: Sustain, Arp On/Off—The footswitch can

be used for sustain or to turn arpeggiator hold on and off.

15. Pedal 1 Function: Breath Control, Foot Controller, Expression,
Master Volume, Lowpass Filter: Full Range, Lowpass Filter: Half

Range—Sets the function/destination for the Pedal 1 input. An expres-

sion pedal can be routed to any destination using the modulation matrix.
See Modulation on page 32 for more information.

16. Pedal 2 Function: Breath Control, Foot Controller, Expression,
Master Volume, Lowpass Filter: Full Range, Lowpass Filter: Half

Range—Sets the function/destination for the Pedal 2 input. . An expres-

sion pedal can be routed to any destination using the modulation matrix.
See Modulation on page 32 for more information.

17. Aftertouch Enable: Off, On—When on, the Prophet 12 will receive

and transmit aftertouch data via MIDI.

Global Settings

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Dave Smith Instruments

18. Aftertouch Curve: Curve 1, Curve 2, Curve 3, Curve 4—Sets one

of four pressure curves for the keyboard to adjust the aftertouch to your
playing style.

19. Velocity Curve: Curve 1, Curve 2, Curve 3, Curve 4—Sets one of the

four velocity curves for the keyboard to adjust the velocity response to
your playing style.

20. Basic Patch—Press Write Now (soft key 1) to load a basic, template

program into the edit buffer. Use write to permanently save any changes
to memory.

21. Calibrate Sliders—Press Start Cal (soft key 1) and follow the

onscreen instructions to calibrate the sliders.

22. Calibrate Wheels—Press Start Cal (soft key 1) and follow the

onscreen instructions to calibrate the wheels.

23. Autotune Filters—Press Start Tuning (soft key 1) and follow the

onscreen instructions to tune the low- and high-pass lters.

Note: The sliders, wheels, and lters are calibrated at the factory

and under normal circumstances should not require re-calibration or
re-tuning.

24. Reset Globals—Sets the global parameters to the factory default

settings.

25. Dump Current Program—Transmits the current program in SysEx

format via the selected MIDI port. (See “9. MIDI Sysex Cable.”)
Dumped programs will load back into the same bank and program loca­tion in memory when received by the Prophet 12 via MIDI.

26. Dump Current Bank—Transmits the current bank in SysEx format

via the selected MIDI port. (See “9. MIDI Sysex Cable.”) Dumped banks
will load back into the same bank location in memory when received by
the Prophet 12 via MIDI.

27. Dump All User Banks—Transmits all four User Banks and the play

lists in SysEx format via the selected MIDI port. (See “9. MIDI Sysex
Cable.”) Dumped banks will load back into the same bank location in
memory when received by the Prophet 12 via MIDI.

Prophet 12 Operation Manual

Global Settings

11

Oscillators

The Prophet 12 has four oscillators for each of its twelve voices. The
oscillators are capable of generating the “classic” analog wave shapes—
sine, triangle, sawtooth, square—as well as more complex shapes and
different types of noise.

Use the four oscillator buttons to select an oscillator for editing. The
mysterious ring that connects the buttons is not a life preserver. It’s a
graphic representation showing which oscillator affects another when
the Sync, FM (frequency modulation), or AM (amplitude modulation)
parameters are used. Oscillator 2 affects oscillator 1, oscillator 3 affects
oscillator 2, and so on. For information about what the Sync, FM, and
AM parameters do, see the relevant items later in this section.

Tip: Press and briey hold any of the oscillator select buttons to light

all four buttons and edit a parameter on all oscillators simultaneously.
Or use the soft knobs to edit the same parameter for each oscillator
individually. Press any oscillator button to exit.

Shape/Noise: Off, Sawtooth, Pulse, Triangle, Sine, Tines, Mellow,
Church, Muted, Nasal, Boing, Gothic, Ahhh, Shrill, Ohhhh, Buzzzz, Meh,

Red Noise, White Noise, Violet Noise—Used to select the wave shape or

type of noise generated by the selected oscillator. Wave shapes include
four typical analog synthesizer waves as well as twelve more complex
wavetable sounds. There are also three types of noise: red, white, and
violet.

