Dave Smith Instruments TETR4 Operation Manual

Operation Manual

Tetra

Operation Manual

Version 1.2

February 2010

Dave Smith Instruments

1210 Cabrillo Hwy N

Half Moon Bay, CA 94019-1449

USA

©2009 Dave Smith Instruments

www.DaveSmithInstruments.com

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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
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Contents

Quick Start................................................................................................. 1

Getting Connected ....................................................................................3

Front Panel Controls .................................................................................5

Basic Operation......................................................................................... 9

Global Parameters ..................................................................................13

Program Parameters............................................................................... 17

Oscillator Parameters ..........................................................................17

Miscellaneous Oscillator Parameters .................................................. 18

Mixer Parameters ................................................................................19

Feedback Parameters .........................................................................19

Low-pass Filter Parameters................................................................. 19

VCA Parameters.................................................................................. 20

LFO Parameters .................................................................................. 21

Envelope 3 Parameters .......................................................................22

Modulation Parameters .......................................................................23

Unison Parameters.............................................................................. 24

Push It Switch Parameters ..................................................................25

Keyboard Mode Parameters................................................................25

Clock Parameters ................................................................................ 26

Arpeggiator Parameters ......................................................................26

Sequence Parameters......................................................................... 27

Name Parameter .................................................................................28

Combos ...................................................................................................29

Creating a Combo ...............................................................................29

Combos and Multi Mode...................................................................... 31

Using Poly Chain..................................................................................... 32

A Note About Poly Chain and Mopho.................................................. 32

Using USB............................................................................................... 35

Modulation Destinations.......................................................................... 37

Modulation Sources ................................................................................39

Parameter List.........................................................................................40

MIDI Implementation ............................................................................... 41

MIDI Messages.................................................................................... 41

NRPN Messages ................................................................................. 44

Global Parameter Data........................................................................ 45

Program Parameter Data ....................................................................46

Combo Parameter Data....................................................................... 52

Sysex Messages .................................................................................56

Packed Data Format............................................................................ 61

Hidden Functions .................................................................................... 62

1

Quick Start

Thanks for purchasing your Tetra synthesizer! Listen to the sounds, twiddle
some knobs, have some fun!

Please Register!

Please go to www.davesmithinstruments.com and register your synth. If you
purchased directly from us, there is no need to register — we already have your
contact information.

Powering Up

So, plug in the power supply, connect (in stereo!!) to your mixer/sound system,
and start playing!

You can use the P

USH IT switch to trigger sounds without a keyboard. If you’re

using a MIDI keyboard, try applying keyboard pressure (aftertouch) and the
mod wheel. Many sounds are fairly simple at first, then come alive when you
use the controllers. With other sounds, you may need to hold the notes a while to
let the sound unfold. Playing in different ways has a big effect on the programs.

Selecting and Editing Programs, Combos, and Global Settings

Use S

ELECT or the increment and decrement (+ and -) switches to step through

the programs. Hold the switches down briefly to increment or decrement the
bank. There are 4 banks of 128 programs. Banks 1 and 2 are the Prophet ’08
factory programs.

If you want to edit a program, just turn any knob. The new value will be
displayed in the bottom line of the LCD (the top line displays the programmed
value for handy reference).

After turning knobs, just press the Mode (P

ROGRAM/COMBO/GLOBAL) switch to

exit Edit Mode and return to Program Mode, allowing you to change programs
again.

While in Program Mode, press the Mode switch again to change to Combo
Mode. Combos contain a combination of four different programs—one per
voice—that can be used to play polyphonically or in unison, or to play four
different sequences simultaneously.

Press and hold the Mode switch briefly to display the Global menu and change
higher level parameters such as MIDI channel number, Transpose/Detune, and
so on. The S

ELECT knob changes the displayed page and increment and

decrement change the values. These settings are remembered when the synth is
turned off.

2

Summary

You should be up and running now; for more operation information, read on. Or,
just look up specific parameters for detailed notes. Pages 35 through 39 contain
a handy reference for mod destinations and sources. At some point you should
read through the manual to discover all the little features that you might not
notice at first.

Don’t forget you get a free editor for Mac OS or Windows with your purchase.
Download it from www.soundtower.com/tetra.

I should mention that this manual does not include explanations of basic analog
synthesizer functions. It assumes you already know what an oscillator is, how a
low-pass filter affects the sound, what an ADSR envelope looks like, and so on.

Fortunately, these days it is quite easy to find such resources on the Internet. If
you want to learn the lingo and the basics, just try a search in Google (or the
search engine of your choice), something like “analog synthesizer tutorial.”
You’ll find plenty of good reading material.

Have fun!

Dave Smith

Special thanks to:

Tim Ande, Dave Polich, Ravi Sharma, James Terris, Stefan Trippler, and Jason
Ware for their voicing work. Thanks also to the authors of the Prophet ’08
programs, many of which are used in Tetra. Finally, the DSI Team: Chris
Hector, Andrew McGowan, Joanne McGowan, and Tracy Wadley.

3

Getting Connected

Tetra has several inputs and outputs on its back panel.

Power Input — Connect the power supply included with your Tetra. The power

supply comes with different AC adaptor prongs that allow it to work anywhere
in the world. If for whatever reason you need to use a different supply, it must
match the specifications printed on the front panel.

Note: The power supply label says “Evolver” on it; we use the same
supply for the mono Evolvers, Mopho, and the Prophets.

USB — Tetra transmits and receives MIDI data via this standard, Type B, USB

receptacle.

MIDI In — To receive MIDI data from another device, connect this to the other

device's MIDI Out.

MIDI Out — To send MIDI data to another device, connect this to the other

device's MIDI In. This output can also be configured as a MIDI Thru using the
MIDI Out Select parameter in the Global menu.

Poly Chain Out — Up to four Tetras can be chained for increased polyphony

and one or two Tetras can be poly chained with a Prophet ’08. For details, see
Using Poly Chain on page 32.

Note: When Poly Chain is turned off in the Global menu, the Poly Chain
Out simply mirrors the MIDI Out and transmits the same data.

Audio Outputs — Tetra has four, unbalanced, ¼ inch outputs. 1/Left and

2/Right are the summed outputs of all four voices in Stereo or Mono mode and
are typically used for “normal” polyphonic or unison playing. They are also the
direct outputs of voices 1 and 2 in Quad mode. Outputs 3 and 4 are the direct
outputs of voices 3 and 4, respectively, and are always mono. The individual,
direct outputs are typically used in Multi Mode or Combo Mode, so that each
voice can be mixed and processed separately. For more about the Audio Out and
Multi Mode parameters, see Global Parameters on page 13.

Phones — A ¼ inch stereo headphone jack.

4

5

Front Panel Controls

Select — Use SELECT to change and scroll through programs and combos. Also

used to select parameters in Global mode.

Mode (Program/Combo/Global) — Tetra has four modes of operation:

program, combo, global, and edit. Press the button to toggle between Program
and Combo Mode.

When in Program Mode, the display shows the name, number, and bank of the
current program. Editing any of the parameters puts Tetra into Edit Mode and
displays the last parameter edited and its stored and edited values. To return to
Program Mode, simply press the mode switch. See Program Parameters starting
on page 17 for more information.

In Combo Mode, the display shows the name and number of the current combo.
Editing any of the parameters puts Tetra into Edit Mode and displays the voice
(V1, V2, V3, or V4) being edited, the last parameter edited and its edited value.
To return to Combo Mode, simply press the mode switch. See Combos on page
29 for more information.

Global mode is accessed by briefly holding down the mode

button. The Global

menu is displayed. Use S

ELECT to scroll the Global menu and the increment and

decrement (+ and -) buttons to change the settings. To return to Program or
Combo Mode, simply press

the mode button. See Global Parameters on page 13

for more information.

6

Write — Use WRITE to save an edited program or combo to any of Tetra’s

memory locations. To execute the write operation, press the increment (+)
button.

To store a program or combo in a different location, press the W

RITE button and

change the destination using the S

ELECT knob before executing the write.

Note: You can also change program banks by holding the increment (+)
and decrement (-) buttons, but be careful! If you hit the increment button
quickly, it saves the program wherever you are at that point. If you want
to change banks, just be sure to hold the button until you see the bank
change.

To cancel a write, press W

RITE, decrement (-), or the mode button. WRITE is

also used to execute certain operations in the Global menu.

Volume — The master volume control for all of Tetra’s audio outputs and the

headphone output.

Increment/Decrement — The increment and decrement (+ and -) controls are

used to step through programs in Program Mode, combos in Combo Mode, to
change values in the Global menu, and to confirm or cancel various operations.
In Edit Mode they increase/decrease the parameter value. They are also used to
select Tetra’s four program banks. Hold increment briefly to switch to the next
highest bank; hold decrement to switch to the next lowest bank.

Assignable Parameters 1-4 — Any of Tetra’s program parameters can be

edited from the front panel using the ASSIGNABLE PARAMETERS controls and the
assignments for the controls are saved per program, to best suit that program. In
other words, the assignments for the controls can be completely different from
one program to another.

In Combo Mode, each of the four controls is routed to the respective voice. That
is, parameter 1 controls an assigned parameter for voice 1, parameter 2 controls
voice 2, etc.

See also Edit B/Combo below for more information.

Assign Parameters — When the ASSIGN PARAMETERS LED is lit, turn any of

the ASSIGNABLE PARAMETERS controls to select from the list of program
parameters. Press A

SSIGN PARAMETERS again (turn the LED off) to use the

ASSIGNABLE PARAMETERS controls to edit the selected parameters. For a
description of the parameters, see Program Parameters beginning on page 17.
For a list of the parameters, see page 40.

7

Edit B/Combo — This button behaves differently depending upon the current

mode. In Program Mode, it switches between program layers. Each program has
two layers, A and B. Each layer can be a complete, separate patch. The layers
are used in conjunction with the KeyMode parameter for creating stacked or
split programs. When E

DIT B/COMBO is active, the front panel controls the B

layer.

Note: The A

SSIGNABLE PARAMETERS are the same for both layers.

In Combo Mode, E

DIT B/COMBO is used to access various combo parameters.

Press E

DIT B/COMBO once to edit voice 1 parameters. Press the button

repeatedly to cycle through the voices and exit Edit Mode. See Combos on page
29 for more information.

Note: In Combo Mode or when Multi Mode is turned on in the Global
menu, a program’s B layer is ignored.

Pitch — Controls the base frequency of the oscillators. The relative interval

between the two oscillators is in each voice is maintained, even when the
extremes are reached.

Cutoff — Controls the filter cutoff.

Resonance — Controls filter resonance.

Note: The filter will only self oscillate when in 4-pole mode. See Low­pass Filter Parameters on page 19 for more information.

Attack — Simultaneously adjusts the attack portion of all envelope generators:

filter, amplifier, and Envelope 3.

