Modular Hybrid Rack

This rack makes the eurorack case and the TD-3 behave like any other Live instrument: play it from a clip or Push, control its knobs from macros, record it with the rest of the set and keep it sample-aligned. The CV Tools pack (free, Max for Live) is the glue: CV Instrument turns MIDI notes into calibrated pitch CV + gate through a DC-coupled interface output, CV Triggers fires drum triggers from a Drum Rack-style pad layout, CV Clock Out keeps the case locked to Live's transport, CV Utility turns macro knobs into static or scaled CV, and CV Envelope Follower brings the case's dynamics back as modulation inside Live. External Instrument and External Audio Effect handle MIDI/audio I/O with latency compensation. The reference case here: Buchla 258t clone (dual complex oscillator), Bastl Pizza (FM/phase oscillator), Bastl Ikarie (stereo filter), Qu-Bit Nautilus (delay), Mojave (granular) and Data Bender (buffer mangler), plus a Behringer TD-3 on MIDI. Genres: techno, acid, industrial, dub, ambient — anywhere a hardware voice should sit inside a Live arrangement without a separate recording session.

Requirements before you build

DC-coupled outputs. CV Instrument, CV Utility, CV Clock Out and CV Triggers write CV as audio to interface outputs. Most interfaces have AC-coupled outputs (a high-pass that kills steady voltages), so pitch CV from them sags back to zero. You need DC-coupled outputs: Expert Sleepers ES-8/ES-9/ES-3, MOTU UltraLite/828 series, some RME outputs. ±5 V from an interface at 0 dBFS is typical; the 258t and Pizza track 1 V/oct over roughly 5 octaves from that. Gates and triggers tolerate AC coupling for a few hundred ms but do not rely on it. The CV Envelope Follower and CV In directions (case → Live) work on any input as long as you accept an AC-coupled input will see slopes, not levels — DC-coupled inputs (ES-8/ES-9) are needed for real CV in.

Latency. Every device here has a hardware latency field. Set the interface buffer to 64 or 128 samples, then measure: Live's Preferences → Audio has a Driver Error Compensation; External Instrument and External Audio Effect have per-device Hardware Latency. Measure once with a click sent out and recorded back (see hardware & modular integration) and enter the value in every External device so the Delay Compensation engine aligns them.

