Page 1: Buttons
CYCLE I NSTR UME N TS TETRACHORDS M A NUA L UP DAT ED 1 2 /2 /2 4...
Page 2: Table Of Contents
Note Patterns Rotary Encoder / Scale Shift Scale recipes Pivot Modulation Overview Recommended approach Buttons 1 - 4 Buttons 5 - 8 Patterns Overview Display Copying Arrow button switching CV switching Button switching TETRACHORDS | USER GUIDE PAGE | 2...
Page 3 Inversion knob Spread Overview Detail Arp / Chord Path Overview Description Random Path Configuration Reverse Chromatic Overview Two active notes Three active notes Four active notes Keyboard Mode Step Sequencer Overview Description Reset TETRACHORDS | USER GUIDE PAGE | 3...
Page 4 Midi to CV All-Tracks Trigger Channel Overview Channel Configuration MIDI Output Overview Channel Configuration Overview MIDI Velocity Arp velocity Chord velocity Random velocity MIDI Velocity Spread MIDI CC Knobs Overview Example Patch Encoder Overview TETRACHORDS | USER GUIDE PAGE | 4...
Page 5: Buttons
Saving Initialising Progressions Overview Physical Connection Tetrachords Configuration Disting Ex Overview & Setup #14 Quad Envelope #19 Macro Oscillator #20 Resonator #21 Macro Oscillator 2 #23 Poly FM Just Friends Overview & Setup TETRACHORDS | USER GUIDE PAGE | 5...
Page 6 Overview Delay and Synchronize Changes Edit patterns that aren’t playing Firmware Update Config Text File FAQ / Troubleshooting Appendices 1 - Track Input Response Trig In response graph MIDI In response graph Acknowledgements TETRACHORDS | USER GUIDE PAGE | 6...
Page 7 TETRACHORDS | USER GUIDE PAGE | 7...
Page 8: Reading This Guide
The hope is that the overview sections will be sufficient for players who prefer to learn with minimal guidance whilst extra detail is available for those who want it. TETRACHORDS | USER GUIDE PAGE | 8...
Page 9: Before You Start
It requires a standard Eurorack power supply, takes 36hp of rack space and requires instruments to connect to. The Tetrachords outputs MIDI notes and 4 channels of CV but on its own does not generate sounds. TETRACHORDS | USER GUIDE...
Page 10: Getting Started
It is reccomended to check out these videos as they are a quick way of learning the basics of the module. The Tetrachords has some key combos and menus that require a small amount of learning. To assist in learning these, there is a Tips and Menus booklet available.
Page 11: 1St Patch Cv
I N S T R U M E N T S I N S T R U M E N T S T E T R A C H T E T R A C H R D S R D S TETRACHORDS | USER GUIDE PAGE | 11...
Page 12: 1St Patch Midi
I N S T R U M E N T S I N S T R U M E N T S T E T R A C H T E T R A C H R D S R D S TETRACHORDS | USER GUIDE PAGE | 12...
Page 13: Tuning Mode
RESET Abort calibration RGB BUTTONS LED RING Load/Select Tuner display/ LEFT (OR RIGHT) BUTTON calibration calibration progress Begin calibration setting. indicator Pressing SHIFT + LINK / places the Tetrachords in TUNING MODE. TETRACHORDS | USER GUIDE PAGE | 13...
Page 14: Tuner
CV controlled oscillators in tune with MIDI instruments and with each other. To use the tuner, first connect any of the Tetrachords CV OUTS to an oscillator’s v/octave input. Then connect an oscillator output to TRIG IN 1.
Page 15 MIDI note 60. The LED ring indicates the tuning of the oscillator connected to TRIG IN 1. The LED ring tuning display mimics common instrument tuners. See details on the following page. (cont.) TETRACHORDS | USER GUIDE PAGE | 15...
Page 16 LED RING TUNER DISPLAY (less than 261.6Hz) Slightly low (slightly less than 261.6Hz) ‘In Tune’ 261.6Hz Slightly high (slightly greater than 261.6Hz) High (greater than 261.6Hz) (cont.) TETRACHORDS | USER GUIDE PAGE | 16...
Page 17: Troubleshooting Tuning
Troubleshooting tuning The Tetrachords tuner works best with simple waveforms. Where possible use a square wave. Otherwise basic waveforms such as saw, triangle and sine waves can work well. The tuner may not work with more complex waveforms, though by all means try.
Page 18: Calibration
Calibration The Tetrachords is capable of calibrating its CV OUTS to individual oscillators. This can significantly improve how in-tune oscillators will play when sequenced by the Tetrachords, especially for sequences with a wide pitch range. The calibration process currently takes between 1 to 2 minutes.
Page 19: Loading Calibrations
Here LED pills 1 - 5 are illuminated, indicating that calibrations have been saved in slots 1 - 5. Pressing buttons 1 - 5 will load the corresponding saved calibration setting. (cont.) TETRACHORDS | USER GUIDE PAGE | 19...
Page 20: Saving Calibrations
CV OUT you wish to use for the calibration e.g. press TRACK 1 if calibrating CV OUT 1 Connect the selected CV OUT to an oscillator’s v/octave input. Connect the oscillator’s output to TRIG IN 1. (cont.) TETRACHORDS | USER GUIDE PAGE | 20...
Page 21 Press one of RGB buttons 1 - 8 to select where the calibration is to be saved. The LED pill above the button will flash, indicating the slot where the calibration is to be saved. (cont.) TETRACHORDS | USER GUIDE PAGE | 21...
Page 22 No changes to calibration files or settings will be made if calibration is aborted. When calibration is complete, exit Tuning Mode by pressing the LINK / button. TETRACHORDS | USER GUIDE PAGE | 22...