Decay/Release — Simultaneously adjusts the decay and release portions of all

envelope generators: filter, amplifier, and Envelope 3.

Push It! — The PUSH IT button is a manual trigger to play Tetra. In Program

Mode, it can trigger a specific note (at a specific velocity) or a gated sequence,
latch notes or sequences on and off, and manually step through a sequence. For
more information, see Program Parameters, beginning on page 17.

In Combo Mode, the P

USH IT button cycles through the voices for polyphonic

combos and plays all voices simultaneously when unison is on. See Combos on
page 29 for more information.

9

Basic Operation

Tetra has multiple personalities. It is a four-voice, analog poly synth, a sort of
“mini Prophet.” But the voice architecture is based on Mopho, so it has a couple
of sonic tricks up its sleeve—specifically sub-octave generators and feedback—
that are absent from the Prophet. Tetra is also a four-part, multitimbral synth
with separate outputs, essentially four Mophos in one very compact box. And
it’s a voice expander for other Tetras or for a Prophet ’08. (Program banks 1 and
2 are the Prophet ’08 factory programs.)

In designing Tetra, the goal was to make a great sounding synth that was also
affordable. Toward that end, we wanted to give players enough control over
parameters to make it useful for performance, so we came up with a
combination of “hard-wired” commonly used controls and user-assignable
controls. Any of Tetra’s parameters can be edited in real time from the front
panel controls. But we also recognize that may not be the quickest or easiest
way to program sounds from scratch. A free editor for Mac OS and Windows
gives you easy access to all of Tetra’s program parameters. Download it here:
www.soundtower.com/tetra. Also, an advanced version of the editor with more
features can be purchased from our Web site.

Note: The Prophet ’08’s controls map directly to Tetra’s, so if you have a
Prophet ’08, you can use it as a MIDI control surface for Tetra.

Programs

When Tetra first powers up, it is in Program Mode. The top line of the LCD
shows the Program (1…128) and Bank (1…4) number of the currently selected
program, and the bottom line shows the 16-character name of the program.
S

ELECT changes the program. The program can also be changed by pressing the

increment (+) or decrement (-) switches. To increment to the next bank, hold the
increment switch briefly; to decrement to the previous bank, hold the decrement
switch.

To edit a program, simply turn any knob. The A

SSIGNABLE PARAMETERS knobs

have been preset to useful parameters for the factory programs. To change a
knob’s assignment, press A

SSIGN PARAMETERS to light the LED. Turning any of

the ASSIGNABLE PARAMETERS knobs now will scroll through the list of available
parameters. Choose one or more parameters to edit and then press A

SSIGN

PARAMETERS again to exit the assignment mode (ASSIGN PARAMETERS LED
should now be off). See Program Parameters on page 17 for a detailed list of all
parameters and their functions. After editing parameters, press the Mode
(P

ROGRAM/COMBO/GLOBAL) switch to exit Edit Mode and return to Program

Mode.

10

Combos

When in Program Mode, press the Mode switch to enter Combo Mode. Combos
are combinations of four programs, one for each voice. In Combo Mode, use
S

ELECT and increment/decrement to change combos. Each of the ASSIGNABLE

PARAMETERS knobs controls a parameter for its respective voice: knob 1 for
voice 1, knob 2 for voice 2, and so on. And the bottom row of knobs affects all
voices and programs in the combo. For more about combos, see Combos on
page 29.

Saving a Program or Combo

To save a program or combo, press W

RITE. To store in a different location, use

SELECT to choose the target destination, and hold the increment or decrement
switch to choose a different bank (programs only; there is only one bank of
combos). Press increment (+) to complete the write operation or decrement (-) to
cancel (or press W

RITE again).

Voice Architecture and Feedback

As you can see from the illustration on the following page, the left Audio Output
goes through a programmable-gain pre-amp (controlled by the Feedback Gain
parameter), then through a VCA for feedback volume control, and then to the
filter input. Turning up the Feedback Volume will cause varying amounts of the
audio output to be mixed back in pre-filter, individually per voice. For most
purposes, small amounts of feedback are most useful and the resulting effect is
similar to an overdrive distortion. Higher levels of feedback can get very
squirrelly and rude (which may be exactly the effect you’re looking for).

F

EEDBACK GAIN also affects the level of the feedback signal, so you’ll typically

want to start with FEEDBACK GAIN turned down.

Several of the factory programs already have some level of feedback
programmed in, as often indicated by the letters “FB” following the name. To
hear the effect of Feedback Volume and Feedback Gain, call up one of those
programs and vary those parameters.

Further Reading

For information about using Tetra multitimbrally, see “Multi Mode” and “Audio
Out” in Global Parameters on page 13.

For information about using Tetra as a voice expander with a Prophet ’08 or
another Tetra, or using Mopho as an additional voice for Tetra, see Using Poly
Chain on page 32.

11

13

Global Parameters

Tetra’s Global parameters affect all programs globally. Examples include MIDI
channel and fine tune. To edit the Global parameters, hold down the Mode
switch (Program/Combo/Global) until the G

LOBAL LED lights. The SELECT

knob changes the global parameter and the increment and decrement buttons
change the value.

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

semitones.

Fine Tune: -50…+50 — Master Fine Tune control; 0 centered. Steps in cents (50

cents = 1/2 semitone).

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

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

Clock: see table — Selects the MIDI clock status.

Display MIDI Clock Setting

Internal

MIDI clock is neither sent nor received

MIDI Out

MIDI clock is sent

MIDI In

MIDI clock is received

Midi In/Out

MIDI clock is received and transmitted

MIDI Parameter Send: NRPN, CC, Off — Changes to the values of Tetra’s 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 41 for
details.

Note: NRPNs are the preferred method of parameter transmission, since
they cover the complete range of all parameters, while CCs only handle
the main parameters.

MIDI Parameter Receive: All, NRPN, CC, Off — Sets the method by which Tetra

receives parameter changes via MIDI. As with transmission, NRPNs are the
preferred method, though some controllers may only be able to send CCs.

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

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

MIDI SysEx: 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 56 for details.

14

MIDI Out Select: Out, Thru — MIDI Out can be switched to MIDI Thru to

daisychain multiple MIDI devices.

Poly Chain: Off, Out 1, Out 4, Out 8, Out 12, In End, InOut4, InOut8 —

Using
Poly Chain, up to four Tetras can be chained together for increased polyphony.
One or two Tetras can also be chained with a Prophet ’08 for twelve- or sixteen­note polyphony. And a Tetra and Mopho can be chained for five-note
polyphony. For a more complete description of Poly Chain and how to use it,
see Using Poly Chain on page 32.

Multi Mode: Off, On — Multi Mode enables Tetra to respond to four separate

MIDI channels for multitimbral playback. With Multi Mode on, voice one
responds to the base MIDI channel and the other three voices respond to the next
three consecutive channels. For example, if Tetra’s base channel setting is 3,
voice one responds to MIDI channel 3, voice two to MIDI channel 4, and so on.

Note: For all four voices to play in Multi Mode, the base channel must
be 13 or lower.

Local Control: Off, On — When on (the default), the front panel controls

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

Audio Out: Stereo, Mono, Quad, Q LR34 — Tetra has four audio outputs:

1/Left, 2/Right, 3, and 4. Stereo operation is the default. When set to Stereo, a
stereo mix of all voices is available via the Left and Right outputs.

Note: Outputs 3 and 4 are always direct outputs for voices 3 and 4 and
are mono, regardless of the Audio Out mode. Inserting a plug into output
3 or 4 does not remove that voice from the mix outputs when in Stereo or
Mono mode.

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

Quad directs each of the four voices to its respective, mono output.

Note: Outputs 3 and 4 are noticeably louder than the other two outputs.
This is normal. Outputs 3 and 4 are always monophonic and, therefore,
do not require as much headroom as the mix outputs, which have to
accommodate up to four voices at one time without distorting. The higher
level provides optimum signal-to-noise ratio. Compensate for differences
in level with a mixer.

15

Choosing “Q LR34” is similar to Quad, but voices 1 and 2 retain whatever
panning effects are present in the assigned programs and the stereo outputs of
those voices are present at both the Left and Right outputs.

PotMode: Relative, Passthru, Jump –Tetra’s Cutoff, Resonance, and Volume

controls are potentiometers or “pots.” There are three pot modes to determine
how the synth reacts when the programmable parameters—Cutoff and
Resonance—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.

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 first 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.

Balance V 1 - 4: -14…+14 — Adjusts the left/right balance of each voice by

approximately +/- 4 dB.

Basic Patch — Press the WRITE button to load a basic patch into the edit buffer.

(The patch will not actually be written to the current program location unless
intentionally written to memory in Program Mode using the W

RITE button.)

Reset Globals —

Tetra does not have a full hardware reset, but select this
parameter and press WRITE to reset the global parameters to their factory
defaults.

MIDI SysEx Dump: see table — Allows dumping of programs and combos in

SysEx format via MIDI.

16

Display MIDI Transmit Operation

Current Program

Dump current program

Current Prog Bank

Dump all 128 programs in current bank

All Progrm Banks

Dump all programs in all 4 banks

Current Combo

Dump current combo

Combo Bank

Dump all combos

All Progs Combos

Dump all program banks and combos

Current Prog P08

Dump current program in Prophet ’08 format

CurrentProgMopho

Dump current program in Mopho format

Program Bank P08

Dump current bank in Prophet ’08 format

Prog Bank Mopho

Dump current bank in Mopho format

Press the WRITE switch to start transmission. This feature is handy for saving
Programs on a computer in SysEx format, or for sending them to another Tetra
via a direct MIDI connection. The dumps include Program and Bank numbers,
so when received, the programs will be stored in the same location.

Programs can also be exported in Mopho and Prophet ’08 formats.
Features/parameters not available on those instruments are stripped out. For
example, Mopho does not support layers, so only layer A is exported. The
Prophet ’08 does not have feedback or sub-octave generators.

Program Copy Utility — Enables layer A or layer B of a program to be copied

to layer A or B of the same or a different program. The top line displays the
current bank and program. Use increment (+) or decrement (-) to choose the
layer to be copied. Then use S

ELECT to select the destination bank, program, and

layer and increment/decrement to change the values.

17

Program Parameters

All Program parameters can be edited using any of ASSIGNABLE PARAMETERS
controls. To assign a parameter to a control, press the A

SSIGN PARAMETERS

button to light the LED, and then turn any of the knobs (1 through 4) to select a
parameter. A full list of the parameters can be found on page 40. The selected
parameter and value appear in the LCD display. The top line of the LCD
displays the programmed value for reference; the bottom line displays the edited
value.

To then change the value of the parameter you selected, hit the A

SSIGN

PARAMETERS button again, and the same knob will now change the value. You
can also use the increment and decrement switches to adjust parameter values.

Note: Once you are done editing a program, before you save it, you
should consider what parameters you want to access when playing the
new program. Generally, when making a program, we try to assign each
of the 4 knobs to a different parameter that makes sense for that
particular program, providing extra live control.

