Every module of Rasgo Modular explained on three levels — what it is, where it sits among its neighbours, and a chain to try. It is the same text the LEARN box shows inside the instrument when you hover a module's body; here it is all together, to read before or after playing.
Quick Subtractive oscillator — the starting voice. Saw/square/triangle/sine with PW and organic drift; tracks 1 V/oct.
How it works This is the 'classic' source; WAVETABLE sweeps tables, ADDITIVE sums partials, OPERATOR does FM.
Try this OSC → FILTER → VCA with an ENVELOPE on the gate: the minimum chain of a synthesiser.
Quick Wavetable oscillator — a POS knob sweeps a bank of waveforms, from smooth to spectral, anti-aliased.
Try this Slow LFO → POS: the timbre 'breathes' between the waves.
Quick Additive oscillator — sums up to 64 partials; TILT/ODD-EVEN/STRETCH sculpt the spectrum directly.
How it works Builds timbre by adding sines, the opposite of FILTER (which takes away from a rich sound).
Quick 4-operator FM, 8 algorithms, DX7-style feedback — brass, bells and basses the subtractive path will not make.
Try this Whole-number RATIO = harmonic; fractional = inharmonic (bell).
Quick Pulsar synthesis (Curtis Roads) — a train of pulsarets (grain + silence) with TWO independent frequencies: FREQ is the pitch, FORMANT the timbre. Between granular and formant synthesis.
How it works OPERATOR/ADDITIVE pin the spectrum to the pitch; here FORMANT slides the spectral envelope WITHOUT detuning. MASK/JITTER thin out and misalign the train (burlesque patterns, seeded).
Try this LFO → FQM: 'wah' with no filter. MASK ~0.7 + JITTER ~0.4 = an irregular rhythmic cloud over the same note.
Quick Spectral resynthesis — it LISTENS to a sound, finds the strongest partials and re-oscillates as a bank of sines that follows it. The analysis → synthesis bridge (Panharmonium / phase vocoder).
How it works ADDITIVE builds the spectrum from nothing; MEMORY grains in time; here the material is the short-term spectrum of the input. FREEZE = an endless pad from any sound. With no IN, seeded noise feeds the analysis → a drone that evolves on its own.
Try this DRUM → IN, low VOICE, STRETCH = a bell-like shadow of the rhythm; FRZ ← gate = frozen spectrum alternating with the live one.
Quick Phase-locked loop — locks phase to an input and generates divisions/multiplications of it; left free, it self-oscillates.
How it works It is oscillator AND clock extractor — it follows what it hears, within a capture window.
Quick Chord voice — 3–4 oscillators tuned by an interval/inversion; one note in, a chord out.
Quick Noise and continuous chance — white/pink/brown/blue/violet/bit + S&H + a wandering voltage, 8 outputs at once.
How it works DECISION decides events; NOISE gives the floor and the random CVs. POIS swaps the internal clock for free Poisson.
Quick Physical-modelling voice — matter excited (blown/rubbed/struck) and ringing; stiffness/tension/wear as knobs.
Quick Extended Karplus-Strong string — pluck/bow/hammer into a delay line with damping and material.
Quick Percussion voice — body with pitch sweep + attack click; an 808 ↔ 909 ↔ acoustic map, and ROLL.
Quick The way in from the world — live audio (ALSA) + MIDI in a single adapter; monophonic last-note voice with pitch/gate/vel/cc outputs.
How it works It is the INPUT counterpart of NOTE-OUT. With nothing connected, deterministic silence.
Quick Resonant multimode filter — LP/BP/HP, with resonance reaching self-oscillation (it becomes a sine).
How it works Takes energy away from a rich sound (subtractive); WASP distorts on the way, LPG closes with a vactrol.
Try this ENVELOPE → cutoff_mod: the classic 'wah'. RES near the top + low cutoff = a tunable sine voice.
Quick Bank of 5 parallel bandpasses — the resonances of vowels; VOWEL morphs A→E→I→O→U. VOCODER>0 + the MOD jack = a 5-band vocoder (the bands follow the modulator's envelope instead of the vowel table).
How it works Fant's source-filter model; in vocoder mode, Dudley's channel (1938).
Try this On noise or pulses: synthetic speech. On a chord: a choir. Voice into MOD + saw into IN + VOCODER=1: the synth 'speaks'. For intelligible wideband speech, use the dedicated VOCODER.
Quick N-band vocoder (4–20) — the MODULATOR's energy per band controls the gain of that same band in the CARRIER: the carrier 'speaks' the modulator. Homer Dudley, 1938.
How it works FORMANT has a 5-band (vowel) vocoder mode; this is the dedicated, wideband one (intelligible speech). SIBIL passes the fricatives; FREEZE = an endless spoken pad; SHIFT = formant shift.
Try this Voice into MOD + saw or pad into CAR + BANDS=16 = the classic. With no CAR, the internal saw is tuned by PIT.
Quick Bank of up to 24 modes TUNED to a series, excited by an EXTERNAL signal (you strike it with whatever you like). Rings/Elements in resonator mode.
