Quadrax

Intellijel 14HP

fw 1.2.1

4-channel CV-controllable function generator. Each channel independently operates as AD/AHR envelope, cycling LFO, pulse burst generator, or morphing bipolar LFO. Channels chainable via flexible link options.

Patch Ideas · 6

★ Four-stage ADSR chain

CH1 AD · CH2–4 AD · CH2 EOR-linked to CH1, CH3 EOF-linked to CH2, CH4 EOF-linked to CH3 · one trigger cascades through all four.

Walkthrough

Patch a gate source into CH1 TRIG.
Short-press CH1 MODE until it is unlit (AD mode).
Short-press CH2 MODE until unlit, then short-press CH2 LINK until it turns green (EOR link to CH1).
Repeat for CH3 and CH4 but cycle LINK until yellow (EOF link).
Set CH1 RISE fast, FALL medium; CH2 RISE/FALL medium; CH3 slower; CH4 longest.
Patch OUT 1 → VCA, OUT 2 → second VCA, OUT 3 → filter cutoff, OUT 4 → final VCA or reverb send.
Fire a trigger and watch the envelopes cascade one after another.

Signal out Four staggered envelopes on OUT 1–4 · unipolar 0–10V (or 0–5V in System Mode).

Listen for A single gate produces a multi-stage swell: fast attack, layered decays, and a long evolving tail as each channel takes over from the last.

▸ Show diagram

★ Polyrhythmic envelope farm

CH1 slow CYCLE LFO seeds the rhythm · CH2 EOR-linked fires at each cycle peak · CH3 EOF-linked fires at each cycle bottom.

Walkthrough

Short-press CH1 MODE until green (CYCLE); set RISE and FALL fairly slow for a slow wave.
Short-press CH2 MODE until unlit (AD); short-press CH2 LINK until green (EOR).
Short-press CH3 MODE until unlit (AD); short-press CH3 LINK until yellow (EOF).
Set CH2 and CH3 RISE/FALL short so they make percussive envelopes.
Patch OUT 1 → filter cutoff, OUT 2 → one VCA, OUT 3 → another VCA.
Listen: CH1 slowly sweeps the filter while CH2 and CH3 punch at different phases of that sweep.

Signal out OUT 1 slow unipolar LFO · OUT 2/3 short AD envelopes firing on opposite halves of the cycle.

Listen for A slow breathing filter sweep with two percussive hits per cycle, phased so they feel like a rolling polyrhythm rather than a steady beat.

▸ Show diagram

Internal PWM

CH1 LFO with SHAPE near square · CH2 slow CYCLE routed via CV A → CH1 FALL (morph), modulating the pulse width dynamically.

Walkthrough

Short-press CH1 MODE until magenta (LFO); turn RISE clockwise for audio-rate or medium for sub-LFO.
Adjust SHAPE until the waveform is a square (see LFO shape chart).
Short-press CH2 MODE until green (CYCLE); set CH2 slow.
Patch OUT 2 → CV A input on Quadrax.
Long-press CH1 LINK/CV to enter CV assign mode; press CV A, then press the FALL destination until green (positive attenuversion).
Long-press CH1 LINK/CV to exit CV assign mode.
Patch OUT 1 → mixer or VCA input.
Hear the square pulse width breathe in time with CH2.

Signal out OUT 1 — bipolar ±5V square/pulse with morphing width.

Listen for A classic PWM pad or bass tone whose pulse width drifts slowly on its own, no external LFO required.

▸ Show diagram

LFV random CV

One channel in ALTERNATE LFO (LFV) · RISE sets vacillation rate · FALL sets variance · SHAPE smooths · optional clock into TRIG for tempo-sync.

Walkthrough

Short-press CH1 MODE until magenta (LFO).
Long-press CH1 MODE until it pulses (ALTERNATE / LFV).
Optional: patch a clock into TRIG 1 so vacillations lock to tempo.
Set RISE for rate, FALL for how wildly values jump, SHAPE CW to slew corners smooth.
Patch OUT 1 → a destination like VCO FM, filter cutoff, or wavefolder.

Signal out OUT 1 — bipolar ±5V non-repeating chaotic CV.