Though it is certainly possible to perform detailed program generation and
editing using these controls, it is usually much faster to use the free editor
available for Mac OS or Windows. The minimal front panel of the Tetra is
designed for fast, real-time changes in live performance.

Following are descriptions of each Tetra Program parameter.

Oscillator Parameters

Tetra has two analog oscillators per voice. The basic controls for each oscillator
are the same.

Note: There are additional modulation controls that can affect the pitch
of Oscillators 1 and 2. These are covered in other sections of the
Parameter definitions.

Osc Freq: 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 first
octave is 0 (C0, C#0, etc.), the second octave is 1 (C1, C#1, etc.), and so on.

Fine Freq: -50…+50 — Fine Tune control; 0 centered. Steps in cents (50 cents =

1/2 semitone).

Shape: see table — Selects the oscillator waveshape as follows:

18

Display Waveshape

Osc Off

No output

Sawtooth

Sawtooth

Triangle

Triangle

Saw-Tri

Sawtooth — Triangle mix

Pulse xx

Pulse Wave, with pulse width ranging from minimum
(0) to maximum (99). The pulse width will turn off at the
two extremes — this allows some interesting
modulation possibilities. A square wave will be at Pulse

50.

Glide: 0…127 — Sets the oscillator glide (portamento) rate. Glide can be set

independently for each oscillator. Low values are faster. See “Glide Mode”
below in Miscellaneous Oscillator Parameters for additional Glide settings.

Keyboard: On, Off — Turns keyboard tracking for the oscillator on and off.

Sub Osc 1: 1...127 — Sub-oscillator 1 generates a square wave pitched one

octave below oscillator 1. This parameter controls the level.

Sub Osc 2: 1...127 — Sub-oscillator 2 generates a square wave pitched two

octaves below oscillator 2. This parameter controls the level.

Miscellaneous Oscillator Parameters

Sync 2-> 1: Off, On — Turns oscillator hard sync on. With sync on, whenever

oscillator 2 resets, it will force oscillator 1 to reset for the classic hard sync
sound.

Glide Mode: see table — Sets the way the oscillators respond to Glide settings.

Display Glide mode

FixRate

The Glide rate is fixed. The time to
transition from one note to another varies
depending upon the interval between the
notes.

FixRate A

The same, but Glide is only applied when
played legato; that is, when a new note is
hit while another note is still held.

FixTime

The Glide time is fixed. The time to
transition from one note to another is the
same, regardless of the interval.

FixTime A

The same, but Glide only is applied when
played legato; that is, when a new note is
hit while another note is still held.

Osc Slop: 0…5 — The amount of random oscillator frequency slop. The analog

oscillators in Tetra are very accurate, and will not drift. This works great for

19

accurate sounds, and allows precise de-tuning. The Oscillator Slop parameter
allows subtle amounts of frequency drift. For larger amounts, use a random LFO
or white noise mod.

Pitch Wheel Range: 0…12 — Sets the bend range, in semitones, of the pitch

wheel. The setting is the range in the positive or negative direction. For
example, a setting of 7 lets you bend a note up or down by a fifth.

Mixer Parameters

Osc Mix: 0...127 — Enables the outputs of Oscillators 1 and 2 to be mixed in

varying amounts. A setting of 0 is equivalent to 100% Oscillator 1 and 0%
Oscillator 2. A setting of 127 is just the opposite. A setting of 64 is essentially a
50-50 mix of both oscillators.

Noise Level: 0…127 — Controls the volume of white noise mixed into the

filter.

Feedback Parameters

Feedback Volume: 0...127 — This controls the amount of audio from the left

channel of each voice fed back into that voice's mixer pre-filter. As the value
increases, so does the effect of the feedback.

Feedback Gain: 0…127 — Feedback Gain boosts the level of the feedback

signal and is interactive with and dependent upon Feedback Volume. If
Feedback Volume is set to 0, then Feedback Gain has no effect. (There is no
feedback signal to boost.) However, Feedback Gain combined with higher levels
of Feedback Volume can result in effects ranging from pleasing distortion to
squirrelly harmonic weirdness.

Low-pass Filter Parameters

Each of Tetra’s voices utilizes a switchable, 2- or 4-pole analog low-pass filter
coupled with a 4-stage (plus delay) ADSR envelope generator.

Frequency: 0…164 — Sets the base filter cutoff frequency over more than 13

octaves. This control steps in semitones.

Resonance: 0…127 — Sets the Resonance level of the filter. At high settings

the filter will self-oscillate in 4-pole mode. If the filter does not oscillate, switch
to 4-pole mode.

Keyboard Amount: 0…127 — Sets the amount of keyboard (MIDI note) to the

filter cutoff. A setting of 64 will step the filter one semitone for each note, 32
would be half-semitones, and so on.

20

Audio Mod: 0...127 — Controls the amount of audio from Oscillator 1 used to

modulate the filter cutoff frequency. For filter-only audio, set O

SCILLATOR MIX

to 127, O

SCILLATOR 2 SHAPE to Off, and OSCILLATOR 1 SHAPE to the desired

waveshape. This is useful for bell-like FM sounds. A wide range of sounds can
also be made using A

UDIO MOD with the oscillators routed normally through the

filter.

Config: 2 Pole, 4 Pole — Selects either 2- or 4-pole operation for the filter.

Envelope Amount: -127…+127 — Sets the amount of filter envelope routed to

the cutoff frequency. This can be positive or negative, allowing inverted
envelope control of the filter.

Envelope Velocity: 0…127 — Amount of key velocity controlling the level of

the filter envelope.

Delay: 0...127 — Sets a delay between the time the filter envelope is triggered

and when the Attack portion actually begins.

Attack: 0…127 —

Sets the Attack time of the filter ADSR envelope generator.

Decay: 0…127 — Sets the Decay time.

Sustain: 0…127 — Sets the Sustain level.

Release: 0…127 — Sets the Release time.

VCA Parameters

VCA Level: 0…127 — Sets a base level for the VCA (Voltage Controlled

Amplifier). This allows the VCA to be essentially bypassed, which is necessary
for Programs that drone.

Note: If VCA L

EVEL is on full, Envelope Amount has no effect. You

normally want VCA LEVEL set to zero. For droning sounds you will
probably turn the VCA Level up.

Env Amount: 0…127 — Sets the amount of VCA envelope to the VCA level.

Env Velocity: 0…127 — Sets the amount of keyboard velocity controlling the

level of the VCA envelope.

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

triggered and when the Attack portion actually begins.

Attack: 0…127 —

Sets the Attack time of the VCA ADSR envelope generator.

21

Decay: 0…127 — Sets the Decay time.

Sustain: 0…127 — Sets the Sustain level.

Release: 0…127 — Sets the Release time.

Pan Spread: 0…127 — There is a pan circuit after the VCA that pans the audio

in the stereo field individually per voice. With a Pan Spread of 0, all four voices
are panned dead center. As you turn up Pan Spread, each voice is gradually
moved away from the center by different amounts. Every other voice goes in a
different direction, left or right. This provides a wide stereo field as the voices
play.

Note: Any modulation to pan will individually move each voice from its
static position as set by Pan Spread.

Program Volume: 0…127 — Sets the volume of the current program to match

volumes between programs.

Note: There is enough gain in the synth voice that with some settings,
some mild clipping distortion may be heard. If this happens, try lowering
the Voice Volume, and/or the VCA Envelope Amount (or VCA Velocity
Amount).

LFO Parameters

Tetra has four Low Frequency Oscillators (LFOs). The same parameters are
available for each.

Frequency: 0…150, sync — Sets the LFO frequency. Range 0—150 for un-

synced LFO; speed ranges from slow (30 seconds) to very fast — at 90 (8 HZ,
C-2) and above the speed steps in semitones, up to 150 (261 Hz, middle C).

Note: Some of the analog functions may not respond well to the fastest
LFO speeds, due to speed limitations of the control voltages; but they
will certainly generate some interesting sounds.

Above 150, the sync speeds are as follows:

22

Display Timing Sync

32 Steps

Sequence speed divided by 32; i.e. one LFO cycle
takes 32 steps

16 Steps

Sequence speed divided by 16

8 Steps

Sequence speed divided by 8

6 Steps

Sequence speed divided by 6

4 Steps

Sequence speed divided by 4

3 Steps

Sequence speed divided by 3

2 Steps

Sequence speed divided by 2

1.5 Step

Sequence speed divided by 1.5

1 Step

One cycle per step

2/3 Step

Two cycles every three steps

1/2 Step

Two cycles per step

1/3 Step

Three cycles per step

1/4 Step

Four cycles per step

1/6 Step

Six cycles per step

1/8 Step

Eight cycles per step

1/16Step

Sixteen cycles per step

Shape: see table — Selects the LFO waveshape:

Display LFO Shape

Triangle

Triangle

Rev Saw

Reverse Sawtooth

Sawtooth

Sawtooth

Square

Square Wave

Random

Random — changes once per cycle for
sample-and-hold effects

Amount: 0…100 — Sets the amount of LFO routed to the destination.

Key Sync: Off, On — When on, the LFO is re-started each time a new note is

played. Key Sync is set independently on each LFO.

Destination — See Modulation Destinations on page 35 for a list of possible

destinations.

Envelope 3 Parameters

Envelope 3 is an auxiliary envelope for modulating various destinations. It can
even be used as a sort of LFO using the Repeat parameter, which is unique to
Envelope 3.

Destination — Sets the Envelope 3 destination. See Modulation Destinations on

page 35 for a list of possible destinations.

23

Amount: -127…+127 — Sets the amount of Envelope 3.

Env Velocity: 0…127 — Sets the amount of key velocity controlling the level of

envelope 3.

Env Delay: 0…127 — Sets a delay between the time Envelope 3 is triggered and

when the Attack portion actually begins.

Env Attack: 0…127 — Sets the Attack time of Envelope 3.

Env Decay: 0…127 — Sets the Decay time.

Env Sustain: 0…127 — Sets the Sustain level.

Env Release: 0…127 — Sets the Release time.

Repeat: Off, On — When on, causes the delay, attack, decay, and sustain

portions of Envelope 3 to loop for as long as the envelope is gated on.

Modulation Parameters

The Modulation Parameters let you configure the modulation routing and
amount for Tetra’s four general-purpose modulation slots as well as for MIDI
controllers (Mod Wheel, Key Pressure, Breath Control, Velocity, and Foot
Controller).

Since each Tetra mod source has a single destination, the four general purpose
Mods provide a way to send a mod source (such as a sequence or LFO) to
additional destinations, with a different amount. There are also additional mod
sources available here, such as Noise, allowing a wide variety of possibilities.

To configure a general-purpose modulation slot, select the appropriate
modulator (Mod 1, Mod 2, Mod 3, or Mod 4), and use the Source, Destination,
and Amount parameters to route the modulation as desired.