Shape Mod/Pulse Width: -64…0…63—Causes the wave shape to be

altered. How it changes depends upon the selected shape. A setting of 0
is the default, unaffected shape.

When Sawtooth is the selected shape, shaPe moD/PUlse wiDth controls
the symmetry of the wave, similar to pulse width on the Pulse wave.

shaPe moD/PUlse wiDth affeccts the pulse width or duty cycle of the
Pulse wave.

-64 63

Oscillators

12

0

Pulse Width

Dave Smith Instruments

When Triangle is the selected shape, the width of the wave is changed,
similar to Pulse and Sawtooth, adding harmonics and getting more thin
sounding when turned in either direction from 0.

With Sine as the selected shape, values less than 0 gradually add another
sine an octave higher than the base pitch. Values greater than 0 cause
the sine wave to gradually be clipped, adding harmonics and sounding
somewhat distorted.

For the 12 wavetable shapes, shaPe moD/PUlse wiDth crossfades
between the selected shape and the Wave Left and Wave Right selec­tions. Let’s say, for example, that the selected wave shape is Mellow,
Wave Left is set to Tines, and Wave Right is set to Nasal. A shaPe moD/
PUlse wiDth setting of -64 will be the Tines wave, 0 will be Mellow, and
+63 will be Nasal. Values between -64 and 0 will be a mix of Tines and
Mellow; values between 0 and +63 will be a mix of Mellow and Nasal.
An extremely broad variety of hybrid wave shapes can be created by
mixing two of the wavetable shapes. And, of course, shaPe moD/PUlse
wiDth is a modulation destination, so an LFO or other modulation source
can be routed to it. Note that the algorithm used to mix the waves is not
simply a mix. If all three are set to the same wave, there will still be a
noticeable difference in the sound as Shape Mod changes.

shaPe moD/PUlse wiDth also works when noise is the selected shape.
With a Shape Mod value of 0, the displayed noise type is what is heard.
Values less than 0 gradually cause it to change to a second noise type.
Values greater than 64 cause it to change to a third noise type. The left

and right noise sources are xed. Try it. It’s much easier to hear than to

explain! The display also provides a visual indication of the change.

Wave Left, Wave Right—Sets the wavetable shapes used in conjunc-

tion with the shaPe moD/PUlse wiDth parameter. Wave Left and Wave
Right are only active when one of the twelve wavetables is selected as
the primary oscillator shape. See “Shape Mod/Pulse Width” for more
information.

Pitch: C 0…C 10—Sets the base oscillator frequency over a 10-octave

range, from 8 Hz to 8KHz, stepping in semitones. C3 is middle C, the

rst octave is 0 (C0, C#0, etc.), the second octave is 1 (C1, C#1, etc.),

and so on.

Prophet 12 Operation Manual

Oscillators

13

Note: The global Master Tune settings affect the pitch of all oscilla-

tors. See Global Settings on page 8 for more information.

Fine: -50…+50—Fine tune control with a range of a quartertone up or

down. Zero is centered. Steps are in cents (50 cents = 1/2 semitone).

Key Follow: Off, On—When Key Follow is on, the oscillator tracks the

keyboard or note data received via MIDI. When off, the oscillator plays
at its base frequency setting, though the pitch may be affected by modu­lation from other sources.

Wave Reset: Off, On—When Wave Reset is off, the Prophet 12’s oscil-

lators are free running, which is typically how analog synths behave.
That is, the oscillators are running whether a note is being gated on or

not. When the amplier envelope is set for a fast attack, this can cause a

soft, but detectable, pop or click at the beginning of a note because the
note might be gated on at a point in the wave’s cycle other than a zero

crossing. The rst cycle to play might be truncated. For some sounds,

like monophonic basses, this may actually be desirable. It adds a bit
of randomness to the attack that can make it sound, for lack of a better
word, more organic. When Wave Reset is on, the wave is always reset to
zero—the start of its cycle—when a note is gated on.