Listen for Organic, wandering modulation that never repeats. Low variance is a drunken walk; high variance is wide random jumps.

▸ Show diagram

★ Sidechain duck envelope

CH1 AD on kick trigger for kick VCA · CH2 AD longer on same trigger · CH2 OUT through inverter → bass VCA so bass ducks each kick hit.

Walkthrough

Set CH1 and CH2 to AD mode (MODE unlit).
Multiple the kick trigger into TRIG 1 and TRIG 2.
Set CH1 RISE fast, FALL short — the kick VCA envelope.
Set CH2 RISE fast, FALL longer — the duck envelope.
Patch OUT 1 → kick VCA CV, OUT 2 → inverter → bass VCA CV.
Raise the bass VCA's bias/offset so bass is normally open; each kick envelope now subtracts from it.

Signal out OUT 1 — kick envelope (0–10V); OUT 2 — duck envelope (0–10V, inverted downstream).

Listen for Bass dips every time the kick hits, no compressor needed. Adjust CH2 FALL for pump length.

▸ Show diagram

Envelope ↔ LFO mutual modulation

CH1 CYCLE (self-cycling) and CH2 LFO cross-modulate each other through the CV matrix: OUT 1 → CV A → CH2 rate, OUT 2 → CV B → CH1 rise.

Walkthrough

Set CH1 MODE to green (CYCLE) for a self-running envelope.
Set CH2 MODE to magenta (LFO), free-running (TRIG 2 empty).
Patch OUT 1 → CV A, OUT 2 → CV B.
Long-press CH2 LINK/CV; press CV A; press RISE destination to assign CV A → CH2 Rise.
Long-press CH1 LINK/CV; press CV B; press RISE destination to assign CV B → CH1 Rise.
Long-press whichever LINK/CV is flashing magenta to exit CV assign mode.
Patch OUT 1 → a VCA CV input for something audible.

Signal out OUT 1 — unipolar cycling envelope used as audible modulator; OUT 2 — bipolar LFO feeding back internally.

Listen for A slowly evolving, never-quite-repeating modulator. Each channel's motion bends the other, giving life to static patches.

▸ Show diagram

Behaviors

AD Mode trigger → TRIG input

Classic attack/decay envelope. Completes full cycle on trigger; ignores gate length. RISE = attack, FALL = decay, SHAPE = curve. ALTERNATE mode inverts curve assignment per stage.

AHR Mode gate → TRIG input

Attack/Hold/Release envelope. Attacks on gate rise, sustains at peak while gate is high, releases on gate fall. RISE = attack, FALL = release, SHAPE = curve.

CYCLE Mode free-running or trigger reset

Cycling unipolar LFO. RISE + FALL set frequency and shape of cycle. Trigger resets phase. GATE input times ignored.

BURST Mode trigger → TRIG input

Pulse burst generator. RISE sets pulse rate (0.05Hz–3.33kHz), FALL sets burst envelope length (0.3ms–20s), SHAPE defines individual pulse shape and overall amplitude curve. Alternate: tilting sawtooth shape.

LFO Mode (Standard) free-running or clock → TRIG

Bipolar ±5V LFO. RISE = rate (free) or clock multiplier/divider (clocked, ±64×). SHAPE selects waveshape, FALL morphs the waveform. Multiple clocked LFOs can phase-sync.

LFO Mode (Alternate / LFV) free-running

Chaotic Low Frequency Vacillator. RISE = vacillation rate, FALL = max variance per cycle, SHAPE = slew amount. Creates organic, non-repeating modulation.

Channel Linking link button per channel

Three link modes: Trigger (simultaneous fire), EOR (fire at attack peak), EOF (fire at decay end). Enables multi-stage envelope chains. Combining link with own TRIG OR's the two sources.