To configure modulation for a standard MIDI controller, select the desired
controller and amount, and then set the destination.

Source — Selects a modulation source. See Modulation Sources on page 39 for

possible sources.

Amount: -127…+127 — Sets the amount of modulation.

Destination — Selects a modulation destination. See Modulation Destinations

on page 35 for a list of possible destinations.

24

Mod Wheel Amount: -127…+127 — Sets the maximum amount of modulation

that can be applied from MIDI Continuous Controller 1 (mod wheel).

Mod Wheel Destination — Selects the destination to which the mod wheel is

routed. See Modulation Destinations on page 35 for a list of possible
destinations.

Press Amount: -127…+127 — Sets the maximum amount of modulation that

can be applied from MIDI Channel Pressure (aftertouch).

Press Destination — Selects the destination to which the Channel Pressure is

routed. See Modulation Destinations on page 35 for a list of possible
destinations.

Breath Amount: -127…+127 — Sets the maximum amount of modulation that

can be applied from MIDI Continuous Controller 2 (breath controller).

Breath Destination — Selects the destination to which the breath control is

routed. See Modulation Destinations on page 35 for a list of possible
destinations.

Veloc Amount: -127…+127 — Sets the maximum amount of modulation that

can be applied from MIDI note-on velocity.

Veloc Destination — Selects the destination to which the note-on velocity is

routed. See Modulation Destinations on page 35 for a list of possible
destinations.

Foot Amount: -127…+127 — Sets the maximum amount of modulation that can

be applied from MIDI Continuous Controller 4 (foot controller).

Foot Destination — Selects the destination to which the foot control is routed.

See Modulation Destinations on page 35 for a list of possible destinations.

Unison Parameters

Unison Mode: see table — Sets how voices are allocated and tuned when

unison is on.

Display Key mode

1 Voice

Classic, two oscillator, monophonic mode

All Voices

All available voices stacked in unison

25

AllDetune1-3

All available voices stacked in unison with
increasing levels of detuning among the
voices

Unison Assign: see table — Determines how Tetra responds to keyed notes

when unison is on.

Display Key mode

Low Note

Low note priority

LowRetrig

Low note priority, re-trigger envelopes

HighNote

High note priority

HighRetrg

High note priority, re-trigger envelopes

LastNote

Last note hit priority

LastRetrg

Last note hit priority, re-trigger envelopes

Unison: On, Off — Turns unison on or off. When unison is on, Tetra behaves

like a monophonic synth.

Push It Switch Parameters

These parameters determine the behavior of the PUSH IT switch, Tetra’s manual
trigger.

Note: C0…C10 — Sets the note that plays when PUSH IT is pressed.

Velocity: 0…127 — Sets the MIDI note-on velocity.

Mode: Normal, Toggle — When set to Normal, PUSH IT responds like a key:

press it and a note plays, release it and the note ends. But when set to Toggle,
P

USH IT turns the note on with one press and off with a second press. This is

handy for making a note drone or for latching a gated sequence on.

Keyboard Mode Parameters

The keyboard mode parameters determine how programs are mapped to a MIDI
keyboard or other MIDI controller and provide compatibility with the Prophet
’08’s keyboard modes.

Note: These parameters only appear in Program Mode, not Combo
Mode, and only for layer A.

Split Point: C0…C10 — When in Split mode, sets the key at which the split

occurs. Layer A (voices 1 and 2) is mapped below the split point. Layer B
(voices 3 and 4) is mapped to the chosen split point and above.

26

Key Mode: Normal, Stack, Split — Determines how the layers respond to MIDI

note data in Program Mode. For Normal, layer A plays for the entire key range.
Press E

DIT B/COMBO to switch to layer B.

For Stack, both layers respond to MIDI notes for the entire key range, enabling
two patches to be played simultaneously with a single key stroke. Voices 1 and
2 are assigned to layer A, 3 and 4 are assigned to layer B.

Split assigns layer A from the lowest note to below the split point (see previous
parameter) and layer B from the split point to the highest note.

Note: In Combo Mode and Multi Mode, layer B is ignored.

Clock Parameters

The sequencer and arpeggiator share the BPM and CLOCK DIVIDE settings.

BPM: 30…250 — Sets the programmed tempo for the sequencer in BPM (beats

per minute).

Clock Divide: see table — Sets the note value for each sequence step relative to

the BPM.

Display Tempo Timing Division

Half

BPM/2 Half note

Quartr

BPM Quarter note

Eighth

BPM x 2 Eighth note

8 half

BPM x 2 Eighth note, half swing timing

8swing

BPM x 2 Eighth note, full swing timing

8 trip

BPM x 3 Eighth note triplets

16th

BPM x 4 Sixteenth note

16half

BPM x 4 Sixteenth note, half swing timing

16swng

BPM x 4 Sixteenth note, full swing timing

16trip

BPM x 6 Sixteenth note triplets

32nd

BPM x 8 Thirty-second note

32trip

BPM x 12 Thirty-second note triplets

64trip

BPM x 24 Sixty-fourth note triplets

Arpeggiator Parameters

Tetra’s arpeggiator has four different operating modes and can be synced to a
MIDI clock source.

Note: If the arpeggiator does not seem to be working, check the G

LOBAL

parameters to make sure Clock is set to Internal. If Clock is set to use an

27

external clock source, Tetra must be receiving MIDI clock messages in
order for the arpeggiator to run.

The tempo and note value are determined by the Clock Parameters.

Mode: see table — Sets the order in which the arpeggiator plays notes.

Display Arpeggiator mode

Up

Arpeggiated notes play in ascending
order.

Down

Arpeggiated notes play in descending
order.

Up Down

Arpeggiated notes play in alternately
ascending and descending order.

Assign

Arpeggiated notes play in the order in
which they were struck.

On/Off: Off, On — Turns the arpeggiator on and off. Turning it on will turn off

the Sequencer if it is on.

Sequence Parameters

Tetra features a 4 x 16 “analog-style” step sequencer that can generate four
separate sequence tracks of up to 16 steps each. Each of the 4 voices has its own
sequencer. Individual sequencer tracks can be routed to any standard modulation
destination (see the table on page 35). Using VCA Envelope as a destination, for
example, varies the volume of each step; a destination of Filter or Filter
Envelope Amount will produce different filter settings per step. Typically,
however, at least one sequence is routed to an oscillator to control pitch.

The sequencer is a “gated” sequencer. That is, a note must be played, either
from the P

USH IT switch or via MIDI, in order for the sequence to be heard and

it will continue to play as long as the note is held (gated) .

Note: The P

USH IT switch’s Toggle parameter enables notes (and,

therefore, sequences) to be latched on for sustained playback.

The Clock Parameters determine the note value/tempo of the sequencer. The
actual gate duration for each step is fixed at half the step time. Use the envelopes
to generate notes of longer or shorter duration.

One very useful way to modulate a parameter in sync with a sequence is using
LFOs with sync; LFO frequency runs from 0 to 150, after which you can select
the sync settings. A setting of 16 Steps for LFO Frequency with a Triangle wave
selected and routed to the filter will provide a clean filter sweep over a 16 step
sequence, perfectly in sync! This is much easier (and smoother) than
programming a filter sweep using sequence steps.

28

Note: If the sequencer does not seem to be working, check the GLOBAL
settings to make sure Clock is set to Internal. If Clock is set to use an
external clock source, Tetra must be receiving MIDI clock messages in
order for the sequencer to run.

Seq Trigger: see table — Sets the triggering mode for the Gated Sequencer.

Display Trigger mode

Normal

Sequence plays from the first step when a
key is held, and resets to step 1 each time
a new note is played. Each sequence step
retriggers the envelopes.

No Reset

The same, but does not reset to step 1 on
every note.

No Gate

The keyboard triggers the envelopes; the
sequence steps do not.

NoGateNR

Same, but does not reset with subsequent
notes.

Key Step

Striking a key advances the sequencer
one step.

On/Off: Off, On — Turns the sequencer on and off.

Seq 1, 2, 3, or 4 Destinations — Sets the destination for each of the four

sequence tracks. For a complete list, see Modulation Destinations on page 35.

Seq 1, 2, 3, or 4 Steps: C0…D5+ or 0…125, Reset, Rest — Sets each step value

for each of the four sequence tracks. The values are displayed as both relative
note values and as simple numerical values. Note values are displayed in quarter
tones with a plus sign (+) indicating that the pitch is a quarter tone higher than
the displayed note number. The two highest values are Reset and Rest. Reset
causes the sequence to reset to the first step, enabling sequences of fewer than
16 steps or even sequences in which the tracks are different lengths. Rest inserts
a rest on the selected step.

Name Parameter

Edit Name — The lower LCD line displays the name of the Program with the

active character blinking. When ASSIGN PARAMETERS is lit, the parameter
control changes the position of the active character. When ASSIGN PARAMETERS
is not lit, the parameter control steps through all the available characters for the
active character. The increment and decrement buttons also change the
character.

29

Combos

A combo is a collection of four programs—one per voice—combined to make a
sort of super program. How a combo responds to MIDI note data depends
largely upon whether or not it is monophonic (that is, unison is on) or
polyphonic. The typical uses for a combo are:

Stacked unison—All four voices play from a single key or the PUSH IT button

with four different programs.

Multitimbral sequence playback—Four different programs and their sequences

play back simultaneously from a single key or the PUSH IT button.

“Modular-style” polyphony—Four-voice polyphony with a different program per

voice.

Tetra has 128 combos. To access them, press the mode button to light the
C

OMBO LED. Change combos using SELECT or increment (+) and decrement (-).

The bottom row of knobs (PITCH, CUTOFF, etc.) affects all the programs in the
combo. Though this may not make sense in all cases, changing all four programs
in a combo with a single control makes for some very interesting live editing
possibilities.

Each of the Assignable Parameters knobs controls one parameter for the
respective voice. That is, knob 1 controls a parameter for voice 1, knob 2 for
voice 2, and so on.

Creating a Combo

It probably goes without saying, but it is generally quicker and easier to create
combos using the editor. It can be done without the editor, though.

To create a combo from scratch, press E

DIT B/COMBO while in Combo Mode.

The display shows “Edit V1” to indicate that any edits made affect voice 1 only.
S

ELECT chooses programs from the program banks (layer A only). The display

looks something like this:

C 19 P 26 B2 V1
ManInTheMoon

The top row shows the combo, the program, the bank, and the voice being
edited. The bottom row shows the program name.

Note: Though the program banks can be used as a starting point for
building combos, the actual programs used are copies, so any edits made

30

in Combo Mode do not affect the original programs. The converse is also
true. Say a combo is created using the program “Arid” and then Arid is
subsequently edited in Program Mode. Those changes will not be
propagated to the combo. (The edited program can be reassigned to the
combo, though.) In other words, Combos contain all parameters for all
four voices when saved, and do not rely on mapping to the programs,
making organization and maintenance much easier.