Page 23: Overview
T E T R A C H R D S R D S PATTERN (HOLD) + ROTARY ENCODER (TURN) BUTTON Sets the root note of the Sets the interval scale. between Tetrachord 1 & Tetrachord 2 TETRACHORDS | USER GUIDE PAGE | 23...
Page 24: Scales 1
Notes active in the current scale are illuminated and notes outside the current scale are not. Here the LED ring displays a major scale, with notes 1, 2, 3, 4, 5, 6 & 7 active. TETRACHORDS | USER GUIDE PAGE | 24...
Page 25: Root Note
B and second name minor. The technical term for a scale’s first name is root note. To adjust the root note on the Tetrachords, HOLD PATTERN, then turn the ROTARY ENCODER. There are 12 root note options, visually represented by the 12 LEDs surrounding the ROTARY ENCODER.
Page 26: Tetrachords
A musical scale can be divided into two, four note halves, called tetrachords. This idea inspired the layout of the Tetrachords with the centre of the module being divided into two sections. The TETRACHORD 1 section, for controlling scale notes 1 - 4...
Page 27: Note Patterns
Their second name is derived from the characteristic pattern of intervals, aka musical distances, between each note. Three of the panel controls on the Tetrachords module define the pattern of intervals for a scale. The first half of the scale is set by the TETRACHORD 1 KNOB.
Page 28 Observe that in some of the above examples, note 1 follows note 7. This is a feature of musical scales, after their final note, they begin again on their first note (though one octave higher). (cont.) TETRACHORDS | USER GUIDE PAGE | 28...
Page 29 Note: The Tetrachord 1 Lydian setting has no effect when 5 5 4 is set to 4. The Tetrachord 2 Lydian setting has no effect when 5 5 4 is set to 5. TETRACHORDS | USER GUIDE PAGE | 29...
Page 30: Rotary Encoder / Scale Shift
If the Rotary Encoder is turned one step clock-wise, note 2 of the LED ring is coloured, indicating that RGB button 1 now corresponds to scale note 2. Again, subsequent RGB buttons correspond to subsequent scale notes. (cont.) TETRACHORDS | USER GUIDE PAGE | 30...
Page 31 As an example, the seven possible encoder settings for the natural minor scale are illustrated below. Theoretical note: these settings correspond to what are known as the 7 modes of the natural minor scale. (cont.) TETRACHORDS | USER GUIDE PAGE | 31...
Page 32 (cont.) TETRACHORDS | USER GUIDE PAGE | 32...
Page 33 Turning the encoder clock-wise after the 7th setting results in a return to the original setting, though with all notes shifted 1 octave higher. TETRACHORDS | USER GUIDE PAGE | 33...
Page 34: Scale Recipes
Scales 6 - Scale recipes SCALE TETRACHORD 1 TETRACHORD 2 Major Natural Minor Harmonic Minor Half-Whole Diminished Blues (ish) Phrygian Dominant (cont.) TETRACHORDS | USER GUIDE PAGE | 34...
Page 35 SCALE TETRACHORD 1 TETRACHORD 2 Dorian Mode Phrygian mode Lydian Mode Myxolydian Mode Locrian Mode Whole Tone TETRACHORDS | USER GUIDE PAGE | 35...
Page 36 Minor 3rd down Minor 3rd up Major 3rd up RGB BUTTONS 5-8 Modulate the tonal center up or down a third and change the scale according to which of RGB buttons 1-4 is active. (cont.) TETRACHORDS | USER GUIDE PAGE | 36...
Page 37: Pivot Modulation
Root Note C Musical Mode 3 When the root note is a C, note 3 in the LED RING is an E. This note corresonds with RGB button 1. This is an E (cont.) TETRACHORDS | USER GUIDE PAGE | 37...
Page 38 PIVOT MODULATION using RGB BUTTONS 1 to 4. Note that after these PIVOTS, RGB BUTTON 1 plays the same note. BEFORE MUSICAL MODE 3 ROOT NOTE C This is an E TETRACHORDS | USER GUIDE PAGE | 38...
Page 39 BUTTON PRESSED MUSICAL MODE 1 ROOT NOTE E RGB BUTTON 1 | major RGB BUTTON 2 | minor RGB BUTTON 3 | diminished RGB BUTTON 4 | whole-tone This is still an E (cont.) TETRACHORDS | USER GUIDE PAGE | 39...
Page 40 The root note changes, as illustrated below. Down Down Maj 3 Min 3 Min 3 Maj 3 Set the musical mode to musical mode 1. This works the same as for buttons 1 - 4. TETRACHORDS | USER GUIDE PAGE | 40...
Page 41: Overview
The LEFT and RIGHT buttons navigate between active patterns. Hold PATTERN then press an RGB button to select a PATTERN. Sending a trigger to MOD 6 switches to the next active PATTERN. This is equivalent to pressing the RIGHT button. TETRACHORDS | USER GUIDE PAGE | 41...
Page 42: Patterns
A dark pill indicates an inactive PATTERN. By default, PATTERN 1 is playing and is the only active PATTERN. In the example below, PATTERN 1 is playing and PATTERNS 2 & 4 are active. TETRACHORDS | USER GUIDE PAGE | 42...
Page 43: Copying
RIGHT button copies PATTERN 1 to PATTERN 2. Note that PATTERN 2 is now playing. Press and hold the PATTERN button and then press the LEFT ARROW button to copy the playing PATTERN to the previous PATTERN. TETRACHORDS | USER GUIDE PAGE | 43...
Page 44: Arrow Button Switching
... the first active PATTERN becomes the playing PATTERN. Conversely, if the first active PATTERN is the control PATTERN and the LEFT ARROW button is pressed..the last active PATTERN becomes the playing PATTERN. (cont.) TETRACHORDS | USER GUIDE PAGE | 44...
Page 45: Cv Switching