Layout

How it's built

1. In Preferences → Audio, enable the interface's extra outputs and inputs (ES-8: outs 1–8, ins 1–4 plus ADAT). Set buffer to 128 samples. Add an Instrument Rack on a MIDI track, name it "Hybrid Modular", and create five chains: 258t voice, Pizza FM, TD-3, CV control, Case FX return.
2. 258t voice chain: add CV Instrument. Pitch output: ES-8 out 1. Gate output: out 2. Patch out 1 → 258t 1V/oct input, out 2 → the envelope's gate input (or the 258t's own gate if you use a low-pass gate). Audio in: ES-8 in 1/2 from the voice's output. Press the device's Calibrate: it sends a series of voltages, listens on the audio input and builds a pitch map for that oscillator — do this with the oscillator patched straight into the input and the audio chain dry. Hardware Latency: enter your measured value (e.g. 3.1 ms).
3. Set CV Instrument's Glide to 0 and its pitch range so C3 lands at the oscillator's middle; use the device's Transpose if the 258t sits an octave low. Add EQ Eight HP 30 Hz (Buchla-style oscillators drift below 20 Hz when FM'd) and Saturator Soft Sine 2 dB. Key zone C0–C6, velocity full.
4. Pizza FM chain: second CV Instrument on outs 3/4, audio in 3/4. Calibrate separately — Pizza tracks differently from the 258t. Utility after it. Key zone C2–C7, chain-select zone 64–127. Patch Pizza's FM input from the 258t's second oscillator for cross-modulation; with both chains under one key, a single note plays the carrier and the modulator at calibrated pitches.
5. TD-3 chain: External Instrument. MIDI To: the TD-3's USB port, channel 1 (set the TD-3 to MIDI channel 1 in its config). Audio From: ES-8 in 5 (TD-3 line out). Hardware Latency: measured (around 2–3 ms for the TD-3's analog path plus interface). Gain 0. Then EQ Eight HP 40 Hz and Compressor 4:1, Attack 2 ms, Release 60 ms, Dry/Wet 60% for parallel squash. Key zone C0–C4, chain-select 0–63, volume −3 dB. TD-3 responds to velocity ≥ 100 as accent and to overlapping notes as slide, so Note Length and Velocity MIDI effects before the rack control its articulation.
6. CV control chain: volume −inf (it makes no sound). Add CV Utility with four outputs: out 5 → Ikarie cutoff CV, out 6 → Nautilus time CV, out 7 → Mojave position CV, out 8 → Data Bender bend/repeat CV. Set each output's range (−5 to +5 V or 0 to +5 V) and leave Offset at 0. These four are the macro targets.
7. Add CV Clock Out: 16th-note clock on a spare output, run/reset on another if the case has a sequencer or clocked delay (Nautilus can sync to clock for tempo-locked repeats). Set the clock "ahead" offset to your round-trip latency so the case's clock lands on Live's grid. If outputs run short, choose: either Data Bender CV or clock on out 8 — the layout note above assumes clock takes priority when you sync.
8. Add CV Triggers with four trigger outputs mapped to MIDI notes C1–D#1 (its pad-style layout). Patch a trigger to Data Bender's "bend" trigger input and one to Mojave's freeze. A MIDI clip on this track with notes at C1 now fires hardware events on the grid, latency-compensated.
9. Case FX return chain: External Audio Effect. Audio To: ES-8 outs 9/10 (via ADAT expansion) → Ikarie input; Audio From: ES-8 ins 7/8 ← Ikarie output (or Nautilus after Ikarie). Hardware Latency measured. Dry/Wet 100% so the chain is the processed version; this chain receives the rack's MIDI but holds no instrument — it hears nothing unless you feed it. To process the hardware voices through the case filter, route the voice chains' audio to this chain: simplest is to make the Case FX return a separate Audio Effect Rack after the Instrument Rack rather than a chain (variation below). Keep it as a chain only if you insert an instrument before it.
10. Add CV Envelope Follower after the External Audio Effect, listening to ES-8 in 7 (the Ikarie return). Map its output to the Space macro's Hybrid Reverb Dry/Wet at 30% depth: the louder the filter resonance screams, the more reverb it gets. Hybrid Reverb Dark Hall, 15% wet.
11. Enter Map mode. Cutoff → CV Utility out 5 voltage −5 → +5 V. Delay time → out 6 −5 → +5 V. Grain pos → out 7 0 → +5 V. Bend → out 8 0 → +5 V. Each macro is now literally a voltage. Check the module's CV input range in its manual: Ikarie and Nautilus accept ±5 V; Mojave and Data Bender prefer 0–5 V on most inputs.
12. Voice → Chain Selector 0 → 127. Glide → both CV Instruments' Glide 0 → 300 ms. Drive → Saturator Drive 0 → 12 dB and TD-3 chain Compressor Dry/Wet 0 → 100%. Space → Hybrid Reverb Dry/Wet 0 → 50% and External Audio Effect Dry/Wet 100 → 60% (less wet case processing as the reverb comes in). Exit Map mode.
13. Randomization: exclude Voice and Cutoff (a random −5 V on the filter is silence; a random voice swap mid-phrase drops notes). Randomize Grain pos, Bend and Delay time freely — that is what the modules are for.
14. Macro Variations: "Acid" (Voice 20, Glide 0, Drive 70, Cutoff 40), "Buchla" (Voice 90, Glide 30, Space 40), "Bender" (Bend 100, Delay time 70, Grain pos 50).
15. Latency check: record a 16th-note MIDI clip through each chain to an audio track and compare against a Live kick. Adjust each Hardware Latency until the transients line up within a sample or two; CV Instrument has its own latency field separate from External Instrument.
16. Freeze is not available on tracks with External devices (they are real-time I/O), so when a part is done, record it (Resampling or a direct audio track) and disable the rack — see resampling workflow.