Controls

CH 1–4	Rise	Attack time (AD/AHR/CYCLE) or pulse rate (BURST) or LFO rate (LFO). CCW = fastest. AD/AHR: 0.05ms–20s · BURST: 0.05Hz–3.33kHz · LFO: 0.05Hz–3.33kHz
CH 1–4	Fall	Decay/release time (AD/AHR/CYCLE), burst length (BURST), or LFO morph (LFO). CCW = fastest. AD/AHR: 0.05ms–20s · BURST length: 0.3ms–20s · LFO: morph/variance
CH 1–4	Shape	Response curve shape for Rise and Fall. Noon = linear. STANDARD/ALTERNATE alters behavior. STANDARD: CCW = logarithmic · CW = exponential · ALTERNATE: inverts per stage
CH 1–4	LED	Amplitude indicator. Green = positive voltage, red = negative voltage. Brightness indicates output level
CH 1–4	LINK/CV Button	Short press cycles link mode (No Link, Trigger, EOR, EOF). Long press enters CV Assignment mode. If own TRIG is also patched, link source + TRIG are OR'd (Multiple Triggers). CH2 triggered by CH1 · CH3 by CH2 · CH4 by CH3 · CH1 by CH4
CH 1–4	MODE/DESTINATION Button	Short press cycles mode: AD (unlit) → AHR (red) → CYCLE (green) → BURST (yellow) → LFO (magenta). Long press toggles STANDARD/ALTERNATE operation. In CV assign mode: sets destination (Rise/Fall/Shape/Level) and attenuversion amount

I/O

IN · 2

TRIG 1–4 >2V gate GATE

Trigger/gate input per channel. Fires envelope, resets CYCLE/LFO, clocks BURST. LFO uses as clock for beat-sync.
CV A–D ±5V (clips at ±5V; accepts ±10V) CV

Four freely-assignable CV inputs. Each can modulate Rise, Fall, Shape, or Level on any channel via internal CV matrix with per-assignment attenuversion.

OUT · 1

OUT 1–4 0–10V (unipolar) or ±5V (LFO)

Main output per channel. AD/AHR/CYCLE/BURST: unipolar 0–5V or 0–10V (user selectable). LFO: bipolar ±5V.

Expanders

Qx 4HP

4HP expander for Quadrax (also works with Gx). Adds one End-of-Rise and one End-of-Fall gate output per Quadrax channel — 8 gate outs total. Behavior follows each channel's current Quadrax mode (AD/AHR/CYCLE/BURST/LFO).

Behaviors

AD mode gates Quadrax channel set to AD

EOR goes high at the peak of the attack and stays high for the entire decay, then drops to 0V. EOF is the inverse: high during rise, goes low at the attack peak, stays low through the decay, then goes high at the end of decay.

AHR mode gates Quadrax channel set to AHR

EOR goes high at the end of attack and stays high through hold and release. EOF goes low at the start of the release phase and high at the end of release.

CYCLE mode gates Quadrax channel set to CYCLE

EOR is high during the decay half of each cycle, low during rise. EOF is the inverse (180° opposite). Effectively a square wave at the LFO rate on each output — useful as a clock or complementary gate pair.

BURST mode gates Quadrax channel set to BURST

EOR pulses high at the start of every individual pulse inside the burst (per-pulse clock). EOF goes high once at the very end of the whole burst (burst-complete flag).

LFO mode gates (STANDARD) Quadrax channel set to LFO (standard)

EOR goes high at the LFO midpoint and drops when the cycle resets — a square at LFO rate. EOF is the inverse (180° opposite): high for the first half of the cycle, low for the second.

LFO mode gates (ALTERNATE) Quadrax channel set to LFO (alternate / LFV)

EOR is high whenever the LFO voltage is moving negative; EOF is high whenever it's moving positive. Complementary direction flags from the chaotic vacillator.

Works with Gx Gx used in place of Qx

Identical circuit with generic labels 1–8 instead of EOR/EOF pairs. Connects to Quadrax via I2C the same way.

Patch Ideas · 4

Cascaded 4-stage envelope

Use EOF gates to chain each Quadrax AD envelope into the next.

Walkthrough

Set Quadrax CH 1–4 all to AD mode (MODE button unlit).
Dial Rise and Fall on each channel to taste — CH 1 short, CH 2 medium, CH 3 long, CH 4 long release.
Patch your trigger source → Quadrax CH 1 TRIG.
Patch Qx EOF 1 → Quadrax CH 2 TRIG.
Patch Qx EOF 2 → Quadrax CH 3 TRIG.
Patch Qx EOF 3 → Quadrax CH 4 TRIG.
Patch Quadrax OUT 4 → VCA CV to hear the final stage (or mix OUT 1–4 for a running envelope).