The editor has the ability to copy any combo voice or any program layer (A or
B) to any other combo voice or program layer. This provides a very fast way to
build up combos. For example, say you like the kick drum on voice 1 of a
factory combo. You can copy it and paste it to any voice on a new combo. Then,
you could find a snare from a different combo, and copy it into a different voice
on your new combo. Do the same for the remaining voices and you have a new
customized combo that you can then further edit to your liking.

Use the P

USH IT button or a MIDI controller to audition any changes made to

voice 1.

The A

SSIGNABLE PARAMETERS are initially the same as for the chosen program,

but can be reassigned, if desired, without affecting the assignments in the
original program. Simply press A

SSIGN PARAMS and choose the desired

parameters as in Program Mode.

Note: A few parameters do not appear in Combo Mode, or appear only
on certain voices. In addition to the exceptions noted below, Unison
Mode, Split Point, and Key Mode never appear in Combo Mode.

When satisfied with the selections/edits, press E

DIT B/COMBO again to move on

to voice 2. When assignments have been made for all four voices, press Edit
B/Combo to exit and play the combo.

The combo’s name is set using the Edit Name parameter for voice 1
(A

SSIGNABLE PARAMETER 1) only when EDIT B/COMBO is turned off. And, of

course, don’t forget to save changes using W

RITE. The combo can be saved to

the current, or another, memory location. After pressing WRITE, use SELECT to
choose the target combo number.

There are other parameters that affect how combos play back. If Unison is set to
Off for voice 1 (the Unison on/off parameter only appears under voice 1, not
voices 2 through 4), the combo will play back polyphonically. If the P

USH IT

button is to be used to latch notes on, Push It Mode must be set to Toggle in
each of the voices. To start playback of four sequences simultaneously from the
P

USH IT button, set Unison to On in voice 1, set the Push It Mode to Toggle for

all four voices, and make sure Sequencer is set to On for all four voices. If the

31

Audio Out parameter in the Global menu is set to Quad, each of the voices in a
combo can be processed separately.

The hardware is somewhat limiting for volume control in Combo Mode. The
Program Volume parameter shows up in voice 1 to control voices 1 and 2; and
in voice 3 to control voices 3 and 4. It does not show up in voices 2 or 4.

If you wish to control the volume of individual voices in a combo, use VCA
Envelope Amount per voice. VCA Level, VCA Velocity Amount, and any
modulation to VCA amount will also affect the voice volume.

Combos and Multi Mode

Combos can also be used to “cue up” programs used in Multi Mode. When
Multi Mode is used with an external sequencer, the sequencer typically
determines which programs will play by sending MIDI program change
messages on the relevant tracks and MIDI channels. As an alternative, a
combination of Combo Mode and Multi Mode can be used to recall four
programs—one per voice—and have each voice respond to a different MIDI
channel. For more information about Multi Mode, see Global Parameters on
page 13.

32

Using Poly Chain

Poly Chain enables multiple Tetras to be chained together for increased
polyphony, up to 16 voices. Tetra can also be poly chained with a Mopho or
Prophet ’08. MIDI note data from a keyboard, sequencer, or other controller is
intelligently processed so that, when one synth’s maximum polyphony is
reached, additional notes are passed through the Poly Chain Out jack and routed
to another synth. All that is required is a single MIDI cable for each of the
chained synths and a mixer for combining the audio outputs.

You should have the same programs loaded into all the chained synths. The
easiest way to do that is to use the Dump command in the Global menu to dump
the programs via MIDI from one synth to the other(s).

Note: Tetra’s program banks 1 and 2 come pre-loaded with the Prophet
’08 factory programs.

On the master instrument—the first Tetra in the chain—set Poly Chain to the
number of additional voices that will be chained: Out 1 (for poly chaining a
Mopho), Out 4, Out 8, or Out 12. To chain three Tetras, set Poly Chain on the
intermediate instrument to InOut4. For four Tetras, set the second instrument in
the chain to InOut8 and the third to InOut4. Regardless of how many are
chained together, the last Tetra is always set to In End. You can also use one or
two Tetras to expand the polyphony of a Prophet ’08. See the illustration at the
end of this section for more information.

You can now virtually ignore the slave unit or units, since the controls on the
master will control all units as if they were a single synth. This includes saving a
program; if you save an edited program on the master, it will also save the
program on the slave(s).

Note: If syncing to an external MIDI clock, set MIDI Clock (Global
menu) on the master and any intermediate units to MIDI In/Out. Set the
last instrument in the chain to MIDI In.

When Poly Chain is set to Off, the Poly Chain MIDI out jack simply duplicates
the MIDI out jack.

A Note About Poly Chain and Mopho

Unlike Tetra and the Prophet ’08, Mopho does not have layered programs. It is
only one voice and so can not do stacked or split programs. Because of that,
when poly chaining a Mopho (for 5 voices total), only Tetra’s four voices will
play when a stacked or split program is selected. In other words, the Mopho
voice will only play in normal keyboard mode.

33

Also, Mopho’s INPUT GAIN (similar to Tetra’s FEEDBACK GAIN) is not
programmable, so it may take some tweaking to get feedback to sound the same
on Mopho and Tetra, even if the same programs are loaded in both. Programs
that don’t use feedback should sound the same.

34

Various Poly Chain Configurations Using

Tetra, Mopho, and the Prophet ’08*

*If Out 4 and Out 8 do not appear as poly chain options on the Prophet, contact
[e-mail] for information about updating the OS.

35

Using USB

Tetra’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. Tetra 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.

Tetra transmits and receives MIDI data via USB, but does not transmit audio.

Note: MIDI In and USB should not be used at the same time, as
overlapping messages from different sources may cause Tetra to respond
unpredictably. MIDI Out and USB can be used at the same time and
transmit the same data. Poly Chain Out is an independent MIDI bus and
can be used regardless of the “normal” MIDI connection.

USB Notes

Under Mac OS X, Tetra will appear as a MIDI port when connected via USB
and can be configured using the Mac’s Audio MIDI Setup application (typically
found in Applications/Utilities).

Under Windows XP, the first time Tetra is connected via USB, the “Found new
hardware” alert appears and Tetra is automatically installed—somewhat
misleadingly—as “USB Audio Device.” If there is already another Class
Compliant USB device installed, Tetra will show up as “USB Audio Device(2)”
(or 3 or 4 or...).

To determine which USB Audio Device is Tetra:

1. Open the System Control Panel

2. Click the Hardware tab.

3. Click Device Manager.

4. Expand “Sound, video, and game controllers.”

5. Right-click any “USB Audio Device” and choose Properties from the

pop-up menu.

The General tab of the USB Audio Device Properties window displays the
Device Type, Manufacturer, and Location. For Tetra, the Location should read
“Location n (DSI Tetra).”

36

Windows Vista essentially behaves the same as XP, but the device name is DSI
Tetra rather than USB Audio Device.

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

37

Modulation Destinations

Display Destination

Off

No destination selected

Osc 1 Freq

Oscillator 1 Frequency

Osc 2 Freq

Oscillator 2 Frequency

OscAllFreq

Oscillator 1 and 2 Frequency

Osc Mix

Oscillator Mix

NoiseLevel

Noise Level

Osc1 PulsW

Oscillator 1 Pulse Width

Osc2 PulsW

Oscillator 2 Pulse Width

Osc All PW

All Oscillators Pulse Width

Low Pass

Lowpass Filter Frequency

Resonance

Resonance

Audio Mod

Audio Mod Amount

VCA Level

VCA Amount

Output Pan

Stereo Pan Position

LFO 1 Freq

LFO 1 Frequency

LFO 2 Freq

LFO 2 Frequency

LFO 3 Freq

LFO 3 Frequency

LFO 4 Freq

LFO 4 Frequency

LFOAllFreq

All LFO Frequencies

LFO 1 Amt

LFO 1 Amount

LFO 2 Amt

LFO 2 Amount

LFO 3 Amt

LFO 3 Amount

LFO 4 Amt

LFO 4 Amount

LFOAll Amt

All LFO Amounts

Env 1 Amt

Envelope 1 Amount (Level)

Env 2 Amt

Envelope 2 Amount (Level)

Env 3 Amt

Envelope 3 Amount (Level)

EnvAll Amt

All Envelope Amounts (Levels)

Env1Attack

Envelope 1 Attack Rate

Env2Attack

Envelope 2 Attack Rate

Env3Attack

Envelope 3 Attack Rate

EnvAll Att

All Envelope Attack Rates

Env1 Decay

Envelope 1 Decay Rate

Env2 Decay

Envelope 2 Decay Rate

Env3 Decay

Envelope 3 Decay Rate

EnvAll Dec

All Envelope Decay Rates

Env1Releas

Envelope 1 Release Rate

Env2Releas

Envelope 2 Release Rate

38

Env3Releas

Envelope 3 Release Rate

EnvAll Rel

All Envelope Release Rates

Mod 1 Amt

Modulator 1 Amount

Mod 2 Amt

Modulator 2 Amount

Mod 3 Amt

Modulator 3 Amount

Mod 4 Amt

Modulator 4 Amount

Fback Vol

Feedback Volume

Sub Osc 1

Sub Oscillator 1 Level

Sub Osc 2

Sub Oscillator 2 Level

Fback Gain

Feedback Gain

39

Modulation Sources

Display Source

Off

No source selected

Sequence1

Sequence 1

Sequence2

Sequence 2

Sequence3

Sequence 3

Sequence4

Sequence 4

LFO 1

LFO 1

LFO 2

LFO 2

LFO 3

LFO 3

LFO 4

LFO 4

Filt Env1

Filter Envelope

VCA Env 2

Amp (VCA) Envelope

Envelope3

Envelope 3

PitchBend

Pitch Bend

Mod Wheel

Mod Wheel

Pressure

Pressure (Aftertouch)

MidBreath

MIDI — Breath Controller

Midi Foot

MIDI — Foot Controller

Midi Exp

MIDI — Expression

Velocity

Keyboard Note Velocity

KeyNumber

Keyboard Note Number

Noise

Noise

40

Parameter List

Osc 1 Frequency
Osc 1 Fine Freq
Oscillator 1 Shape
Oscillator 1 Glide
Osc 1 Key Track
Sub Osc 1 Level
Osc 2 Frequency
Osc 2 Fine Freq
Oscillator 2 Shape
Oscillator 2 Glide
Osc 2 Key Track
Sub Osc 2 Level
Osc Hard Sync
Glide Mode
Oscillator Slop
Pitch Wheel Range
Oscillator Mix
Noise Level
Feedback Volume
Feedback Gain
Filter Cutoff Freq
Filter Resonance
Filter Keyboard Amt
Filter Audio Mod
Filter Config/Mode
Filter Env Amount
Filter Env Velocity
Filter Env Delay
Filter Env Attack
Filter Env Decay
Filter Env Sustain
Filter Env Release
VCA Level
VCA Env Amount
VCA Env Velocity
VCA Env Delay
VCA Env Attack
VCA Env Decay
VCA Env Sustain