Macro map

Signal flow notes

Why CV Instrument instead of External Instrument + a MIDI-to-CV module: CV Instrument knows the latency of the audio output and input together and reports it to Live's delay compensation, and its calibration corrects the oscillator's tracking error per note. A MIDI-CV module adds MIDI jitter (around 1 ms) and no calibration. Use External Instrument only for MIDI hardware like the TD-3.

Why CV Utility for macros: a macro mapped to CV Utility is a sample-accurate voltage, automatable from clip envelopes, randomisable and recallable with Macro Variations — the module's own knob cannot do any of that. The reverse direction (CV Envelope Follower, CV In) lets the case modulate Live devices, so a Buchla LFO can drive a Live Auto Filter.

Variations

Case FX as a separate Audio Effect Rack

Move External Audio Effect + CV Envelope Follower + Hybrid Reverb into an Audio Effect Rack after the Instrument Rack. Now every voice goes through Ikarie and Nautilus, and the Audio Effect Rack gets its own macros (Ikarie Wet via External Audio Effect Dry/Wet, Nautilus feedback via a CV Utility out). This is the cleaner build; the single-rack version above exists so one preset recalls everything.

Drum case

Replace the voice chains with a Drum Rack whose pads are CV Triggers outputs (one trigger per pad to Data Bender, Mojave, and two 258t gates). Add CV Clock Out at 1/16 with reset to drive a Rotating Rhythm Generator (also in CV Tools) for euclidean variations inside Live and the case's own sequencer in sync. See hats & percussion.

TD-3 on CV

The TD-3 has CV/Gate inputs: patch CV Instrument out 1/2 to them instead of MIDI. You gain calibrated tracking and sample-accurate timing, you lose accents (TD-3 accent is MIDI/sequencer only). Add a CV Utility output to the TD-3's filter if you have modded one; otherwise keep MIDI for acid and CV for melodic lines. See acid rack.

Feedback case

External Audio Effect send to Data Bender → Ikarie → back, with Hybrid Reverb in the return and a Live Roar in Feedback routing after the return. The Space macro also raises Roar feedback. Dangerous and great for industrial; see feedback rack and no-input feedback.

Performance notes

• Push: the eight macros are on the encoders; Cutoff and Delay time are the live ones. Lock the rack to Push. Voice switching from Push is a hard swap, so do it between phrases. Push's pads play all chains according to key zones.
• Live tweaks: for acid, turn Glide to 0 and let Note Length (set to 110% in a MIDI effect before the rack) create TD-3 slides on consecutive notes. Automate the Bend macro with a Follow-Action clip for random Data Bender hits that still obey quantisation.
• Automation vs CV: automate macros in Session clip envelopes, not the CV Utility device directly, so moving a voltage to another output does not lose the automation. For audio-rate modulation, patch inside the case — Live's CV outs are fine for slow control but a CV LFO above 50 Hz through an interface output is band-limited and phase-shifted.
• CPU and latency: M4L devices are light, but every External device adds the round-trip delay to the track; with 128 samples at 48 kHz expect 5–8 ms total, compensated against other tracks but still felt on the keys. Drop to 64 samples when playing live, go back up to render.
• Checklist: interface outputs DC-coupled, calibrations saved with the set, Hardware Latency measured, CV Clock ahead set, and a mono check on the Pizza/258t cross-FM (FM through two separate inputs can introduce phase offsets).

Related

• Hardware & modular integration
• Modulation & Max for Live
• Routing & resampling
• Acid 303
• Acid rack
• Feedback rack
• Performance & live
• Industrial techno