Signal out Quadrax OUT 4 — the final envelope stage, 0–5V or 0–10V depending on System Mode.

Listen for One incoming trigger unrolls a four-part envelope: stage 1 fires, stage 2 waits for 1 to finish and then rises, and so on. Great for long evolving pads or multi-stage percussion hits.

▸ Show diagram

Per-pulse drum fills from BURST

BURST mode + EOR gives one trigger per pulse inside the burst — EOF flags the end.

Walkthrough

Set Quadrax CH 1 to BURST mode (MODE button yellow).
Set CH 1 Rise for pulse rate (noon ≈ musical 16th-note range).
Set CH 1 Fall for the overall burst length (how many pulses).
Patch your clock → Quadrax CH 1 TRIG to fire a burst per beat.
Patch Qx EOR 1 → drum-voice TRIG — one hit per pulse inside the burst.
Patch Qx EOF 1 → a second voice's TRIG (e.g. crash) — fires once when the burst ends.

Signal out Qx EOR 1 — 0–5V gate per pulse. Qx EOF 1 — 0–5V gate at burst end.

Listen for A rolling drum fill on EOR that ends with an accent on EOF. Change CH 1 Rise to speed up or slow down the roll; change Fall to make the fill longer or shorter.

▸ Show diagram

Alternating clocks from one LFO

A single CYCLE channel gives you two complementary square clocks on EOR and EOF — 180° inverse, half-period offset.

Walkthrough

Set Quadrax CH 1 to CYCLE mode (MODE button green).
Set CH 1 Rise and Fall to match — this sets the LFO period.
Patch Qx EOR 1 → Sequencer A clock input.
Patch Qx EOF 1 → Sequencer B clock input.
Patch Quadrax OUT 1 → Filter Cutoff for the triangle LFO itself.

Signal out EOR 1 and EOF 1 — two 0–5V square clocks, 180° inverse (one high while the other is low). OUT 1 — the triangle LFO itself.

Listen for Two sequencers step in alternation off the same LFO — Sequencer A ticks on the rise half, Sequencer B on the fall half. The filter breathes with the underlying triangle.

▸ Show diagram

AHR release-detect trigger

EOF goes high the moment a note's release ends — perfect for chaining a second event.

Walkthrough

Set Quadrax CH 1 to AHR mode (MODE button red).
Set Rise for attack, Fall for release.
Patch your gate source → Quadrax CH 1 TRIG.
Patch Quadrax OUT 1 → VCA CV (main voice).
Patch Qx EOF 1 → a second envelope / sample trigger (fires after the note fully dies).

Signal out Qx EOF 1 — 0–5V gate at the moment release completes.

Listen for Every time the main note finishes fading out, a second event fires — echo-tail, reverb swell, ghost note, or a sampled 'breath' after the word. EOR instead fires at the peak, if you want the second event on the way in.

▸ Show diagram

I/O

OUT · 8

EOR 1 0–5V gate GATE

End-of-Rise gate for Quadrax CH 1. Fires when the rise stage completes. Exact behavior depends on CH 1's mode (see behaviors).
EOF 1 0–5V gate GATE

End-of-Fall gate for Quadrax CH 1. Fires when the fall/release stage completes. Exact behavior depends on CH 1's mode.
EOR 2 0–5V gate GATE

End-of-Rise gate for Quadrax CH 2.
EOF 2 0–5V gate GATE

End-of-Fall gate for Quadrax CH 2.
EOR 3 0–5V gate GATE

End-of-Rise gate for Quadrax CH 3.
EOF 3 0–5V gate GATE

End-of-Fall gate for Quadrax CH 3.
EOR 4 0–5V gate GATE

End-of-Rise gate for Quadrax CH 4.
EOF 4 0–5V gate GATE

End-of-Fall gate for Quadrax CH 4.

Patch Ideas · 6

Behaviors

Controls

I/O

▸ IN · 2

◂ OUT · 1

Expanders

Behaviors

Patch Ideas · 4

I/O

◂ OUT · 8

IN · 2

OUT · 1

OUT · 8