VCA Env Release
Pan Spread
Program Volume*
LFO 1 Frequency
LFO 1 Shape
LFO 1 Amount
LFO 1 Destination
LFO 1 Key Sync
LFO 2 Frequency
LFO 2 Shape
LFO 2 Amount
LFO 2 Destination
LFO 2 Key Sync
LFO 3 Frequency
LFO 3 Shape
LFO 3 Amount
LFO 3 Destination
LFO 3 Key Sync
LFO 4 Frequency
LFO 4 Shape
LFO 4 Amount
LFO 4 Destination
LFO 4 Key Sync
Env 3 Destination
Envelope 3 Amount
Envelope 3 Velocity
Envelope 3 Delay
Envelope 3 Attack
Envelope 3 Decay
Envelope 3 Sustain
Envelope 3 Release
Envelope 3 Repeat
Mod 1 Source
Mod 1 Amount
Mod 1 Destination
Mod 2 Source
Mod 2 Amount
Mod 2 Destination
Mod 3 Source

Mod 3 Amount
Mod 3 Destination
Mod 4 Source
Mod 4 Amount
Mod 4 Destination
Mod Wheel Amount
Mod Wheel Dest
Pressure Amount
Pressure Destination
Breath Amount
Breath Destination
Velocity Amount
Velocity Destination
Foot Control Amt
Foot Control Dest
Unison Mode**
Unison Assign
Unison On/Off†
Push It Note
Push It Velocity
Push It Mode
Split Point‡
Key Mode‡
Clock BPM
Clock Divide
Arpeggiator Mode
Arpeggiator On/Off
Sequence Trigger
Sequencer On/Off
Seq 1 Destination
Seq 2 Destination
Seq 3 Destination
Seq 4 Destination
Seq 1 Steps 1 - 16
Seq 2 Steps 1 - 16
Seq 3 Steps 1 - 16
Seq 4 Steps 1 - 16
Edit Name†

*In Combo Mode, voice 1 and 3 only
** Program Mode only; not in Combo Mode
†In Combo Mode, voice 1 only
‡ Program Mode, layer A only

41

MIDI Implementation

Tetra receives MIDI data according to the mode controls under GLOBAL. In
addition, there is interaction between some of the program parameters that
determine the overall response of Tetra to MIDI data. Note that the following
applies to using both the MIDI jacks and USB.

Following are the Global parameters that affect response to MIDI:

MIDI Channel: ALL, 1…16 — Selects the MIDI channel to send and receive

data, 1 to 16. All receives on any channel.

Clock: see table — Selects the MIDI clock status as follows:

Display MIDI Clock Setting

Internal

MIDI clock is neither sent nor received

MIDI Out

MIDI clock is sent

MIDI In

MIDI clock is received

MIDIn/Out

MIDI clock is received and transmitted

MIDI Parameter Send: NRPN, CC, Off — Changes to the values of Tetra’s 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.

MIDI Parameter Receive: All, NRPN, CC, Off — Sets the method by which

Tetra receives parameter changes via MIDI. As with transmission, NRPNs are
the preferred method, though some controllers may only be able to send CCs.

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

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

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

SysEx messages, and will transmit them, when prompted, to the MIDI Out.

MIDI Messages

System Real-time Messages

Status Description

1111 1000 MIDI Timing Clock

42

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” table following

1100 nnnn 0ppppppp Program change, 0-127 for Programs 1-128

within current Bank
1101 nnnn 0vvvvvvv Channel Pressure
1110 nnnn 0vvvvvvv 0vvvvvvv Pitch Bend LS Byte then MS Byte

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

Received Controller Messages

Status Second Third Description

1011 nnnn 1 0vvvvvvv Mod Wheel — directly assignable controller
1011 nnnn 2 0vvvvvvv Breath Controller — directly assignable controller
1011 nnnn 4 0vvvvvvv Foot Controller — directly assignable controller
1011 nnnn 7 0vvvvvvv Volume — Combined with Master Volume and

Voice Volume
1011 nnnn 74 0vvvvvvv Brightness — Added to low-pass filter cutoff

frequency
1011 nnnn 11 0vvvvvvv Expression Controller — directly assignable

controller
1011 nnnn 32 0vvvvvvv Bank Select — 0 -3 select banks 1 – 4; others

ignored
1011 nnnn 64 0vvvvvvv Damper pedal — holds envelopes in Sustain if

0100 0000 or higher
1011 nnnn 123 0vvvvvvv All Notes Off — clear all MIDI notes
1011 nnnn 121 0vvvvvvv Reset All Controllers — clears all MIDI

controllers to 0, 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

1100 nnnn 0ppppppp Program change, 0 — 127 for Programs 1 —

128 within current Bank

43

Transmitted Controller Messages

Status Second Third Description

1011 nnnn 0000 0111 0vvvvvvv Volume knob
1011 nnnn 0010 0000 0vvvvvvv Bank Select — 0 to 2

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

Additional Continuous Controllers

(CCs) Transmitted/Received

The following table details how CCs are mapped onto Tetra’s controls. They are
transmitted when MIDI Parameter Send is set to CC in Global, and recognized
when received when MIDI Parameter Receive is set to either CC or All in
Global.

Parameter CC

OSC 1 FREQ 20
OSC 1 FREQ FINE 21
OSC 1 SHAPE 22
GLIDE 1 23

OSC 2 FREQ 24
OSC 2 FREQ FINE 25
OSC 2 SHAPE 26
GLIDE 2 27

OSC MIX 28
NOISE LEVEL 29

SUB OSC 1 LEVEL 30
SUB OSC 2 LEVEL 31

FEEDBACK VOLUME 52
FEEDBACK GAIN 53

FILTER FREQ 102
RESONANCE 103
FIL KEY AMT 104
FIL AUDIO MOD 105
FILTER ENV AMT 106
FIL ENV VEL AMT 107
FIL DEL 108
FIL ATT 109
FIL DEC 110

FIL SUS 111
FIL REL 112

VCA LEVEL 113
OUTPUT PAN 114
VCA ENV AMOUNT 115
AMP ENV VEL AMT 116
VCA DEL 117
VCA ATT 118
VCA DEC 119
VCA SUS 75
VCA REL 76

ENV3 DEST 85
ENV3 AMT 86
ENV 3 VEL AMT 87
ENV 3 DELAY 88
ENV3 ATT 89
ENV3 DEC 90
ENV3 SUS 77
ENV3 REL 78

TEMPO 14
TIME SIG 15

44

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 either NRPN or All 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-significant bits, and the MSB has the seven most­significant 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.

45

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

parameter number (when both MSB and LSB

received)

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

parameter number (when both MSB and LSB

received)

Global Parameter Data

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

NRPN Range Description

384 0 - 24 Master Transpose: 0= -12 semitones (1 octave), 12=0 (no

transpose), and 24= +12 semitones.

385 0 - 100 Master Fine Tune: 0 = -50 cents, 50 = 0 (centered), 100 = + 50

cents

386 0 - 16 MIDI Channel: if = 0, data received on all MIDI channels.

Otherwise = channel number 1 - 16.

387 0 - 7 Poly Chain*

0 Off
1 Out 1
2 Out 4
3 Out 8
4 Out 12
5 In End
6 InOut4
7 InOut8

388 0 - 3 MIDI Clock Source*

0 Use Internal clock, don’t send MIDI clock
1 Use Internal clock, send MIDI clock
2 Use MIDI clock In
3 Use MIDI clock In, and retransmit MIDI clock out

389 0 - 1 Local Control* Off/On

390 0 - 2 Parameter Send*:

0 NRPN
1 CC
2 Off

46

391 0 - 3

Parameter Receive†:
0 All
1 NRPN only
2 CC only
3 Off

394 0 - 1 MIDI Controller Send/Receive Off/On

395 0 - 1 MIDI Sysex Send/Receive Off/On

400 0 - 3 Audio Out:

0 Stereo
1 Mono
2 Quad
3 Q LR34

403 0 - 13 Balance Tweak*: 0 = -7, 7 = 0, and 13 = 7

404 0 - 2 Pot Mode: Relative, Passthru, Jump

406 0 - 1 MIDI Out Select*:

0 MIDI Out
1 MIDI Thru

407 0 – 1 Multi Mode Off/On

*Received, but not sent.

†Sent, but ignored when received.

Program Parameter Data

The following table lists Tetra’s voice parameters. The parameter number in the
program and edit buffer dumps are different than the NRPN numbers as seen;
this was to maintain NRPN compatibility with the Prophet ’08 as much as
possible.

Parm A B Range Description

0 0 200 0 – 120 Oscillator 1 Frequency, 0 – 120 in

semitones (10 octave range)

1 1 201 0 – 100 Oscillator 1 Fine Tune; 0 = -50 cents, 50

= 0 (centered), 100 = + 50 cents

2 2 202 0-103 Oscillator 1 Shape

0 Oscillator Off
1 Sawtooth
2 Triangle
3 Sawtooth/triangle mix

4 – 103 Pulse Wave, Pulse width 0 – 99
3 3 203 0 - 127 Oscillator 1 Glide
4 4 204 0 - 1 Oscillator 1 Keyboard Off/On
6 5 205 0 – 120 Oscillator 2 Frequency, 0 – 120 in

semitones (10 octave range)
7 6 206 0 – 100 Oscillator 2 Fine Tune; 0 = -50 cents, 50

= 0 (centered), 100 = + 50 cents

47

8 7 207 0-103 Oscillator 2 Shape

0 Oscillator Off

1 Sawtooth

2 Triangle

3 Sawtooth/triangle mix

4 – 103 Pulse Wave, Pulse width 0 – 99
9 8 208 0 - 127 Oscillator 2 Glide

10 9 209 0 - 1 Oscillator 2 Keyboard Off/On
12 10 210 0 - 1 Sync off/on
13 11 211 0 - 3 Glide Mode:

0 fixed rate

1 fixed rate auto

2 fixed time

3 fixed time auto

14 12 212 0 - 5 Oscillator Slop
16 13 213 0 - 127 Oscillator 1 - 2 Mix
17 14 214 0 - 127 Noise Level

20 15 215 0 - 164 Filter Frequency, steps in semitones
21 16 216 0 - 127 Resonance
22 17 217 0 - 127 Filter Keyboard Amount
23 18 218 0 - 127 Filter Audio Modulation
24 19 219 0 - 1 Filter Poles 0: 2-pole; 1: 4-pole
25 20 220 0 - 254 Filter Envelope Amount; -127 to +127
26 21 221 0 - 127 Filter Envelope Velocity Amount
27 22 222 0 - 127 Filter Envelope Delay
28 23 223 0 - 127 Filter Envelope Attack
29 24 224 0 - 127 Filter Envelope Decay
30 25 225 0 - 127 Filter Envelope Sustain
31 26 226 0 - 127 Filter Envelope Release

