Knobula Drum Farm
Three-voice drum machine, sampler and FX engine on one screenless 24HP panel.
24 HP Eurorack module
Drum Farm is a complete drum voice for Eurorack with three independent sound sources — a 16-model drum synth, a 16-slot sampler with two players, and a 16-effect stereo FX engine — all controlled by knobs whose icon rings replace any menu or display. Every voice has its own Decay, Pitch and trigger, plus a Shift-button system that exposes a second function on virtually every control (Gain, Accent, Erase, Set/Insert, Save). The sampler captures audio in real time from the Ext In, slices it across 16 slots per bank, and lets you build kits on the fly with the Get/Get All/Set/Insert workflow. Assignable Trig A/B and CV A/B/C inputs are bound to any control by patching a cable and touching the destination within two seconds.
Features
- 24HP all-in-one drum module with three independent voices
- 16 hand-tuned drum synth models selectable via icon-ringed rotary
- Two-knob (X/Y) macro control per model — no menus or screens
- 16-slot sample player (Player 1) with Decay, Pitch, Gain, Accent
- Independent second sample player (Player 2) with Link option
- Live sampling from Ext In with ON / AUTO / OFF record modes
- Get / Get All / Set / Insert / Swap workflow for fast kit building
- 16 user banks plus 16 factory ROM banks (User/Rom switch)
- 16 stereo effects with always-on Reverb and Echo
- Two-knob (FX 1 / FX 2) macro control per effect
- Side Chain effect with built-in kick-keyed compressor
- Five assignable inputs (Trig A/B + CV A/B/C) via touch-to-assign
Controls & Jacks (44)
- Player 1 Decay — Sample envelope decay time for Player 1; Shift sets per-voice gain.
- Player 2 Decay — Sample envelope decay time for Player 2; Shift sets per-voice gain.
- Drum Synth Decay — Amplitude envelope decay for the synth voice; Shift sets gain.
- Player 1 Pitch — Sample pitch (±1 octave by default); Shift sets accent amount.
- Player 2 Pitch — Sample pitch for Player 2; Shift sets accent amount.
- Drum Synth Pitch — Pitch of the synth voice; Shift sets accent amount.
- Drum Synth Model — 16-position rotary that selects one of the 16 drum synth models. Icons on the silkscreen ring identify each voice.
- X — Primary macro for the active drum synth model. Function changes per model (tone, body, snap, etc.).
- Y — Secondary macro for the active drum synth model. Function changes per model (noise, sustain, character, etc.).
- FX Select — 16-position rotary choosing the effect inserted across the stereo bus. Reverb and Echo are always-on; positions 3–16 select the additional e
- FX 1 — Primary parameter for the selected effect (rate, depth, amount).
- FX 2 — Secondary parameter for the selected effect (tone, mix, feedback).
- Bank Select — 16-position rotary (A–P) selecting one of 16 sampler banks. Each bank holds 16 sample slots.
- Sample Select — 16-position rotary picking which of the 16 slots in the active bank Player 1 (and linked Player 2) plays.
- Preview — Auditions the currently selected sample. Shift+Preview normalises the sampler buffer.
- Back — Steps the audition cursor one buffer back. Shift+Back erases the buffer (press twice to erase and roll buffers up).
- Fwd — Steps forward through the audition buffers. Shift+Fwd resets the cursor to buffer 1.
- Rec — Three-position record mode: ON arms continuous capture, AUTO arms threshold-triggered capture, OFF disables sampling.
- Load Bank — Loads the bank pointed to by Bank Select into RAM. Shift+Load Bank saves the active bank back to storage.
- User/Rom — Slide switch selecting whether Bank Select reads from the user (writable) bank pool or the factory ROM pool.
- Player 1 — Manually fires the Player 1 sample. Long-press toggles random sample selection on each trigger.
- Mute/Trig — Routes Player 1 audio to the main bus (TRIG) or mutes it while still firing the envelope (MUTE).
- Player 1 Get — Tap = Get (load the previewed buffer into the active sample slot). Long-press = Get All (load the buffer plus its 15 chops across the bank).
- Player 2 — Manually fires the Player 2 sample. Hold 2 seconds to route the Ext In through Player 2's envelope.
- Link — Slide switch that links Player 2 to Player 1 (shared sample/decay/pitch) or runs Player 2 as an independent voice.
- Player 2 Get — Tap = Get (capture buffer into Player 2). Long-press = Swap Player 1 and Player 2 samples. Shift+tap = Insert (paste buffer at current slot,
- Player 1 Out — Two-position switch sending Player 1 audio to Main or Aux output.
- Player 2 Out — Two-position switch sending Player 2 audio to Main or Aux output.
- Drum Synth — Manually fires the Drum Synth voice using current Model / X / Y settings.
- Load Session — Loads a full session (banks, models, FX, assignments). Shift+Load Session saves the current session.
- Shift — Modifier button. Hold while turning a knob or pressing a button to reach its silkscreened secondary function.
- Effects Out — Three-position switch routing the FX engine to Main, Aux, or Off (FX bypassed).
- Trig A In — Assignable trigger input. Patch a cable then touch any control within 2 seconds to assign Trig A to it.
- Trig B In — Assignable trigger input. Patch and touch a control to assign Trig B.
- Player 1 Trig In — Trigger input that fires the Player 1 sample voice.
- Player 2 Trig In — Trigger input that fires the Player 2 sample voice (or both, if Link is engaged).
- Drum Synth Trig In — Trigger input that fires the Drum Synth voice.
- Main Out — Main audio output (full module mix unless individual voices are routed to Aux).
- Ext In — External audio input. Routed to the sampler for recording or, with Player 2 held, through the Player 2 envelope.
- Rec Trig In — Trigger input that starts a sample capture (when Rec is ON or AUTO).
- CV A In — Assignable bipolar CV input. Patch and touch a control to assign CV A to it.
- CV B In — Assignable bipolar CV input. Patch and touch a control to assign CV B to it.
- CV C In — Assignable bipolar CV input. Patch and touch a control to assign CV C to it.
- Aux Out — Auxiliary audio output. Voices set to AUX appear here; useful for parallel processing or separate stems.
How-To Guides
- Build a 16-step kit on the fly
- Stacked snare with parallel reverb
- Generative percussion patch
- Sidechain duck with built-in compressor
- Resample a performance into a fresh kit
Explore the interactive Drum Farm panel on BleepDex — tap any control to learn what it does.