Path settings Scale settings Octave settings Spread settings Inversion settings Arp/Chord settings Chromatic settings Reverse settings Active note settings i.e. which notes play Custom pattern settings MIDI CC settings MIDI velocity settings LFO settings TETRACHORDS | USER GUIDE PAGE | 45...
Page 46 Tracks The Tetrachords features 4 polyphonic tracks with fixed CV inputs, assignable MIDI inputs and assignable CV and MIDI outputs. TRIG INS Assigned to tracks 1-4 CV OUTS respectively. Assigned by default to TRACK BUTTONS Select the active track. tracks 1-4 respectively MIDI INPUTS &...
Page 47: Triggering
Tracks Triggering Notes on the Tetrachords can be triggered by an external CV or MIDI connection. MIDI input connections are made Trig In connections 1 - 4 are used by USB or by the MIDI IN jack. to trigger tracks 1 - 4 respectively.
Page 48: Outputs
The MIDI OUT jack works with Type A (Korg) MIDI jack connectors by default. A switch is located on the bottom PCB of the Tetrachords to switch the MIDI OUT to Type B. By default, tracks 1 - 4 send MIDI note messages on channels 1 - 4 respectively.
Page 49: Link
Whether or not TRACKS will always play the same PATTERN as each other. WHAT IT MEANS FOR TRACKS TO ‘PLAY THE SAME SCALE’ On the Tetrachords, TRACKS having the same scale settings, means that the following 5 settings will be identical.
Page 50: Tracks
TRACK 1 T E T R A C H R D S NOTE: it isn’t possible to change the LINK setting of TRACK 1 which, by definition, is always linked to itself. (cont.) TETRACHORDS | USER GUIDE PAGE | 50...
Page 51 Experimenting with polytonality by stacking progressions in different keys. Starting with a sequence created with the TRACK 1 LINK setting then using the ENCODER to make it sound a little less locked-in and predictable. (cont.) TETRACHORDS | USER GUIDE PAGE | 51...
Page 52 TRACK with LINK set to TRACK 1 or HALF. This is analagous to musicians agreeing to always use notes from the same scale and to always change chords together at the same time. TETRACHORDS | USER GUIDE PAGE | 52...
Page 53: Octaves
Turning the rotary encoder, whilst the octave button is pressed, also changes the track octave setting. A clockwise turn increments the octave setting, an anti-clockwise setting decrements it. TETRACHORDS | USER GUIDE PAGE | 53...
Page 54: Overview
Similarly, pressing shift and turning the encoder counter-clockwise causes the highest active notes to be lowered one octave. Continuously turning the encoder counter- clockwise results in notes cascading downwards until they reach their lower limit TETRACHORDS | USER GUIDE PAGE | 54...
Page 55: Inversion Knob
DROP 3 Notes 3 and 4 are lowered by 1 octave. DROP 2 Notes 5 and 6 are lowered by 1 octave. DROP 1 Notes 7 and 8 are lowered by 1 octave. (cont.) TETRACHORDS | USER GUIDE PAGE | 55...
Page 56 Notes 1 and 2 are raised by 1 octave. Notes 1, 2, 3 and 4 are raised by 1 octave. Notes 1, 2, 3, 4, 5 and 6 are raised by 1 octave. TETRACHORDS | USER GUIDE PAGE | 56...
Page 57 THEORETICAL DISCLAIMER (safe to ignore for everyone - possibly interesting to those familiar with inversions and associated terminology) The Tetrachords implementation of inversions does not align 100% with established practice. This is for pragmatic reasons, to make the INVERSION knob more useful and fun.
Page 58: Overview
LEDs above the knob. When turned clockwise, the AMOUNT knob shifts selected notes up by 1 to 3 octaves. When turned counter-clockwise, the AMOUNT knob shifts selected notes down by 1 to 3 octaves. TETRACHORDS | USER GUIDE PAGE | 58...
Page 59: Detail
Turning the AMOUNT knob counter- clockwise lowers notes by 1 to 3 octaves. In this setting, notes at the beginning of the SETTING 2 tetrachord will always be higher than those at the end. (cont.) TETRACHORDS | USER GUIDE PAGE | 59...
Page 60 In this setting, the amount knob affects SETTING 3 only the 1st and 3rd notes of the tetrachord. In this setting, the amount knob affects SETTING 4 only the 2nd and 4th notes of the tetrachord. (cont.) TETRACHORDS | USER GUIDE PAGE | 60...
Page 61 In this setting, the amount knob affects SETTING 5 only the middle notes of the tetrachord. In this section, the amount knob affects SETTING 6 only the outer notes of the tetrachord. TETRACHORDS | USER GUIDE PAGE | 61...
Page 62: Arp / Chord
13 notes. The Tetrachords module can easily transmit 13 note chords via MIDI, however it is limited to a maximum of 4 simultaneous notes via CV.
Page 63: Overview
Pressing an RGB note button, results in a note being added to, or removed from, the current pattern. The order in which a pattern’s notes play is determined by the position of the PATH knob. TETRACHORDS | USER GUIDE PAGE | 63...
Page 64: Path
The various path settings are described on the following pages. In the descriptions, note order refers to order in which the RGB note buttons are triggered. The buttons are referred to by number as illustrated below. (cont.) TETRACHORDS | USER GUIDE PAGE | 64...
Page 65 1 - 3 - 2 - 4 PATH 4 5 - 7 - 6 - 8 PATH 5 1 - 5 - 2 - 7 4 - 8 - 3 - 6 (cont.) TETRACHORDS | USER GUIDE PAGE | 65...
Page 66 5-note loop, consisting of some random combination of the currently active notes. In the default loop, active notes may be repeated or omitted. Press the random button once to re-randomise the pattern. (cont.) TETRACHORDS | USER GUIDE PAGE | 66...
Page 67: Random Path Configuration
In this case, the length of the loop is equal to the number of active notes. TETRACHORDS | USER GUIDE PAGE | 67...
Page 68: Reverse
Each tetrachord section features a reverse button, labelled REV. The reverse button reverses the order in which any active notes in the corresponding tetrachord are played. The LED above the button illuminates when reverse is engaged. TETRACHORDS | USER GUIDE PAGE | 68...
Page 69: Overview
The chromatic button affects a pattern differently depending on the how many notes are active in the corresponding tetrachord. The way this works is detailed on the following pages. TETRACHORDS | USER GUIDE PAGE | 69...
Page 70: Two Active Notes
Scale notes 1 & 2 are now part of the current sequence. Press the chromatic button The 2 note i.e. the note between scale notes 1 & 2, is now part of the sequence also. (cont.) TETRACHORDS | USER GUIDE PAGE | 70...
Page 71: Three Active Notes
Scale notes 1, 2 & 5 are now part of the current sequence. Press the chromatic button The 2 note i.e. the note between scale notes 1 & 2, is now part of the sequence also. (cont.) TETRACHORDS | USER GUIDE PAGE | 71...
Page 72: Four Active Notes
The 2 note i.e. the note between scale notes 1 & 2, is now part of the sequence. The 4 note i.e. the note between scale notes 3 & 5, is now part of the sequence. TETRACHORDS | USER GUIDE PAGE | 72...
Page 73: Keyboard Mode
KEYBOARD MODE has been engaged. In KEYBOARD MODE, the RGB buttons can be triggered manually by pressing them. To exit KEYBOARD MODE, press the STEP SEQ button again (with or without the SHIFT button). TETRACHORDS | USER GUIDE PAGE | 73...
Page 74: Step Sequencer
STEP SEQ button is held the point at which notes will be clears the current sequence added to or removed from the and starts a new one. sequence. TETRACHORDS | USER GUIDE PAGE | 74...
Page 75: Description
32 notes. It works similarly to classic step-time sequencers such as found on the Roland SH-101. In regular Tetrachords operation, the order of notes is determined by the PATH knob, which selects one of the 6 pre-defined note patterns, or a randomised pattern.
Page 76 BACK button to clear a single note from the custom path. STEP SEQUENCER LED RING DISPLAY When the STEP SEQ button is pressed, the RGB LED ring and the white LED PILLS display the seqeunce length (cont.) TETRACHORDS | USER GUIDE PAGE | 76...
Page 77: Reset
The RESET button is also used as a utility function for Initialising and clearing. Go to the Utility Buttons section for a full rundown of how RESET is used as a utility function. TETRACHORDS | USER GUIDE PAGE | 77...
Page 78 The idea of JAM mode is to make it more likely that notes will stay in the same octave register when changing PATTERNS. This can make it easier to stay, ‘in the moment’, when jamming on PATTERN changes. TETRACHORDS | USER GUIDE PAGE | 78...
Page 79 (so they have no effect). Use the INVERSION and OCTAVE settings to make the sequence flow nicely. Then jam as the patterns change, using the RGB BUTTONS and the SPREAD and AMOUNT knobs TETRACHORDS | USER GUIDE PAGE | 79...
Page 80: Overview
Buttons 5 to 8 assign CV OUT 1 to 4, in Gate Mode, to the selected track. The assigned outputs send a gate signal, scaled according to the MIDI velocity value of the current note. TETRACHORDS | USER GUIDE PAGE | 80...
Page 81: Polyphonic Example
When TRACK 1 is playing and the ARP CHORD button is set to CHORD, the 4 CV OUTS can transmit up to 4 different notes/ voltages. The way it works depends on how many notes are active. (cont.) TETRACHORDS | USER GUIDE PAGE | 81...
Page 82 When 3 notes are active, CV OUTS 1, 2 & 3 transmit the active notes/ voltages. CV OUT 4 duplicates note 1. RGB Button 1 note RGB Button 5 note RGB Button 7 note RGB Button 1 note (cont.) TETRACHORDS | USER GUIDE PAGE | 82...
Page 83 RGB Button 5 note E.g. when all notes are active, notes 5, 6, 7 & 8 are omitted. RGB Button 1 note RGB Button 2 note RGB Button 3 note RGB Button 4 note TETRACHORDS | USER GUIDE PAGE | 83...
Page 84: Gate Out Example
For details of how to manipulate note velocity, refer to MIDI Velocity section of this guide. For details of how the gate output responds to the CV input, refer to the Trig Input Response appendix. TETRACHORDS | USER GUIDE PAGE | 84...
Page 85: Slew
CV notes. When turned fully clockwise, the transition between CV notes is as slow as possible, approximately 5.5 seconds. Note that the transition time is independent of the distance between sequenced notes. TETRACHORDS | USER GUIDE PAGE | 85...
Page 86: Current Track Lfo
Sets the LFO depth for all CV OUTS assigned to the current track. Note: the controls described above can be used to synchronize the LFOS of all CV outputs assigned to a track. TETRACHORDS | USER GUIDE PAGE | 86...
Page 87: Edit All Cv Lfos
KNOBS 5 to 8 Set the LFO amount for CV OUTS 1 to 4 respectively. The controls described above can be used to independently set the LFOS of all CV outputs assigned to a track. TETRACHORDS | USER GUIDE PAGE | 87...
Page 88: Midi Input
Tracks 1-4 Left/Right buttons RGB Buttons 5-8 Select which track you Move between MIDI channels Assign MIDI IN channel in are currently editing 1-16 in 4 pages shown on the Pills Simple Triggers mode TETRACHORDS | USER GUIDE PAGE | 88...
Page 89 Connections The Tetrachords accepts MIDI input via 3.5mm stereo jack and USB C. The Tetrachords is configured as a class compliant USB C device. This means there is no need to install drivers but it will only pair with a USB host.
Page 90: Simple Trigger
MIDI channels 1-4 respectively. Simple Trigger mode mirros the functionality of the Trig input of each track but instead of using analogue trig and gate signals it uses the incoming MIDI notes. (cont.) TETRACHORDS | USER GUIDE PAGE | 90...
Page 91: Quantisation
MIDI ch. 1 (in) Track 1 QUANTISE CV OUT 1 To turn off quantisation, so the Tetrachords functions as a MIDI through and MIDI to CV/I2C box: Press and hold the SHIFT button then press and hold OCTAVE/MIDI IN. SHIFT can be released at this stage.
Page 92: Channel Configuration
The bottom row of RGB buttons correspond to MIDI IN channels 1-4 in Simple Trigger mode. Pressing an RGB button toggles the corresponding MIDI channel as an input for the current track. TETRACHORDS | USER GUIDE PAGE | 92...
Page 93 4 groups of 4 channels. The brighter pill indicates the active page: 1st page The LEFT and RIGHT buttons navigate between pages. Press the RIGHT button to move to the next page (cont.) TETRACHORDS | USER GUIDE PAGE | 93...
Page 94 The RGB buttons now allow configuration of MIDI channels 5-8. 2nd page MIDI channels 9-12. 3rd page MIDI channels 13-16. 4th page (cont.) TETRACHORDS | USER GUIDE PAGE | 94...
Page 95: Midi To Cv
Assign CV OUTS 1 to 4 to TRACK 1 (page 81.) Connect a MIDI keyboard to the Tetrachords and set it to output on MIDI channel 1. Press and release a single note on the MIDI keyboard. All 4 CV OUTS will transmit a pitch corresponding to that single note.
Page 96 TRACKS 1, 2, 3 & 4 respectively. In-between notes trigger multiple TRACKS as illustrated above. Additionally, notes C# and D# cause TRACK 1, and any linked TRACKS, to progress to the previous or next PATTERN. (cont.) TETRACHORDS | USER GUIDE PAGE | 96...
Page 97: Channel Configuration
The selected channel is illuminated with the current track colour. A single channel 1 - 16 can be selected. To select channels 9-16, turn the encoder clockwise, past the 8th setting. (cont.) TETRACHORDS | USER GUIDE PAGE | 97...
Page 98 The LED ring now displays channels 9-16. Here, MIDI channel 9 is selected. TETRACHORDS | USER GUIDE PAGE | 98...
Page 99: Overview
1 to 4 respectively. MIDI is output via the 3.5mm stereo jack and USB C. The Tetrachords is configured as a class compliant USB C device. This means there is no need to install drivers however, it will only pair with a USB host.
Page 100: Midi Output
Enabled channels are illuminated with the current track colour. Notes generated by the current track will output to every enabled MIDI channel. Up to 16 output channels can be set per track. (cont.) TETRACHORDS | USER GUIDE PAGE | 100...
Page 101 8 channels. The brighter pill indicates the active page: 1st page 2nd page The LEFT and RIGHT buttons navigate between pages. TETRACHORDS | USER GUIDE PAGE | 101...
Page 102: Overview
MIDI Velocity Overview When the SHIFT button is pressed and held, the five knobs below manipulate MIDI velocity values of sequenced notes. TETRACHORDS | USER GUIDE PAGE | 102...
Page 103: Midi Velocity
Press SHIFT and turn the INVERSION / CHORD VEL knob. This sets the MIDI velocity for notes played when the ARP CHORD button is set to CHORD. CHORD VEL is set to 75 by default. (cont.) TETRACHORDS | USER GUIDE PAGE | 103...
Page 104: Random Velocity
This adds a random component to the MIDI velocity of notes in the current pattern. The VEL RANDOM setting effects all notes, regardless of the ARP CHORD button setting. VEL RANDOM is set to 15% by default. (cont.) TETRACHORDS | USER GUIDE PAGE | 104...
Page 105: Midi Velocity Spread
The VEL AMOUNT knob has no effect at the 12 o’clock position. When turned clockwise, the VEL AMOUNT knob increases the velocity of selected notes. When turned counter-clockwise, the VEL AMOUNT knob decreases the velocity of selected notes. TETRACHORDS | USER GUIDE PAGE | 105...
Page 106 (Buttons 1 - 4) (Buttons 5 - 8) In this setting, notes at the beginning of the SETTING 2 pattern will always be louder than those at the end. (cont.) TETRACHORDS | USER GUIDE PAGE | 106...
Page 107 In this setting, the amount knob affects SETTING 3 only the odd notes of the pattern. In this setting, the amount knob affects SETTING 4 only the even notes of the pattern. (cont.) TETRACHORDS | USER GUIDE PAGE | 107...
Page 108 In this setting, the amount knob affects SETTING 5 only the middle notes of the pattern. In this section, the amount knob affects SETTING 6 only the outer notes of the pattern. TETRACHORDS | USER GUIDE PAGE | 108...
Page 109: Midi Cc
MIDI CC Pressing and holding SHIFT, then pressing the PROG/MIDI CC button puts the Tetrachords in MIDI CC MODE. Turning any of the 8 knobs generates MIDI CC messages. Each knob has a dedicated MIDI CC number and transmits values from 0-127.
Page 110: Example Patch