32 27 227 0 - 127 VCA Initial Level
40 28 228 0 - 127 Output Spread
41 29 229 0 - 127 Voice Volume
33 30 230 0 - 127 VCA Envelope Amount
34 31 231 0 - 127 VCA Envelope Velocity Amount
35 32 232 0 - 127 VCA Envelope Delay
36 33 233 0 - 127 VCA Envelope Attack
37 34 234 0 - 127 VCA Envelope Decay
38 35 235 0 - 127 VCA Envelope Sustain
39 36 236 0 - 127 VCA Envelope Release

48

42 37 237 0 - 166 LFO 1 Frequency; 0 – 150 unsynced

frequencies

151 Sequence speed divided by 32

152 Sequence speed divided by 16

153 Sequence speed divided by 8

154 Sequence speed divided by 6

155 Sequence speed divided by 4

156 Sequence speed divided by 3

157 Sequence speed divided by 2

158 Sequence speed divided by 1.5

159 One cycle per step

160 Two cycles per three steps

161 Two cycles per step

162 One cycles per three steps

163 Four cycles per step

164 Six cycles per step

165 Eight cycles per step

166 Sixteen cycles per step

43 38 238 0 - 4 LFO 1 Shape

0 Triangle

1 Reverse Sawtooth

2 Sawtooth

3 Pulse (square)

4 Random

44 39 239 0 - 127 LFO 1 Amount
45 40 240 0 - 43 LFO 1 Mod Destination; See Modulation

Destination list below

46 41 241 0 - 1 LFO 1 Key Sync Off/On
47 42 242 0 - 166 LFO 2 Frequency; same as LFO 1
48 43 243 0 - 4 LFO 2 Shape; same as LFO 1
49 44 244 0 - 127 LFO 2 Amount
50 45 245 0 - 43 LFO 2 Mod Destination; See Modulation

Destination list below

51 46 246 0 - 1 LFO 2 Key Sync Off/On
52 47 247 0 - 166 LFO 3 Frequency; same as LFO 1
53 48 248 0 - 4 LFO 3 Shape; same as LFO 1
54 49 249 0 - 127 LFO 3 Amount
55 50 250 0 - 43 LFO 3 Mod Destination; See Modulation

Destination list below

56 51 251 0 - 1 LFO 3 Key Sync Off/On
57 52 252 0 - 166 LFO 4 Frequency; same as LFO 1
58 53 253 0 - 4 LFO 4 Shape; same as LFO 1
59 54 254 0 - 127 LFO 4 Amount
60 55 255 0 - 43 LFO 4 Mod Destination; See Modulation

Destination list below

61 56 256 0 - 1 LFO 4 Key Sync Off/On

62 57 257 0 - 43 Envelope 3 Mod Destination; See Mod

Destination list below

63 58 258 0 - 254 Envelope 3 Amount; -127 to +127
64 59 259 0 - 127 Envelope 3 Velocity Amount
65 60 260 0 - 127 Envelope 3 Delay

49

66 61 261 0 - 127 Envelope 3 Attack
67 62 262 0 - 127 Envelope 3 Decay
68 63 263 0 - 127 Envelope 3 Sustain
69 64 264 0 - 127 Envelope 3 Release

71 65 265 0 - 20 Mod 1 Source; See Modulation Source

list below

72 66 266 0 - 254 Mod 1 Amount; -127 to +127
73 67 267 0 - 43 Mod 1 Destination; See Modulation

Destination list below

74 68 268 0 - 20 Mod 2 Source; See Modulation Source

list below

75 69 269 0 - 254 Mod 2 Amount; -127 to +127
76 70 270 0 - 43 Mod 2 Destination; See Modulation

Destination list below

77 71 271 0 - 20 Mod 3 Source; See Modulation Source

list below

78 72 272 0 - 254 Mod3 Amount; -127 to +127
79 73 273 0 - 43 Mod 3 Destination; See Modulation

Destination list below

80 74 274 0 - 20 Mod 4 Source; See Modulation Source

list below

81 75 275 0 - 254 Mod 4 Amount; -127 to +127
82 76 276 0 - 43 Mod 4 Destination; See Modulation

Destination list below

107 77 277 0 - 43 Sequence 1 Destination; See

ModDestination list below

108 78 278 0 - 43 Sequence 2 Destination; See

ModDestination list below

109 79 279 0 - 43 Sequence 3 Destination; See

ModDestination list below

110 80 280 0 - 43 Sequence 4 Destination; See

ModDestination list below

83 81 281 0 - 254 Mod Wheel Amount; -127 to +127
84 82 282 0 - 43 Mod Wheel Destination; See

ModDestination list below

85 83 283 0 - 254 Pressure Amount; -127 to +127
86 84 284 0 - 43 Pressure Destination; See

ModDestination list below

87 85 285 0 - 254 Breath Amount; -127 to +127
88 86 286 0 - 43 Breath Destination; See ModDestination

list below

89 87 287 0 - 254 Velocity Amount; -127 to +127
90 88 288 0 - 43 Velocity Destination; See

ModDestination list below

91 89 289 0 - 254 Foot Control Amount; -127 to +127
92 90 290 0 - 43 Foot Control Destination; See

ModDestination list below

50

101 91 291 30 - 250 BPM tempo
102 92 292 0 - 12 Clock Divide:

Half Note

Quarter Note

Eighth Note

Eighth Note half swing

Eighth Note full swing

Eighth Note triplets

Sixteenth Note

Sixteenth Note half swing

Sixteenth Note full swing

Sixteenth Note triplets

Thirty-second Notes

Thirty-second Notes triplets

Sixty-Fourth note triplets

15 93 293 0 - 12 Pitch Bend Range

105 94 294 0 - 4 Sequencer Trigger:

0 Normal

1 Normal, no reset

2 No gate

3 No gate/no reset

4 key step

94 95 295 0 - 5 Key Mode:

0 Low note priority

1 Low note priority with re-trigger

2 High note priority

3 High note priority with re-trigger

4 Last note hit priority

5 Last note hit priority with re-trigger

93 96 296 0 - 4 Unison Mode:

0 1 voice

1 All voices

2 All voices detune1

3 All voices detune2

4 All voices detune3

103 97 297 0 - 3 Arpeggiator Mode:

0 Up

1 Down

2 Up/Down,

3 Assign

70 98 298 0 - 1 Envelope 3 Repear Mode; off/on

95 99 299 0 - 1 Unison; off/on
104 100 300 0 - 1 Arpeggiator; off/on
106 101 301 0 - 1 Gated Sequencer; off/on

111 105 X 0 - 183 Assignable Parameter 1

112 106 X 0 - 183 Assignable Parameter 2

113 107 X 0 - 183 Assignable Parameter 3

114 108 X 0 - 183 Assignable Parameter 4

19 110 310 0 - 127 Feedback Gain

51

96 111 311 0 - 127 Push It Note: C0 to C10

97 112 312 0 - 127 Push It Velocity

98 113 313 0 - 1 Push It Mode: Normal, Toggle

5 114 314 0 - 127 Sub Oscillator 1 Level

11 115 315 0 - 127 Sub Oscillator 2 Level

18 116 316 0 - 127 Feeback Volume

117 117 X Editor Byte

99 118 X 0 - 127 Split Point; 60 = C3

100 119 X 0 - 2 Keyboard Mode:

Normal
Stack
Split

120 120-135 320-335 0 - 127 Sequence Track1, steps 1 – 16

0 to 125: Normal sequence step value
126 Reset
127 Rest

136 136-151 336-351 0 - 126 Sequence Track 2, steps 1 – 16

0 to 125: Normal sequence step value
126 Reset

152 152-167 352-367 0 - 126 Sequence Track 3, steps 1 – 16

0 to 125: Normal sequence step value
126 Reset

168 168-183 368-383 0 - 126 Sequence Track 4, steps 1 – 16

0 to 125: Normal sequence step value
126 Reset

184 184-199 X 32 - 127 Name charaters 1 – 16, in ASCII

format

52

The following tables list the values used with the program parameters to specify
modulation destinations and sources.

Mod Destinations Value

Off 0
Osc 1 Freq 1

Osc 2 Freq 2
Osc 1 and 2 Freq 3

Osc Mix 4
Noise Level 5

Osc 1 Pulse Width 6
Osc 2 Pulse Width 7

Osc 1 and 2 Pulse Width 8
Filter Frequency 9

Resonance 10
Filter Audio Mod Amt 11

VCA Level 12
Pan Spread 13

LFO 1 Freq 14
LFO 2 Freq 15

LFO 3 Freq 16
LFO 4 Freq 17

All LFO Freq 18
LFO 1 Amt 19

LFO 2 Amt 20
LFO 3 Amt 21

LFO 3 Amt 22
All LFO Amt 23

Filter Env Amt 24
Amp Env Amt 25

Env 3 Amt 26
All Env Amounts 27

Env 1 Attack 28
Env 2 Attack 29

Env 3 Attack 30
All Env Attacks 31

Env 1 Decay 32
Env 2 Decay 33

Env 3 Decay 34
All Env Decays 35

Env 1 Release 36
Env 2 Release 37

Env 3 Release 38
All Env Releases 39

Mod 1 Amt 40
Mod 2 Amt 41

Mod 3 Amt 42
Mod 4 Amt 43

Feedback Volume 44
Sub Osc 1 Level 45

Sub Osc 2 Level 46
Feedback Gain 47

Mod Sources Value

Off 0
Sequence Track 1 1

Sequence Track 2 2
Sequence Track 3 3

Sequence Track 4 4
LFO 1 5

LFO 2 6
LFO 3 7

LFO 4 8
Filter Envelope 9

Amp Envelope 10
Envelope 3 11

Pitch Bend 12
Mod Wheel 13

Pressure 14
MIDI Breath 15

MIDI Foot 16
MIDI Expression 17

Velocity 18
Note Number 19

Noise 20

Combo Parameter Data

Combo Mode has its own set of NRPNs that enable the parameters for each of
the combo’s parts to be addressed on one global MIDI channel. Ranges are the
same as for the previously listed program parameters.

Note: In Multi Mode, the regular, program NRPNs are received and
transmitted for each of the four voices on their separate MIDI channels.

53

Quad NRPNs come from/go to all four voices in a combo.