Sync: Off, On—Turns oscillator hard sync on. Sync utilizes pairs of

oscillators to force one oscillator (the slave) to restart its cycle every time
the other oscillator (the master) starts a cycle. This provides a way to
create more complex, harmonically rich shapes from simple waveforms.

Oscillator 1

Oscillator 2

Oscillator 1

synced to

Oscillator 2

The arrows between the oscillator select buttons show how the oscillators
are paired, as does the following table.

Oscillators

14

Dave Smith Instruments

Slave Osc Master Osc

1 2

2 3

3 4

4 1

The effect of Sync is much more easily heard than explained. Here’s a
simple example of how to use Sync.

1. Load the Basic Patch from the Global menu. Oscillator 1 and 2
shaPe is set to sawtooth and oscillators 3 and 4 are off.

2. Turn oscillator 2 oUtPUt level to 0. Only oscillator 1 should be
audible.

3. Turn oscillator 1 sync on.

4. Now turn oscillator 1 Pitch while playing the keyboard. The
harmonic content changes, but not the fundamental pitch. Now do
the same thing while turning oscillator 2 Pitch. (Remember: only
oscillator 1 should actually be audible.) The fundamental pitch
changes, but the harmonic content is relatively consistent. Oscillator
2 is the master and oscillator 1 is the slave.

Tip: Use glide, an envelope generator, an LFO, the mod wheel, or

other modulation source to sweep the pitch of a slave oscillator.

Of course, each of the four oscillators can be synced, so it’s possible to
have two pairs of synced oscillators or to sync oscillators in series (an
oscillator synced to a synced oscillator, synced to a synced oscillator…).

Note: The oscillator 1 sUB octave does not sync to oscillator 2. To

sync oscillator 1 and have a sub octave that plays in tune with oscil­lator 2, use one of the other oscillators as a sub.

Output Level: 0…127—Sets the output level for each of the oscillators.

Note: When using three or four oscillators, it may be necessary to

reduce the levels of each to avoid clipping.

Frequency Modulation (FM): 0…127—Allows one oscillator—called

the modulator, for the purposes of FM synthesis—to modulate the
frequency of another oscillator—called the carrier. The arrows between

Prophet 12 Operation Manual

Oscillators

15

the oscillator select buttons show the modulator/carrier relationship
between the oscillators, as does the following table.

Carrier Modulator

Oscillator 1 Oscillator 2

Oscillator 2 Oscillator 3

Oscillator 3 Oscillator 4

Oscillator 4 Oscillator 1

Turning up FM for oscillator 1 causes it to be modulated by oscillator 2,
turning up FM for oscillator 2 causes it to be modulated by oscillator 3,
and so on.

Note: The indicated order of modulation is really just a handy short-

cut. In fact, you can route any oscillator to another using the modula­tion matrix. See Modulation on page 32 for more information.

Amplitude Modulation (AM): 0…127—As with FM, AM uses the oscil-

lators as carrier/modulator pairs. But with AM, the modulator modulates
the carrier’s amplitude, not its frequency. As with FM, any oscillator

routing combination can be congured using the modulation matrix.

Glide Amount: 0...127—Sets the oscillator glide (portamento) amount.

Glide can be set independently for each oscillator. Low values are
shorter/faster. The gliDe switch must be on to hear the effect of gliDe
amoUnt. For a detailed explanation, see Glide on page 36.

Tip: To set gliDe amoUnt for all oscillators simultaneously, press

and briey hold any of the oscillator select buttons until all of them

are lit. Then adjust gliDe amoUnt. Press any oscillator select button
to exit.

Slop: 0…127—Adds random detuning to the oscillator to emulate the

tuning instability of voltage controlled analog oscillators, from subtle,
barely perceptible amounts to wildly out of tune.

Oscillator 1 Sub Octave: 0…127—Controls the level of a sine wave

oscillator pitched one octave below oscillator 1.