1, MIDI CC 22. Initialise the Tetrachords . Press SHIFT then press and hold PROG/MIDI CC to put the Tetrachords in MIDI CC MODE. SHIFT can be released at this point. Turn the PATH KNOB. As the PATH KNOB is turned, the Tetrachords streams MIDI CC messsages on MIDI CC 22.
Page 111 Turn the PATH KNOB fully counter- clockwise. The MIDI CC setting is stored in the current Tetrachords PATTERN, number 1. Release PROG/MIDI CC Hold PATTERN then press the RIGHT button to copy the current PATTERN to the next PATTERN slot.
Page 112 The 4th white LED pill goes dark indicating that MIDI CC on the 4th knob i.e. PATH, is inactive. Release PROG/MIDI CC MIDI CC messages will no longer be generated as patterns change. TETRACHORDS | USER GUIDE PAGE | 112...
Page 113: Encoder Overview
ROTARY ENCODER in MIDI CC MODE. Initialise the Tetrachords. Press SHIFT then press and hold PROG/MIDI CC to put the Tetrachords in MIDI CC MODE. SHIFT can be released at this point. Press the ENCODER BUTTON. When the BUTTON is pressed, the Tetrachords transmits a value of 1 on MIDI CC 32.
Page 114 Turn the ENCODER As the ENCODER is turned, the Tetrachords streams MIDI CC messsages corresponding to the selected NOTE LEDS E.g. here the ENCODER will send a value sending a value of 8 over MIDI CC 32. Release PROG/MIDI CC...
Page 115 CV Modulation Overview Almost any of the Tetrachords’ settings may be precisely controlled via CV. Below is a quick example. The pages that follow explain the process in full and provide further examples. Plug a CV source into MOD 1.
Page 116: Cv Modulation
CV Modulation The 6 MOD inputs can be used to control any (almost) of the Tetrachords’ settings via CV. Each input can be assigned to modulate multiple settings. Set up works as follows: Press the MOD button. NOTE When the MOD button is pressed, LEDs will flash to indicate any parameter that is being modulated by the currently selected mod (see next step for mod selection).
Page 117: Select Mod Input
LEDs flash to indicate any parameter assigned to the newly selected MOD. The LED RING displays the value of any CV signal received by the selected mod. Positive CV Negative CV Max CV +5V (cont.) TETRACHORDS | USER GUIDE PAGE | 117...
Page 118: Select Mod Response
In trigger mode, an incoming trigger causes the targeted control to cycle through its possible settings. By default, MOD 1 - MOD 5 are set to bi-polar response and MOD 6 is set to trigger. (cont.) TETRACHORDS | USER GUIDE PAGE | 118...
Page 119: Select Mod Target
Use MOD 5 & MOD 6 for Triggers All mods can respond to trigger inputs, however, MOD 5 & MOD 6 have been designed to be more responsive and so are the best choice for time-sensitive trigger modulations. (cont.) TETRACHORDS | USER GUIDE PAGE | 119...
Page 120: Fine Tune Mod Response
As do all 6 LEDs surrounding the TETRACHORD 1 KNOB. PHRYGIAN LYDIAN HARMONIC In this way the display indicates that the incoming CV may set the TETRACHORD 1 control to any of its 6 possible values. (cont.) TETRACHORDS | USER GUIDE PAGE | 120...
Page 121: Disabling Mods
At this point, de-selecting all of the RGB buttons disables modulation of the selected control. The RESET button works as a short cut for this. See the UNMOD section for a full rundown on how to disable MOD’s . (cont.) TETRACHORDS | USER GUIDE PAGE | 121...
Page 122: Invert Mod Response
With the MOD button held, pressing LINK or JAM/READ/WRITE, inverts the LED display and mod response.. PHRYGIAN PHRYGIAN LYDIAN HARMONIC LYDIAN HARMONIC BIPOLAR UNIPOLAR LYDIAN HARMONIC PHRYGIAN LYDIAN TRIGGER TETRACHORDS | USER GUIDE PAGE | 122...
Page 123: Remove Cable
Remove the cable from the physical MOD input. Removing the cable temporarily disables any modulations associated with that MOD input. The MOD settings aren’t deleted when the cable is removed. Modulation resumes if the cable is plugged back in. TETRACHORDS | USER GUIDE PAGE | 123...
Page 124: (I) Musical Mode
Press RGB BUTTON 3 to select MOD 3 as the physical input Use RGB BUTTON 8 to select unipolar (0 to 5v) input. UNIPOLAR (0v to 5v) The AMOUNT 2 LED pulses right to indicate the unipolar setting. (cont.) TETRACHORDS | USER GUIDE PAGE | 124...
Page 125 MODE value to modes 1, 2, 4 or 6. Note that the buttons act as a toggle. For example, pressing RGB BUTTON 5 again will make mode 5 accessible to CV modulation. Release the MOD button. TETRACHORDS | USER GUIDE PAGE | 125...
Page 126: (Ii) Midi Out
MOD button. Press RGB BUTTON 5 to select MOD 5 as the physical input Use RGB BUTTON 8 to select trigger input. TRIGGER The AMOUNT 2 LED blinks to indicate the trigger setting. (cont.) TETRACHORDS | USER GUIDE PAGE | 126...
Page 127 LEFT and active. RIGHT buttons. Press RGB button 2 to enable CV control of MIDI channel 2. Incoming triggers now cycle the active MIDI OUT channel between MIDI channel 1 and 2. (cont.) TETRACHORDS | USER GUIDE PAGE | 127...
Page 128 Press RGB button 1 to enable CV control of MIDI channel 9. Release the MOD button. Incoming triggers now cycle the active MIDI OUT channel. MIDI CHANNEL 1 MIDI CHANNEL 2 MIDI CHANNEL 9 MIDI CHANNEL 1 TRIGGER TETRACHORDS | USER GUIDE PAGE | 128...
Page 129: (Iii) Rev
Press RGB BUTTON 2 to select MOD 2 as the physical input Use RGB BUTTON 8 to select unipolar (0 to 5v) input. UNIPOLAR (0v to 5v) The AMOUNT 2 LED pulses right to indicate the unipolar setting. (cont.) TETRACHORDS | USER GUIDE PAGE | 129...
