Discrete Track — manual

A threshold map. One moving input scans 32 stages; whichever threshold it crosses fires that stage's note and gate. Drive it from an internal ramp for melody, or from external CV for quantizing.

Introduction

The Discrete track does not step through a sequence of notes. It watches one moving input — an internal ramp or an external CV — and fires one of up to 32 stages whenever that input crosses the stage's threshold in the stage's direction. The stage that fires emits a note (CV) and a gate. Sweep the input and the map plays back as a melody; drive it from outside and the same map becomes a quantizer / CV shaper.

It is a stateless ramp engine. Nothing is remembered between ticks: each tick recomputes the ramp phase from the clock position, compares the current input against the previous input, and lets any crossed threshold claim the active stage. Pause, reset, or change pattern and the whole picture rebuilds from the clock.

Everything here is grounded in the firmware as built — defaults, ranges, enum members, key bindings, and step-grid maps come from the model, engine, and UI code.

Prerequisites

• Familiarity with the xformer track/sequence/edit page model (Page+S2 / Page+S1 / Page+S0).
• Understanding of CV/gate concepts in modular synthesis, in particular 1V/oct pitch and ±5V CV.
• For External mode, a routing channel set up to feed the track's input.

Part 1 · Overview

The track owns 32 stages. Each stage holds three things:

• a threshold (−100..+100), the position in the voltage window it watches,
• a direction (Rise / Fall / Off / Both), the edge it watches for,
• a note index (−63..+63), the scale degree it emits when it fires.

A single moving input scans the window. When it crosses a stage's threshold in that stage's direction, that stage becomes the active stage: its note converts to output CV and a gate fires. The active stage holds until another stage's threshold is crossed (an Off active stage releases to silence).

The input comes from one of three clock sources:

• Internal Saw a −5V→+5V sawtooth ramp, period set by the divisor.
• Internal Tri a −5V→+5V triangle (up then down), same period.
• External a routed CV input (the DMap Input route).

Part 2 · Input & Stages

Clock source and the ramp

The internal ramp always spans the full ±5V, regardless of the Above/Below range — the range only moves where the thresholds sit, not where the ramp goes. Internal Saw rises linearly −5V→+5V then snaps back; Internal Tri rises −5V→+5V over the first half of the period and falls +5V→−5V over the second.

Period in ticks is divisor ÷ (clock multiplier as a fraction): a higher clock multiplier shortens the period (faster sweeps), a higher divisor lengthens it. External ignores the internal ramp and reads the DMap Input route value (clamped −5V..+5V) as the live input each tick.

Loop vs Once

Loop (default) cycles the ramp forever. Once sweeps a single period, then holds its final value (+5V, phase 1.0) and stops until a reset or a Loop↔Once toggle restarts it.

Stage direction

Stages are scanned in index order and the first crossing wins. A stage stays active until some other stage is crossed. The init/default direction is Off.

Threshold modes: Position vs Length

The Above (rangeHigh) and Below (rangeLow) params define the voltage window the thresholds live in. The mode decides how each stage's −100..+100 maps into that window:

Changing the range or the mode marks the threshold cache dirty and recomputes on the next tick.

Note index → CV

A stage's note index (−63..+63) is a scale degree. Output volts come from the sequence's selected scale: noteToVolts(noteIndex + octave·notesPerOctave + transpose). On a chromatic scale the root note adds root × (1/12) volts. The Offset param adds a flat CV bias (centivolts ×0.01 = volts) on top of the resolved note.

The CV Update mode (track-scope) decides when pitch params are read:

• Gate (default) — octave / transpose / root are sampled at the gate trigger. Changing them mid-note does not retune the held note until the next gate. Muted in Gate mode, CV output drops to 0V.
• Always — pitch params read live every update; CV updates continuously regardless of stage changes.

Part 3 · Gate, Slew & Pluck

Gate length

When a new stage becomes active, a gate fires for a length derived from the step. Gate Len 0% = "T" is a fixed short pulse (a few ticks), independent of step length; 1..100% is that percentage of the step's tick length.

Slew

Slew (0 = Off, 1..100%) smooths CV between stages by limiting the pitch rate — up to 48 semitones/sec at Slew=1 (fast), scaling down to a slow glide near Slew=100. With Slew off the CV jumps instantly. Slew enabled also flags the outgoing MIDI note as a slide.

Pluck

Pluck (−100..+100, 0 = Off) adds a pitch transient at note onset. The note starts bent away from its target and decays linearly back to pitch:

• magnitude up to ~200 cents (2 semitones), onset glide 10..450ms, both scaled by a square curve of |Pluck|;
• sign sets direction: Pluck > 0 bends up into the note, Pluck < 0 bends down;
• higher |Pluck| adds more random jitter (10%..50%) to depth and time, so repeated notes vary.

Part 4 · Playback Timing

Sync = Reset realigns the ramp to a bar boundary every Reset Measure bars (a reset re-zeros the ramp to −5V/phase 0 and clears stage/CV/gate/pluck state). The legacy External sync member is inert — re-anchor from outside via a Reset route instead.

Play Mode (track-scope) is Aligned (ramp phase locks to the bar grid) or Free (ramp runs from its own free clock position).

Part 5 · The Sequence Page

Page+S0 opens the Discrete edit page (header DMAP). It draws a threshold bar across the top, a live input cursor, and a three-row info block for the eight stages of the current section. Four sections of eight stages each; LEFT / RIGHT step through them.