Oscillators

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Dave Smith Instruments

Character

The Character controls affect the sonic character of the mixed output
of the oscillators. The effect may or may not be subtle and may be
dependent upon the frequency and harmonic content of the audio being
processed. For example, Girth boosts and enhances low frequencies, so
the effect upon high frequency content is minimal.

Girth: 0…127—A low shelf lter to boost low frequencies, with some

extra harmonic modication at higher settings.

Air: 0…127— A high shelf lter to boost high frequencies, with some

extra harmonic modication at higher settings.

Hack: 0…127—Reduces the bit depth of the mixed output from the oscil-

lators.

Decimation: 0…127—Reduces the sample rate of the mixed output from

the oscillators.

Drive: 0…127— Emulates tape saturation.

Prophet 12 Operation Manual

Character

17

Low-Pass Filter

The Prophet 12 features one analog resonant low-pass lter per voice.
The lter is switchable between 2- and 4-pole modes and has a dedi­cated ve-stage (delay/attack/decay/sustain/release) envelope generator,

capable of looping the delay, attack, and decay segments. There are also

controls for modulating the lter cutoff with the keyboard and envelope

amount with keyboard velocity.

4-Pole—Selects the lter conguration. When lighted, the lter is in

4-pole mode. A 4-pole, low-pass lter rolls off frequencies above the

cutoff frequency at a slope of 24dB per octave. When the button is off,

the lter is in 2-pole mode and has a slope of 12dB per octave and a

more gradual roll-off of the higher frequencies. Frequencies below the
cutoff pass through unaffected, hence the name “low-pass.”

Frequency: 0...164—Sets the low-pass lter’s cutoff frequency over

a range of more than 13 octaves, stepping in semitones. The cutoff
transistions smoothly across the values when the frequency is swept.

Resonance: 0...127—Emphasizes a narrow band of frequencies around

the cutoff frequency. In 4-pole mode, high levels of resonance can cause

the lter to self oscillate. In 2-pole mode, resonance is much more subtle

and self-oscillation does not occur.

Key Amount: 0...127—Sets the amount of modulation from the

keyboard to FreqUency (the lter’s cutoff frequency). A setting of 64 will
step the lter in semitone increments for each note, 32 would be quarter-

tones, and so on.

VelocityEnvelope Amount: 0...127—Enables keyboard velocity to

modulate the lter enveloPe amoUnt.

Envelope Amount: -127...127—Sets the amount of modulation from

the low-pass lter envelope to the low-pass lter frequency. The modula­tion amount can be positive or negative, allowing for inverted envelope
control.

Note: The low-pass frequency setting may limit the effect of the

envelope on the lter. For example, if FreqUency is all the way up, a
positive envelope amount will have no effect on the lter.

Low-Pass Filter

18

Dave Smith Instruments

Delay: 0...127—Sets a delay between the time the envelope is gated on

and when the Attack segment actually begins.

Attack: 0...127—Sets the attack time of the envelope.

Decay: 0...127—Sets the decay time of the envelope.

Sustain: 0...127—Sets the sustain level of the envelope.

Release: 0...127—Sets the release time of the envelope.

Delay

Amplitude

Time

Repeat: Off, On—When on, the Delay, Attack, and Decay segments of

Attack

Decay

DADSR Envelope

Sustain

Release

the envelope repeat. Sustain still affects the level at which the Decay

segment ends, but—instead of sustaining at a xed level while a note is

gated on—Delay, Attack, and Decay loop until the note is turned off. The
Release segment begins when the note is gated off, just as it does when
Repeat is off. See the illustration on the following page.

Prophet 12 Operation Manual

Low-Pass Filter

19

On

Off

A

B

C

A: The gate generated by pressing, holding, and then releasing a key.
B: Corresponding DADSR envelope behavior with Delay on and Repeat off.
C: Behavior of the same envelope with Repeat on.

Low-Pass Filter

20

Dave Smith Instruments