How it works MATTER is a closed voice (its own exciter); here you bring the excitation. The 3 outputs LOW/MID/HIGH CROSS OVER as you sweep TILT — the relation between them is the process (Three Sisters).
Try this DRUM → IN (a marimba played by the kick); TRIGSEQ → STRK; RESONATOR.low and .high into different destinations.
Quick Filter-distortion — the dirty, shouted character of the EDP Wasp; the non-linearity sits IN the filter path.
Quick Low-pass gate — filter + VCA in one control, with vactrol asymmetry (fast attack, slow tail). The Buchla 'bongo'.
Try this Ping it with a short trigger: the LPG gives body and decay in one gesture.
Quick Voltage-controlled amplifier — volume/level as CV; linear or exponential response.
Quick Bank of 4 VCAs plus a summed mixer (MIX). `VCA` (#20) is dual; this is the bank for a large patch — Mutable Veils / Intellijel Quad VCA.
How it works The linear/exp CURVE is SHARED. Each channel: LVL + attenuverted CV (summed at the port). MIXG sets the gain of the sum.
Try this The 3 low/mid/high outputs of RESONATOR/FILTER into 3 channels + an envelope on each CV = a spectrum that moves; MIX brings it together.
Quick Waveshaper — folds/saturates/rectifies the waveform to create harmonics; from subtle warmth to destruction.
Quick Frequency shifter — moves the WHOLE spectrum by so many Hz (not by a ratio). The partials stop being harmonic → metallic, bell-like. SSB: `up` (+Δf) and `down` (−Δf) outputs.
How it works SHAPE's ring-mod gives BOTH symmetric sidebands; SHIFTER gives one per output. FEEDBACK = Risset's 'barber pole' (endless glissando). Bode/Moog frequency shifter.
Try this SHIFT ~8 Hz = a phase that never closes; large SHIFT + FEEDBACK = the Shepard spiral; `up`/`down` into different destinations.
Quick Lo-fi destroyer / decimator — DIGITAL rubbish: rate reduction (aliasing), bit reduction, wrapping overflow, glitch (dropout/stuck/stutter) and clock jitter.
How it works This is where the verb DAMAGE lives. SHAPE/WASP distort in an ANALOGUE way (fold, tanh); here it is quantisation, integer overflow, a bad connection. All seeded → reproducible damage.
Try this ENVELOPE → BITS (resolution falls away in the tail); LFO → RATE; no IN + MIX=1 = a lo-fi noise source.
Quick Parametric EQ — bell and shelf bands to sculpt the spectrum surgically, without filter resonance.
Quick Portamento/slew — slides between values instead of jumping; separate time for rise and fall, constant or proportional mode.
Quick Continuous CV utilities — attenuverter, offset, rectification as a lerp, slew. The pocket knife of the control signal.
Quick Envelope generator — AD/ADSR/AR and loops; the shape of amplitude (or of any CV) over time, fired by a gate.
Try this ENVELOPE → VCA + ENVELOPE → cutoff: the contour of the sound.
Quick Maths-style function generator — a deformable ramp/envelope/LFO with derived outputs; it sums, integrates, fires.
How it works It is envelope AND LFO AND slew, all in the curve. DRIFT is a slow walk; CHAOS is genuinely chaotic.
Quick Generator of N configurable segments (2–8) whose FUNCTION EMERGES from how they chain: ramps → envelope/LFO, steps → a CV sequence. Mutable Stages / Rossum Control Forge.
How it works FUNCTION is ONE ramp; STAGES is the COMPOUND shape, sculpted by CONTOUR/TILT/HOLD (a generator, not an editor). HOLD=0 slides (env), HOLD=1 jumps (seq); LOOP runs ↔ fires.
Try this STAGES → FILTER.cutoff; CLOCK → GATE (loop off) = an envelope; STAGES.step → ENVELOPE.gate chains them.
Quick Field of organic drift — several correlated CVs wandering slowly (on the scale of minutes), with momentum and an anchor to recorded landmarks.
How it works It gives LIFE without direction — nothing stays still. Deterministic (seeded).
Quick Double-well chaotic field — a deterministic ODE that settles in one well, oscillates between two, or 'hunts' unpredictably.
How it works Genuinely chaotic, not pseudo-random (DECISION/TURING) nor a filtered walk (DRIFT).
Quick Dual sample & hold — holds a value on a pulse; 2 channels with CORRELATION (twins ↔ mirror ↔ independent) and slew.
Try this CLOCK → SH · out1 → pitch · out2 → cutoff: a melody and a timbre that 'go together'.
Quick Euclidean master clock — a pulse with divisions, euclidean fill, swing and drift; the beat of the whole patch.
Try this CLOCK → everything with a gate or trigger. FILL spreads the pulses across the bar (Toussaint's patterns).
Quick Clock logic — divide/multiply, AND/OR/XOR of gates, delay; it recombines TIME.
How it works The partner of ABACUS (which does CV arithmetic). Here it is gates and triggers only.
Quick Random shift register (Turing Machine) — a loop of bits that LOCK holds and MUTATE reshuffles; melody/rhythm that repeats with variation.