The footer (F1-F5), normal mode

The F2 range macros snap Above/Below to a preset window:

The step keypad (S1-S16)

Two rows of 8, acting on the eight stages of the current section:

• Bottom row (S1-S8) = stage SELECT. Plain press selects exclusively; holding one and pressing another multi-selects. Holding a bottom key drives the engine monitor (auditions that stage's note while stopped). Shift + bottom = toggle in/out of the selection without changing edit mode.
• Top row (S9-S16) = direction EDIT. Plain press selects that stage and cycles its direction (Off→Rise→Fall→Both). Shift + top = select every stage sharing the pressed stage's direction.

The encoder

Pressing the encoder toggles the edit mode between Threshold and Note. It then edits the selected stage(s):

• Threshold — ±1 fine, ±10 with Shift (clamped −99..99).
• Note — ±1; Shift jumps an octave on chromatic scales only.
• All 32 selected switches to a rotate of all values: thresholds rotate (Shift fine / no-Shift ×8 coarse), note indices rotate one step.

Stage edit LEDs

• Top row (direction): Rise green, Fall red, Both yellow, Off unlit.
• Bottom row (select/active): selected yellow, active-but-unselected green, else unlit.

The OLED threshold bar marks each non-Off stage as an upward tick (tallest = active, mid = selected) and draws the live input as a bright cursor. The info block shows direction char / threshold / note name per stage, the active stage brightest.

Part 6 · Generators, Voicings & Macros

The context menu

The context-menu key opens: INIT, COPY, PASTE, GEN.

• INIT enters a footer target submenu: ALL / THR / NOTE / (blank) / X. ALL clears the whole sequence (re-seeds the fret-pattern thresholds, all stages Off, notes 0); THR re-seeds thresholds only; NOTE zeroes notes.
• COPY / PASTE copy and paste the whole sequence (paste enabled only when the clipboard holds a Discrete sequence).
• GEN enters the generator.

GEN (generator)

GEN runs in two footer steps. First a kind: RAND / LIN / LOG / EXP / X. Then a target:

• RAND target row: ALL / THR / NOTE / TOG / X (TOG randomizes directions).
• LIN/LOG/EXP target row: ALL / THR / NOTE5 / NOTE2 / X — NOTE5 spreads notes wide (−63..+64), NOTE2 narrow (0..+32). Threshold shaping is linear / √ / ^1.3 across −99..99.

Page+Step quick edits

Range High / Low / Divisor open the standard quick-edit overlay. Voicing quick-edits apply a chord shape across the active stages (selection-limited if more than one selected); the selected stage's note is the root, C0 resets from the track/project root, ROOT is a safe no-op.

• Piano banks: ROOT, C0, MAJ13, MAJ6/9, MIN13, MIN6/9, MINMAJ9, DOM13, M9B5, DIM7, AUG9, AUGMAJ9, SUS2(9), SUS4(11).
• Guitar banks: ROOT, C0, MAJ, MIN, 7, MAJ7, MIN7, 6, MIN6, 9, 13, SUS2, SUS4, ADD9, AUG, M7B5, DIM7.

Page+Step macros

Four step combos open threshold/note macro menus (yellow LEDs):

• Page+S5 Distribution: I-8, I-5(2), I-7(3), I-9(4), I-FRET. Even-distribute thresholds across stage groups; I-FRET round-robin interleaves across the four sections.
• Page+S6 Cluster: M-CLUSTER, M-AR4, M-SWELL, M-ISWELL, M-STRUM. Operate on active stages (selection-limited if more than one selected).
• Page+S7 Distribute Active: E-ACT, E-RISE, E-FALL, E-BOTH, NORM. Even-spread thresholds by direction filter; NORM expands the current spread to fill −100..+100.
• Page+S15 Transform: FLIP, T-REV, T-INV, N-MIRR, N-REV. FLIP cycles all directions; T-* transform thresholds; N-* transform note indices.

Part 7 · The Scanner

The DMap Scan route lets an external CV reshape the map live. Route a CV source to DMap Scan (value 0..34):

• 0 = bottom dead zone, 1..32 = stages 0..31, 33/34 = top dead zone.
• Each time the scanned value enters a new stage's segment, that stage's direction cycles (Off→Rise→Fall→Both).

Sweep a fader or slow LFO across the scan input to "draw" directions across the map in real time. The dead zones at the extremes toggle nothing.

Part 8 · Setup & Routing

Track-scope list (Page+S2)

Track-wide params, hosted by the generic Track page:

• Play Mode (Aligned / Free)
• CV Update (Gate / Always)

Sequence-scope list (Page+S1)

Per-pattern params, in order: Clock, Sync, Divisor, Clock Mult, Gate Len, Loop, Reset Measure, Threshold (mode), Above, Below, Scale, Root, Scale Rotate, Slew, Pluck, Octave, Transpose, Offset.

What is routable

Routing targets exposed for a Discrete track:

• DMap Input — the External-mode input CV (−5..+5V).
• DMap Scan — the scanner (0..34, cycles stage directions).
• DMap Above (rangeHigh) and DMap Below (rangeLow) (−5..+5V).
• Shared sequence/track params: Divisor, Clock Mult, Scale, Root Note, Slew (Slide Time), Octave, Transpose, Offset.

Initialization (the fret pattern)

INIT (ALL) re-seeds every stage with an interleaved fret-pattern threshold distribution — round-robin across the four sections, ~6.5 units apart overall — with all directions Off and all notes 0. Enabling a stage (changing its direction) lights up a pre-spaced threshold without re-placing it.