Membrane

A physical-modeling percussion voice. Instead of playing back a sample, Membrane synthesizes a struck drumhead: a hit fires a short excitation into a bank of 16 resonant modes — tuned to the natural ratios of a real drum — and each mode rings and fades on its own. The result is a living, never-quite- repeating drum that responds to how, where, and how hard you strike it. One module covers frame drums, toms, congas, and tabla.

Patch it

  • strike — the hit. Send a trigger or gate (a clock, a sequencer gate, a

Patch Start, a keyboard gate). Each rising edge strikes the head once.

  • pitch — 1V/oct pitch CV, added on top of the Tune knob — play melodies on

the drum from a keyboard or sequencer.

  • pos — strike-position CV (adds to the Pos knob): move the contact point per

hit for round-vs-bright variation.

  • accent — velocity CV. Unpatched = full level; +5 V hits harder (louder,

punchier, and a deeper pitch glide), −5 V silences. Patch an envelope or random source for human dynamics.

  • bend — tension/pitch-bend CV. Bends the whole drum's pitch up or down by

changing the head tension (±5 V ≈ ±a fifth). Patch an envelope here for the tabla bayan's heel-of-hand "gish" glide, or an LFO for a wobble.

  • out — mono audio.

Controls

VOICE

  • Model — the drum itself, which sets the mode ratios and balance:
  • Frame — ideal circular membrane: inharmonic, indefinite pitch (frame

drums, hand drums).

  • Dayan — the high tabla: its loaded head tunes the overtones near-harmonic,

so it sings with a clear pitch.

  • Bayan — the low tabla: a deep, boomy bass drum, fundamental-heavy.
  • Tom — a tight, woody, pitched tom.
  • Conga — a bright single-headed hand drum with a slappy attack.
  • Tune — fundamental pitch, 40–400 Hz. The upper modes track it, so the whole

drum tunes together.

  • Pitch CV — attenuverter on the pitch input (the 1V/oct jack). +1 (default)

= full 1V/oct tracking; turn it down to scale the CV, or below 0 to invert it.

  • Decay — ring time, 0.05–4 s. Tight tom → booming frame drum.

TONE

  • Harm (Harmonicity) — pulls the mode ratios toward a pure harmonic series.

At 0 you hear the drum's natural overtones; turn it up to "tune" any model into a pitched, tabla-like ring.

  • Damp (Damping) — how much faster the high modes fade than the fundamental.

Low = long, shimmering, metallic; high = quick, dull, dry.

  • Glide — the tension pitch-glide ("boing"). A real struck head tightens on

impact and relaxes as it rings, so its pitch starts high and slides down — the signature of toms and timpani. At 0 the pitch is static (a pure resonator); turn it up for a deeper drop. The glide scales with how hard you hit (accent) and tracks the Decay time, and it's what makes a struck drum sound alive rather than like a tuned chime.

STRIKE

  • Pos (Strike Position) — center vs edge. Center (low) is round and boomy;

edge (high) is bright and ringy.

  • Pos CV — attenuverter on the pos input. +1 (default) = full; turn down

to scale, below 0 to invert.

  • Hard (Hardness) — soft, broad contact (a hand: dull, thuddy) vs a short,

sharp contact (a stick: bright, clicky, excites more overtones).

  • Accent — how much the accent input affects the hit. +1 (default) = full

velocity response; 0 = accent does nothing (every hit at unity); below 0 inverts it (a positive accent then plays softer).

OUTPUT

  • Sat (output saturator) — Clean (default) keeps musical-level hits in the

linear region, so the simultaneously-ringing modes don't intermodulate into a faint gritty haze; only true overload peaks are softly rounded. Warm is the original tanh voicing — a touch of analog compression/glue, but it colors the sound (that "gritty reverb"). Clean is a hair more dynamic, so accents pop a little louder; nudge Level if you want the two modes loudness-matched.

  • Level — output level.

Tips

  • No two hits are identical — the excitation has a noise component, so fast rolls

breathe instead of machine-gunning.

  • Tabla: pick Dayan, Tune ~190 Hz, short Decay; pair with a Bayan instance an

octave down for the classic two-drum sound.

  • Melodic toms: pick Tom, feed pitch from a sequencer, keep Decay short,

and a little Glide for the classic tom "dooowm."

  • Patch an envelope or random voltage into accent for natural dynamics, and a

slow LFO into pos to make a hand-drum part wander between center and rim.

  • Bayan glide: pick Bayan, patch a slow envelope (or pressure CV) into

bend to bend the pitch down then up under each stroke — the hallmark tabla bass gesture.