Quick 8-step sequencer — pitch sliders + direction (forward/back/ping-pong/random/brownian), with a gate per step.
Try this The sliders are the score — the Motion Engine barely touches them. Use MUTATE/EVOLVE to reshuffle on purpose.
Quick TRIGGER sequencer — 4 lanes of euclidean density with chaos/ratchet/fill/swing; the generative percussion.
Quick Scale quantiser — snaps a CV to the degrees of a scale and key; slew and hysteresis so it will not flutter at the edge.
Try this SH/TURING/DRIFT → QUANTIZER → pitch: a random walk becomes a melody in the scale.
Quick Harmoniser — from one note it generates intervals and chords coherent with a key and with a voice leading.
Quick CV arithmetic — add/subtract/multiply/modulo and bitwise AND/OR/XOR between two signals, plus a binary counter whose bits become rhythm (Numeric Repetitor).
How it works The partner of LOGIC (which recombines time). On its own, the counter already plays a sequence and a rhythm.
Quick Source of STRUCTURED chance, Marbles-style — distribution (bias/spread/shape), déjà-vu (repeats the pattern), steps and slew; it makes CV and gates with 'intent'.
Quick Boxcar averager — a window samples one point of the period, and the average of N captures reveals the signal inside the noise; SCAN reconstructs the wave; GEIG = Poisson gates.
How it works It is the SCOPE in reverse: it measures in order to BUILD a wave. mode 0 = windowed S&H, 1 = reconstructs, 2 = reads its own buffer back as an oscillator.
Try this Noise plus a weak tone synchronised to TRIG, mode 1, high SCAN: the tone 'draws itself' over seconds.
Quick Switch/router — N inputs → 1 output (or 1 → N), by clock step, CV or at random; it sequences SOURCES instead of notes.
Quick 4×4 routing matrix — any input to any output with a gain per cell; a programmable CV/audio mixer.
Quick Buffered multiple — copies a signal to several destinations with no level drop; dual mode and optional slew.
Quick XY vector morph — slides between 4 sources on a plane; the gesture (the path across the plane) can be recorded and replayed.
Quick Reverberation — a multitap Schroeder/Dattorro network, from short ambience to a long tail; pre-delay and damping.
How it works SPACE is the 'classic' reverb; HALL is an 8-line FDN (denser, stereo); MEMORY is granular.
Quick 8-line FDN reverb with a Householder matrix — a dense stereo tail, with FREEZE (endless hold) and pre-delay.
Quick Delay line with HOLD (freezes and repeats), REVERSE (plays backwards without a click), AGE (tape/BBD character) and HEADS (multi-head echo, Space Echo style).
How it works The old 'TAPE' became this HEADS. FBK near 1 + a long TIME + several heads = Frippertronics.
Quick MODULATION effects — chorus, flanger, ensemble and phaser in one module (TYPE). SHORT delays modulated by an LFO (plus the phaser, a cascade of all-passes), with BBD character in AGE.
How it works RASGO had none of these. Distinct from LOOPER (a delay line, audible echoes) and from reverb — here you hear the MOVEMENT, not the echo.
Try this voice → SWIRL → MASTER thickens it; LFO → RATE lets the sweep breathe off the bar; FBK near ±1 + AGE = it self-oscillates.
Quick Granular — a buffer chopped into grains (grain/cloud/spray), with position, size, density and FREEZE; textures and time-stretch.
Quick Slice player (MPC/Akai) — TRIG fires a passage recorded live (REC gate) or from a file; varispeed, slices + POS, repitch, wear.
How it works SAMPLER jumps the read position (a slice); TURNTABLE reads continuously with inertia; MEMORY is granular.
Quick Turntable with a platter that has mass — the SAMPLER's buffer read by an angular velocity with INERTIA: the motor pulls slowly (TORQ), the hand pushes (SCR), the brake lets it coast (BRK).
How it works NO BPM quantisation — beatmatching is a gesture, as on vinyl.
Try this LFO → SCR: the record scratches in time. ENVELOPE → BRK: a tape-stop on the turnaround.
Quick 4-channel mixer — level (slider), pan and mute per channel plus a master out. Where the musician does the balance.
How it works Exempt from the Motion Engine — the pans and levels are yours.
Quick Stereo output stage — width, body guard and a true-peak limiter; the ceiling of the patch.
How it works Exempt from the Motion Engine. The header's STANDBY button is this module's mute.
Quick Oscilloscope and meter that GIVES BACK as CV — pitch (YIN), envelope, spectral centroid, ONSET (a pulse on the attack); the patch hears itself.
How it works SCOPE measures in order to reduce (→ a scalar); BOXCAR measures in order to reconstruct (→ a wave).
Try this SCOPE.onset ← drums → fires an ENVELOPE in time with the audio; SCOPE.pitch → OSC.pitch tunes to whatever comes in.
Quick MIDI out — converts gate + 1 V/oct into note on/off, with channel, velocity and a score log.
How it works The OUTPUT counterpart of SIGNAL-IN.
Lúcio Araújo — authorship and development. Bugs, licence, credit: