Buchla 242t Programmable Pulser

Tiptop Audio 16HP
SEQUENCER CLOCK TRIGGER GATE

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Licensed Eurorack reissue of the Buchla 200-series 242 pulser. 4×12 LED matrix replaces the original pin matrix — three independent pulse patterns (A/B/C) clocked by an internal period from 2ms to 10s+ per stage, plus alternating, all-pulse and ramp outputs.

Patch Ideas · 12

★ Three-part polymetric drum pattern
program A=kick pattern (length 4), B=hats (length 7), C=snare (length 12) · same internal clock · each MATRIX output to its drum voice · classic Buchla-style polymetric groove that never repeats the same way for 84 bars
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: 242t, Kick, Hats, Snare. Signals: 3 gate.242tKickHatsSnaren(A)=4, n(B)=7, n(C)=12: A: 1,3 · B: 1,4,6 · C: 5,9,11PERIOD: ~125ms (120 BPM sixteenths)MATRIX AgateMATRIX BgateMATRIX CgateTriggateTriggateTriggategate
★ Direct LPG strike via ramp
ramp OUT to 292t (or any vactrol LPG) CV · matrix A triggers the 259t/258t voice · each stage fires a self-enveloping note with no extra envelope module needed · PERIOD knob shapes the decay
▸ Show diagram
Patch diagramPatch diagram with 3 modules and 3 connections. Modules: 242t, VCO, LPG. Signals: 1 audio, 1 cv, 1 trigger.242tVCOLPGA: 1,3,5,7PERIOD: ~400msRamp OUTcvMATRIX AtrigTrigtrigOutaudioInaudioCVcv11. self-striking rampaudiocvtrigger
Ping-pong stereo envelopes
ALL OUT drives a steady pulse · wait, use ALTER 1 → L envelope, ALTER 2 → R envelope · two mono voices get alternating triggers · result = stereo ping-pong rhythmic pattern without any logic or switch module
▸ Show diagram
Patch diagramPatch diagram with 3 modules and 2 connections. Modules: 242t, Env L, Env R. Signals: 2 trigger.242tEnv LEnv RPERIOD: 250msALTER 1trigALTER 2trigTrigtrigTrigtrigtrigger
Externally-clocked pattern with kept ramp
master clock to CLK IN · matrix runs in sync to rack tempo · but ALL OUT and ramp keep running on the internal PERIOD — use the ramp for free-running modulation that does not sync to clock while the matrix stays tight
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: 242t, Master Clock, Filter, VCO. Signals: 1 cv, 1 trigger, 1 clock.242tMaster ClockFilterVCOInternal PERIOD: 1.3s (modulation rate)CLK INclkMATRIX AtrigRamp OUTcvOutclkCutoffcvTrigtrig121. synced rhythm2. free-running modcvtriggerclock
Audio-rate matrix drone
PERIOD at full CCW (~2ms) · matrix A and B programmed with different patterns · outputs become audio-rate square-wave-like tones whose harmonic content depends on the on/off pattern · through a filter for subtractive-style lead
▸ Show diagram
Patch diagramPatch diagram with 3 modules and 3 connections. Modules: 242t, Filter, VCA. Signals: 3 audio.242tFilterVCAPERIOD: fully CCW (~2ms)A: 1,2,4,6,8 · B: 1,3,5,9MATRIX AaudioMATRIX BaudioInaudioOutaudioInaudio11. sum via inaudio
CV-swept tempo
slow LFO to PERIOD CV input · attenuverter sets sweep depth · matrix keeps pattern, but period swells and contracts over time · great for accelerando/decelerando gestures with hands-free
▸ Show diagram
Patch diagramPatch diagram with 3 modules and 2 connections. Modules: 242t, LFO, Drum. Signals: 1 cv, 1 trigger.242tLFODrumA: 1,4,7,10PERIOD attenuverter: 2 o'clockPERIOD CVcvMATRIX AtrigOutcvTrigtrig11. tempo breathescvtrigger
Reset to cut pattern short
program A=12 stages but send a reset pulse at stage 8 via external source · matrix wraps early · combine with CLK IN for effective variable pattern length driven by external gate logic
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: 242t, Master Clock, Reset Trig, Drum. Signals: 2 trigger, 1 clock.242tMaster ClockReset TrigDrumA: 1-12 all onVia CLK IN: CLK INclkRST INtrigMATRIX AtrigOutclkOuttrigTrigtrig11. cut pattern earlytriggerclock
Start/stop performance transport
use start and stop buttons (or CV) as live transport · hold stop during breakdowns, punch start to re-enter · single-pulse button fills with one-off hits during pauses · patterns resume from where they stopped
▸ Show diagram
Patch diagramPatch diagram with 3 modules and 3 connections. Modules: 242t, Footswitch, Drum. Signals: 2 gate, 1 trigger.242tFootswitchDrumA: 1,3,5,7,9,11start INgatestop INgateMATRIX AtrigStartgateStopgateTrigtriggatetrigger
★ Generative melody via ALL OUT + quantizer
ALL OUT steady clock · matrix A triggers a random/S&H voice · B triggers a second voice · C triggers an accent · three-voice generative line with polyrhythm between them
▸ Show diagram
Patch diagramPatch diagram with 7 modules and 7 connections. Signals: 1 cv, 2 pitch, 1 gate, 2 trigger, 1 clock.242tS&HVCONoiseQuantizerDrumAccent Drumn(A)=5, n(B)=7, n(C)=3: ALL OUTclkMATRIX AgateMATRIX BtrigMATRIX CtrigIncvTrigclkOut1v/octV/Oct1v/octGategateOutcvIn1v/octOut1v/octTrigtrigTrigtrigcvpitchgatetriggerclock
Ratchet fills via audio-rate + gate
main slow pattern on MATRIX A · use a VCA in its signal path whose CV comes from a gate source · when gate opens, let a second 242t at audio-rate pass through — creates ratcheting fills on demand · single module + VCA trick
▸ Show diagram
Patch diagramPatch diagram with 5 modules and 4 connections. Modules: 242t, Fast 242t, VCA, Mixer, Drum. Signals: 2 audio, 1 gate, 1 trigger.242tFast 242tVCAMixerDrumA: 1,3,5,7 · PERIOD: 300msMATRIX AtrigALL OUTaudioInaudioCVgateOutaudioIn 2audioTrigtrig1231. main pulse2. audio-rate3. ratchet when gatedaudiogatetrigger
Matrix ALL + A/B as clock divider
ALL OUT = master clock · program A to fire on stages 1,5,9 (÷4) · B on 1,7 (÷6) · C on 1 (÷12) · single module emits master clock plus three integer divisions for tempo-locked modulations
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 4 connections. Modules: 242t, Envelope, LFO Trigger, Filter. Signals: 1 cv, 2 trigger, 1 clock.242tEnvelopeLFO TriggerFilterA: 1,5,9 · B: 1,7 · C: 1ALL OUTclkMATRIX AtrigMATRIX BcvMATRIX CtrigTrigclkResettrigCutoffcv12341. master2. ÷43. ÷6 slow accent4. ÷12 downbeatcvtriggerclock
Self-patched tempo nudge
ALTER 1 into PERIOD CV with attenuverter mostly CCW · every other stage gives a tiny tempo kick · feels like swing or humanized drift baked into the pulser itself
▸ Show diagram
Patch diagramPatch diagram with 2 modules and 2 connections. Modules: 242t, Drum. Signals: 1 cv, 1 trigger.242tDrumA: 1,3,5,7,9,11PERIOD attenuverter: 10 o'clock (small)PERIOD CVcvALTER 1cvMATRIX AtrigTrigtrig11. subtle swingcvtrigger