Page 130 Press the REV 1 BUTTON At this point, RGB button 1 illuminates, indicating the incoming CV can set REV 1 on or off. Release the MOD button. TETRACHORDS | USER GUIDE PAGE | 130...
Page 131: (Iv) Vel Level
Use RGB BUTTON 8 to select bipolar (-5v to 5v) input. BIPOLAR (-5v to 5v) The AMOUNT 2 LED oscillates to indicate the bipolar setting. Press and hold SHIFT then turn the AMOUNT/VEL AMOUNT knob (cont.) TETRACHORDS | USER GUIDE PAGE | 131...
Page 132 50% and highest 12.5% of values from CV control. Incoming CV can now set the MIDI velocity level to between 50% and 87.5% of the MIDI velocity range. Release the MOD button. TETRACHORDS | USER GUIDE PAGE | 132...
Page 133: (V) Next Pattern(Mod 6 Default)
Type of input: Next Pattern Targeted Settings: Next PATTERN modulation is enabled by default. When a CV trigger is received on MOD 6, the next PATTERN, if there is one, will play. (cont.) TETRACHORDS | USER GUIDE PAGE | 133...
Page 134 Shift Button Many of the Tetrachords controls have primary and secondary functions. Secondary functions are accessed using the SHIFT button. For example, pressing and holding the SHIFT button, then turning the PATH knob sets the amount of slew applied to the CV output.
Page 135: Overview
Songs & Progressions Overview A SONG is the highest-level Tetrachords structure. A SONG consists of 8 PROGRESSIONS, labelled PROG on the faceplate. Each PROGRESSION can contain up to 8 PATTERNS TETRACHORDS | USER GUIDE PAGE | 135...
Page 136: Saving
NOTE - to see which SONG slot is currently selected, press and hold SONG/SAVE. The white LED pills will indicate the current SONG slot. INITIALISING A SONG Hold SONG then press the RESET to clear/initialise the current SONG and all PROGRESSIONS within it. TETRACHORDS | USER GUIDE PAGE | 136...
Page 137: Progressions
Hold PROGRESSION then press the RIGHT button to copy the current PROGRESSION to the next PROGRESSION slot. Hold PROGRESSION then press the LEFT button to copy the current PROGRESSION to the previous PROGRESSION slot. (cont.) TETRACHORDS | USER GUIDE PAGE | 137...
Page 138 INITIALISING PROGRESSIONS Hold PROGRESSION then press the RESET to initialise the current PROGRESSION and all PATTERNS within it. TETRACHORDS | USER GUIDE PAGE | 138...
Page 139: Overview
In a Eurorack system, i2c connections are typically made on the under side of modules. Currently, the Tetrachords is i2c compatible with the Expert Sleepers Disting EX, and the Mannequins Just Friends. More integrations are planned. Contact us with any requests or suggestions.
Page 140: Physical Connection
SCL and SDA lines connectered to a power source via what are known as ‘pull-up resistors’. On the Tetrachords, pull-up resistors can be enabled or disabled via a switch located beside the 3-pin i2c connector. It is possible to daisy chain i2c connections. Some modules, such as the Just Friends have double connectors to facilitate this.
Page 141: Tetrachords Configuration
Disting Ex Press the ENCODER BUTTON to activate/de-activate the connection for the selected track. When i2c is activated, the LED corresponding to the connected device will assume the colour of the selected TRACK. TETRACHORDS | USER GUIDE PAGE | 141...
Page 142 With the power to both modules off, physically connect the Tetrachords and Disting Ex i2c headers. The Tetrachords and Disting Ex both have i2c pull-up resistor enable switches. Ensure that one, and only one of these is enabled. With the Disting Ex powered on, enter the top level settings menu and then select MIDI/I2C page 1.
Page 143 This is because a handshake occurs between the Disting Ex and the Tetrachords when an i2c connection is activated. During this handshake, the Tetrachords learns what algorithm the Disting Ex is running and adjusts it’s settings accordingly. (cont.)
Page 144: #14 Quad Envelope
#14 QUAD ENVELOPE Starter settings for a Quad Envelope with Envelopes 1 - 4 paired to Tetrachords CV outs 1 - 4. Each time a Tetrachords CV OUT is updated, the corresponding envelope is triggered. With this setup, Shape 1 is the shape for all 4 envelopes.
Page 145: #19 Macro Oscillator
Starter settings for a single* voice routed to Disting Ex outputs 1 & 2. * Technically there are 4 voices but the Tetrachords’s chord feature isn’t currently compatible with the Resonator algorithm. Resonator → Parameter 26: Audio input → 0 0 None.
Page 146: Macro Oscillator
Poly FM → Parameter 16 : Output 2 → 4 Outputs 1/2 Poly FM → Parameter 23 : Output 3 → 4 Outputs 1/2 Poly FM → Parameter 30 : Output 4 → 4 Outputs 1/2 TETRACHORDS | USER GUIDE PAGE | 146...
Page 147: Just Friends
- Just Friends When Connected to the Tetrachords via i2c Just Friends operates in its Synthesis Mode, operating as a six voice polysynth with voices dynamically assigned. CONNECTION With the power to both modules off, physically connect the Tetrachords and Just Friends i2c headers.
Page 148: Utility Buttons
Utility Buttons The SHIFT, RESET and LATCH buttons have utility functions on the Tetrachords. This section details the utility functionality. TETRACHORDS | USER GUIDE PAGE | 149...