Parm Parameter 1 2 3 4 Quad

0 OSC 1 FREQ 512 768 1024 1280 1536
1 OSC 1 FREQ

FINE

513 769 1025 1281 1537

2 OSC 1 SHAPE 514 770 1026 1282 1538
3 GLIDE 1 515 771 1027 1283 1539
4 OSC 1 KEY 516 772 1028 1284 1540
6 OSC 2 FREQ 517 773 1029 1285 1541
7 OSC 2 FREQ

FINE

518 774 1030 1286 1542

8 OSC 2 SHAPE 519 775 1031 1287 1543
9 GLIDE 2 520 776 1032 1288 1544
10 OSC 2 KEY 521 777 1033 1289 1545
12 SYNC 522 778 1034 1290 1546
13 GLIDE MODE 523 779 1035 1291 1547
14 OSC SLOP 524 780 1036 1292 1548
16 OSC MIX 525 781 1037 1293 1549
17 NOISE LEVEL 526 782 1038 1294 1550

20 FILTER FREQ 527 783 1039 1295 1551
21 RESONANCE 528 784 1040 1296 1552
22 FIL KEY AMT 529 785 1041 1297 1553
23 FIL AUDIO MOD 530 786 1042 1298 1554
24 FILTER POLES 531 787 1043 1299 1555
25 FILTER ENV

AMT

532 788 1044 1300 1556

26 FIL ENV VEL

AMT

533 789 1045 1301 1557

27 FIL DEL 534 790 1046 1302 1558
28 FIL ATT 535 791 1047 1303 1559
29 FIL DEC 536 792 1048 1304 1560
30 FIL SUS 537 793 1049 1305 1561
31 FIL REL 538 794 1050 1306 1562

32 VCA LEVEL 539 795 1051 1307 1563
40 OUTPUT PAN 540 796 1052 1308 1564
41 PRESET

VOLUME

541
(A)

X 1053

(B)

X X

33 VCA ENV

AMOUNT

542 798 1054 1310 1566

34 VCA ENV VEL

AMT

543 799 1055 1311 1567

35 VCA DEL 544 800 1056 1312 1568
36 VCA ATT 545 801 1057 1313 1569

54

37 VCA DEC 546 802 1058 1314 1570
38 VCA SUS 547 803 1059 1315 1571
39 VCA REL 548 804 1060 1316 1572

42 LFO 1 FREQ 549 805 1061 1317 1573
43 LFO 1 SHAPE 550 806 1062 1318 1574
44 LFO 1 AMT 551 807 1063 1319 1575
45 LFO 1 DEST 552 808 1064 1320 1576
46 LFO 1 SYNC 553 809 1065 1321 1577
47 LFO 2 FREQ 554 810 1066 1322 1578
48 LFO 2 SHAPE 555 811 1067 1323 1579
49 LFO 2 AMT 556 812 1068 1324 1580
50 LFO 2 DEST 557 813 1069 1325 1581
51 LFO 2 SYNC 558 814 1070 1326 1582
52 LFO 3 FREQ 559 815 1071 1327 1583
53 LFO 3 SHAPE 560 816 1072 1328 1584
54 LFO 3 AMT 561 817 1073 1329 1585
55 LFO 3 DEST 562 818 1074 1330 1586
56 LFO 3 SYNC 563 819 1075 1331 1587
57 LFO 4 FREQ 564 820 1076 1332 1588
58 LFO 4 SHAPE 565 821 1077 1333 1589
59 LFO 4 AMT 566 822 1078 1334 1590
60 LFO 4 DEST 567 823 1079 1335 1591
61 LFO 4 SYNC 568 824 1080 1336 1592

62 ENV3 DEST 569 825 1081 1337 1593
63 ENV3 AMT 570 826 1082 1338 1594
64 ENV 3 VEL AMT 571 827 1083 1339 1595
65 ENV 3 DELAY 572 828 1084 1340 1596
66 ENV3 ATT 573 829 1085 1341 1597
67 ENV3 DEC 574 830 1086 1342 1598
68 ENV3 SUS 575 831 1087 1343 1599
69 ENV3 REL 576 832 1088 1344 1600

71 MOD SOURCE 1 577 833 1089 1345 1601
72 MOD AMT 1 578 834 1090 1346 1602
73 MOD DEST 1 579 835 1091 1347 1603
74 MOD SOURCE 2 580 836 1092 1348 1604
75 MOD AMT 2 581 837 1093 1349 1605
76 MOD DEST 2 582 838 1094 1350 1606
77 MOD SOURCE 3 583 839 1095 1351 1607
78 MOD AMT 3 584 840 1096 1352 1608
79 MOD DEST 3 585 841 1097 1353 1609
80 MOD SOURCE 4 586 842 1098 1354 1610

55

81 MOD AMT 4 587 843 1099 1355 1611
82 MOD DEST 4 588 844 1100 1356 1612

107 SEQ 1 DEST 589 845 1101 1357 1613
108 SEQ 2 DEST 590 846 1102 1358 1614
109 SEQ 3 DEST 591 847 1103 1359 1615
110 SEQ 4 DEST 592 848 1104 1360 1616

83 MOD WHEEL

AMT

593 849 1105 1361 1617

84 MOD WHEEL

DEST

594 850 1106 1362 1618

85 PRESSURE AMT 595 851 1107 1363 1619
86 PRESSURE

DEST

596 852 1108 1364 1620

87 BREATH AMT 597 853 1109 1365 1621
88 BREATH DEST 598 854 1110 1366 1622
89 VELOCITY AMT 599 855 1111 1367 1623
90 VELOCITY DEST 600 856 1112 1368 1624
91 FOOT AMT 601 857 1113 1369 1625
92 FOOT DEST 602 858 1114 1370 1626

101 TEMPO 603 859 1115 1371 1627
102 TIME SIG 604 860 1116 1372 1628
15 PBEND RANGE 605 861 1117 1373 1629
105 SEQ TRIGGER 606 862 1118 1374 1630
93 UNISON MODE 607 X X X X
94 UNISON

ASSIGN

608 864 1120 1376 1632

97 ARP MODE 609 X X X X
70 REPEAT MODE 610 866 1122 1378 1634
95 UNISON ON

OFF

611 867 1123 1379 1635

104 ARP ON OFF 612 X X X X
106 SEQ ON OFF 613 869 1125 1381 1637

111 PARAM ENC

SEL V1

617 X X X X

112 PARAM ENC

SEL V2

618 X X X X

113 PARAM ENC

SEL V3

619 X X X X

114 PARAM ENC

SEL V4

620 X X X X

19 FEEDBACK 622 878 1134 1390 1646

56

GAIN
96 PUSH IT NOTE 623 879 1135 1391 1647
97 PUSH IT

VELOCITY

624 880 1136 1392 1648

98 PUSH IT MODE 625 881 1137 1393 1649
5 SUB OSC 1 VOL 626 882 1138 1394 1650
11 SUB OSC 2 VOL 627 883 1139 1395 1651
18 FEEDBACK VOL 628 884 1140 1396 1652

117 EDITOR BYTE 629

120 SEQ 1 632 –

647

888 –
903

1144 –
1159

1400 –
1415

1656 –
1671

136 SEQ 2 648 –

663

904 –
919

1160 –
1175

1416 –
1431

1672 –
1687

152 SEQ 3 664 –

679

920 –
935

1176 –
1191

1432 –
1447

1688 –
1703

168 SEQ 4 680 –

695

936 –
951

1192 –
1207

1448 –
1463

1704 –
1719

COMBO NAME 696 –

712

X X X X

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 responds if 0vvvvvvv = 0111 1111.
0000 0110 Inquiry Message
0000 0001 Inquiry Request
1111 0111 End of Exclusive (EOX)

Tetra responds with:

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 0-15.
0000 0110 Inquiry Message
0000 0010 Inquiry Reply

57

0000 0001 DSI ID
0010 0110 Tetra 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
0000 0000 Zero Byte
0000 0000 Zero Byte
1111 0111 End of Exclusive (EOX)

Request Program Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0000 0101 Request Program Transmit

0000 00vv Bank Number, 0 — 1

0vvv vvvv Program Number, 0 — 127

1111 0111 End of Exclusive (EOX)

Tetra 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 0110 Tetra ID

0000 0110 Request Program Edit Buffer Transmit

1111 0111 End of Exclusive (EOX)

Tetra will respond by sending out the current Program edit buffer in the format
described below in Program Edit Buffer Data Dump.

58

Request Global Parameter Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0000 1110 Request Global Parameter Transmit

1111 0111 End of Exclusive (EOX)

Tetra will respond by sending out the current values of Global Parameters in the
format described below in Global Parameters Data Dump.

Request Combo Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0010 0001 Request Combo Transmit

0vvv vvvv Combo Number, 0 - 127

1111 0111 End of Exclusive (EOX)

Tetra will respond by sending out the Combo Data in the format described
below in Combo Data Dump.

Request Combo Edit Buffer Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0011 1000 Request Combo Edit Buffer Transmit

1111 0111 End of Exclusive (EOX)

Tetra will respond by sending out the Combo Data in the format described
below in Combo Edit Buffer Data Dump.

59

Program Data Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0000 0010 Program Data

0000 00vv Bank Number, 0 - 3

0vvv vvvv Program Number, 0 - 127

0vvv vvvv 384 bytes expanded to 446 MIDI bytes in “packed MS bit” format

(see page 60.)

1111 0111 End of Exclusive (EOX)

Program Edit Buffer Data Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0000 0011 Edit Buffer Data

0vvv vvvv 384 bytes expanded to 446 MIDI bytes in “packed MS bit” format

(see page 60.)

1111 0111 End of Exclusive (EOX)

Combo Data Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0010 0010 Combo Data

0vvv vvvv Combo Number, 0 - 127

0vvv vvvv 1024 bytes expanded to 1177 MIDI bytes in “packed MS bit” format

(see page 60.)

1111 0111 End of Exclusive (EOX)

60

Combo Edit Buffer Data Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0011 0111 Edit Buffer Data

0vvv vvvv 1024 bytes expanded to 1177 MIDI bytes in “packed MS bit” format

(see page 60.)

1111 0111 End of Exclusive (EOX)

Global Parameters Data Dump

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0000 1111 Main Parameter Data

0vvv vvvv 20 nibbles (LS then MS) for 10 Global parameters. Global

Parameters are listed starting on page 45.

1111 0111 End of Exclusive (EOX)

Note: The Global Parameters Data Dump is not recognized when received; it is
only transmitted when requested. NRPN messages are used to change Globals.

Mode Change: Program Mode

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0011 0000 Select Program Mode

1111 0111 End of Exclusive (EOX)

61

Mode Change: Combo Mode

Status Description

1111 0000 System Exclusive (SysEx)

0000 0001 DSI ID

0010 0110 Tetra ID

0011 0001 Select Combo Mode

1111 0111 End of Exclusive (EOX)

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 293 MIDI bytes to transmit 256 Program data bytes.

62

Hidden Functions

Hold the ASSIGN PARAMETER switch and hit the Mode switch to calibrate the
low-pass filter and analog oscillator waveshapes. This should not be necessary
for normal operation.

Dave Smith Instruments

1210 Cabrillo Hwy N

Half Moon Bay, CA 94019-1449

USA

www.DaveSmithInstruments.com