Behaviors

Three-row independent matrix program cells in rows A, B, C

Rows A, B, C each output their own pulse pattern through their own jack. The 'n' row at the top selects how many of the 12 stages are active per row — patterns of different lengths can run simultaneously against each other, producing polymeter (e.g. A=5, B=7, C=12).

Internal vs external clock patch CLK IN

External clock on CLK IN takes over stage advance for MATRIX A/B/C and the ALTER outputs. However, ALL OUT and the ramp output remain driven by the internal clock period — so external clocking does not silence the internal pulse/ramp.

Ramp for LPG strike patch gray Ramp OUT to 292t-style LPG

The gray ramp output is specifically designed to open a Buchla 292t (or any vactrol LPG) directly without needing an envelope generator. The ramp's falling slope acts as the decay envelope; period controls the LPG's decay time.

Ping-pong via ALTER pair patch both ALTER outputs to paired destinations

The two ALTER jacks split every-other pulse — pulse 1 to jack 1, pulse 2 to jack 2, pulse 3 to jack 1 again, etc. Use for stereo ping-pong triggering of two drum voices, or left/right envelopes, without any logic module.

Audio-rate operation turn PERIOD offset fully CCW (.002s)

Period range extends to ~2ms, which is audio-rate (~500Hz fundamental). The ALL OUT and matrix outputs become clock-like square waves suitable as audio sources for PWM-style patches or unusual drones.

OFF position stops internal clock PERIOD offset full CW past '10'

Panel label .002-10-OFF: past the '10-seconds' end the knob hits OFF, halting the internal clock. Lets you freeze playback with one gesture without touching the stop button or a stop pulse.

Long-press matrix clear hold on/off button

Long press of the on/off button clears all programmed pulse cells. Shorter press only toggles the currently-selected cell. Use for fresh starts during live programming without navigating to each cell.

Pulse-length jumper trade-off move rear jumper to Short

Default 'Long' = 1ms fixed width, compatible with envelope-generator triggers. 'Short' uses the pulser's native (much briefer) width or the CLK IN pulse width directly — useful when clocking fast digital destinations that might miss a 1ms pulse-train edge.

Controls

Internal clock PERIOD offset Right knob · sets base stage period from ~2ms (audio rate) to ~10 seconds or longer · labeled .002 to 10/OFF
CW past '10' reaches OFF, stopping the internal clock
Internal clock PERIOD attenuverter Left knob · bipolar CV attenuator on period modulation · adds or subtracts from offset knob
Enables CV-controlled tempo/period sweeps
Matrix edit Vertical-row encoder Lower-left knob · scrolls cursor through rows n / A / B / C to select which row is edited
Combined with horizontal encoder to address a matrix cell
Matrix edit Horizontal-row encoder Lower-right knob · scrolls cursor through stages 1-12
Combined with vertical encoder to address a matrix cell
Matrix edit on/off button Toggles the currently-selected matrix cell on/off · long press clears the whole matrix
'n' row selects stage count; A/B/C rows set pulse pattern per output
Transport start button Manually starts the internal clock and matrix playback
Also triggered by start input on INPUTS jack
Transport single pulse button Emits one manual pulse without starting the clock
Useful for step-advance testing or filling in patterns live
Transport stop button Manually stops the internal clock
Also triggered by stop input on INPUTS jack
Global output Pulse-length jumper (rear) Short = pulser's internal brief width or CLK IN width · Long = fixed 1ms · factory default Long for Eurorack compatibility
Back of module; requires removing from rack

I/O

IN · 5

  • start IN gate/trigger GATE
    Pulse input · rising edge starts the internal clock
  • stop IN gate/trigger GATE
    Pulse input · rising edge stops the internal clock
  • PERIOD CV ±5V typical CV
    Modulation CV scaled by the PERIOD attenuverter · sweeps stage period across the full range
  • CLK IN gate/trigger GATE
    External clock input · replaces internal clock for stage advance · each rising edge advances one stage
  • RST IN gate/trigger GATE
    External reset · returns playback to the end stage / wraps the pattern

OUT · 6

  • ALL OUT gate/trigger GATE
    Continuous pulse train at the internal (or CLK IN) rate regardless of matrix content · direct tap on the pulser
  • MATRIX A gate/trigger GATE
    Pulses programmed in row A of the matrix · active on stages 1 to 'n'
  • MATRIX B gate/trigger GATE
    Pulses programmed in row B of the matrix
  • MATRIX C gate/trigger GATE
    Pulses programmed in row C of the matrix
  • ALTER (×2) gate/trigger GATE
    Two jacks emitting alternating pulses from the pulser · pulse N goes to one, N+1 to the other · ping-pong rhythm pairs
  • Ramp OUT (gray) 0-10V ramp
    Continuous falling ramp synced to the pulser · spans one stage period · ideal for driving a 292t LPG strike directly