Page 149 Shift Many of the Tetrachords controls have primary and secondary functions. Secondary functions are accessed using the SHIFT button. For example, pressing and holding the SHIFT button, then turning the PATH knob sets the amount of slew applied to the CV output.
Page 150 CASCADING INVERSIONS PHRYGIAN LYDIAN HARMONIC ACTIVATE/DEACTIVATE PATTERN MODE Press and hold SHIFT, then press and hold PATTERN (SHIFT can then be released). Then use the RGB BUTTONS to deactivate and reactivate patterns. (cont.) TETRACHORDS | USER GUIDE PAGE | 151...
Page 151 SHIFT TO INITIALISE SONGS/PROGRESSIONS/PATTERNS The SHIFT button can also be used to clear SONGS, PROGRESSIONS or PATTERNS, functioning as an ergonomic alternative to the RESET button. INITIALISE SONG INITIALISE PROGRESSION INITIALISE PATTERN TETRACHORDS | USER GUIDE PAGE | 152...
Page 152: Secondary Functions
For reference, an exhaustive list is given below but in practice, if you would like to initialise or clear something, try pressing RESET INITIALISE SONG INITIALISE PROGRESSION INITIALISE PATTERN INITIALISE (CLEAR) THE STEP SEQUENCER STEP SEQ (cont.) TETRACHORDS | USER GUIDE PAGE | 153...
Page 153 INITIALISE MIDI IN SETTINGS INITIALISE MIDI OUT SETTINGS INITIALISE MIDI CC SETTINGS INITIALISE TUNING SETTINGS INITIALISE CV OUTS INITIALISE RANDOM SETTINGS TETRACHORDS | USER GUIDE PAGE | 154...
Page 154: Delay And Synchronize Changes
Tapping the LATCH button once decouples this playing/editing link, making it possible to navigate to PATTERNS that aren’t playing and edit them. Tapping LATCH once more to returns the module to regular operation. TETRACHORDS | USER GUIDE PAGE | 155...
Page 155 LATCH button is released. This feature makes it possible to synchronize the timing of multiple simultaneous changes. EXAMPLE Initialise the Tetrachords then press and hold the LATCH button. Turn the TETRACHORD 1 knob to MIN. PHRYGIAN LYDIAN HARMONIC Press RGB buttons 1 &...
Page 156 It is now possible to navigate to PATTERNS or PROGRESSIONS that aren’t playing and edit them. Tapping LATCH once more to returns the module to regular operation. The UI will again display the currently playing pattern. TETRACHORDS | USER GUIDE PAGE | 157...
Page 157 Firmware Update The Tetrachords firmware can be updated using the SD card. The latest firmware file can be found at https://cycleinstruments.com/resources/ Below is an overview of the button combinations to enter the firmware update menu. The pages that follow explain the update procedure in full.
Page 158: Firmware Update
Download and unzip the firmware file e.g. tetrachords_1_1_1_2.bin_. zip. Place the unzipped .bin file into the root directory of the micro SD card. Insert the card into the Tetrachords. Whilst holding down the SHIFT and TRACK 1 buttons, power up the Tetrachords. PHRYGIAN...
Page 159 Don’t turn off the power, plug anything in or otherwise interact with the module whilst it is updating. The progress of the update is represented on the LED ring. Tetrachords will reboot once the update process is complete. TETRACHORDS | USER GUIDE PAGE | 160...
Page 160: Config Text File
Config Text File A configurable text file is included on the Tetrachords SD card. It is possible to edit this text file to configure some of the default settings of the Tetrachords. To streamline this process, an online configuration editor is available at https://cycleinstruments.com/tetrachords-config/...
Page 161: Faq / Troubleshooting
FAQ / Troubleshooting TETRACHORDS | USER GUIDE PAGE | 162...
Page 162 Appendix TETRACHORDS | USER GUIDE PAGE | 163...
Page 163 Appendix 1 - Track Input Response When the Tetrachords receives a MIDI NOTE ON message or detects the rising edge of a CV GATE, up to three things happen. 1 or more MIDI NOTE ON messages are transmitted via any active MIDI OUTPUTS.
Page 164 This symbol represents a Inputs are blue MIDI note on message This symbol represents a Outputs are black MIDI note off message. TRIG IN RESPONSE TRIG IN CV OUT PITCH CV OUT VELOCITY MIDI Time (cont.) TETRACHORDS | USER GUIDE PAGE | 165...
Page 165 CV OUT PITCH CV OUT VELOCITY MIDI Time Note that the CV OUT pitch does not respond to a MIDI note off message or to the falling edge of a CV TRIG IN signal. TETRACHORDS | USER GUIDE PAGE | 166...
Page 166 Acknowledgements The Tetrachords module was created on the stolen lands of the Turrbal and Yaggera people in Meinjin, Australia. We would like to thank everyone who have generously shared with us the knowledge to bring this module to life. Specifically, all the people behind the...
Page 167 CYC LE I NST RUME N TS ADDRESS 3/26 Venning St Everton Park QLD 4053 Australia CONTACT info@cycleinstruments.com cycleinstruments.com...

CYCLE INSTRUMENTS Tetrachords Manual

Reading this Guide

Before You Start

Getting Started

Tuning Mode

Scales 1

Patterns

Tracks

Octaves

Inversions

Spread

Arp / Chord

Path

Reverse

Chromatic

Keyboard Mode

Step Sequencer

Reset

105 CV out

MIDI Input

MIDI Output

CV Modulation

Songs & Progressions

I2C

Utility Buttons

Firmware Update

Config Text File

FAQ / Troubleshooting

Quick Links

Need help?

Questions and answers

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Summary of Contents for CYCLE INSTRUMENTS Tetrachords

Table of Contents