Schlappi Engineering Three Body
Triple FPGA oscillator for phase and frequency modulation
30 HP Eurorack module
Three Body is a phase- and frequency-modulation toolkit built around an FPGA core that brings digital DDS techniques to an analog interface. It contains three oscillators — a left, a center and a right — that can run fully independently or use a web of internal normalizations to behave as a stereo FM voice, drone bank or noise box. Each oscillator has three state switches (Free/Ratio, Exp/Lin, and Hi-Mult/Low-Div) defining one of 8 states, plus volts/octave, phase and frequency modulation inputs and sine/triangle/saw/square outputs. The center oscillator adds two phase-modulation index inputs and a second pair of phase-related outputs (cosine and cosaw) for wide stereo imaging. High internal sample rate (12.5MHz audio path, 36-bit accumulator) gives clean audio-rate modulation.
Features
- Three independent oscillators (left, center, right)
- FPGA core with 12.5MHz audio path and 36-bit accumulator
- Phase and frequency (through-zero) modulation
- Each oscillator: V/Oct, phase and FM inputs
- Per-oscillator modulation index (VCA) CV inputs
- Sine, triangle, saw and square outputs on every oscillator (16 total)
- Center oscillator adds cosine and cosaw for stereo (phase-related pairs)
- Free-running or ratio-tracking mode per oscillator
- Exponential or linear through-zero FM per oscillator
- CV-controllable frequency ratios
- External tracking at a CV-controllable ratio via SYNC
- Extensive internal normalization for instant stereo FM / drones
Controls & Jacks (54)
- Left Coarse/Mult
- Left Fine/Div
- Left FM Index
- Left Phase CV
- Left Type
- Left FM Mode
- Left Range
- Transpose In
- Left V/Oct Ratio In
- Center Coarse/Mult
- Center Fine/Div
- Phase 1 Index
- Phase 2 Index
- FM CV
- Center Type
- Center FM Mode
- Center Range
- Center V/Oct Ratio In
- Right Coarse/Mult
- Right Fine/Div
- Right FM Index
- Right Phase CV
- Right Type
- Right FM Mode
- Right Range
- Right V/Oct Ratio In
- Left Phase In
- Left FM In
- Left FM Index In
- Left Sync In
- Center FM In
- Phase 1 In
- Phase 1 Index In
- Phase 2 In
- Phase 2 Index In
- Center Sync In
- Right Phase In
- Right FM In
- Right FM Index In
- Right Sync In
- Left Sine Out
- Left Triangle Out
- Left Saw Out
- Left Square Out
- Sine Out
- Cosine Out
- Triangle Out
- Saw Out
- Cosaw Out
- Square Out
- Right Sine Out
- Right Triangle Out
- Right Saw Out
- Right Square Out
How-To Guides
- Unmodulated harmonic ratios
- Phase modulation with ratios (stereo)
- Stereo linear FM
- External pitch tracking
- Clocked ratio bass
Explore the interactive Three Body panel on BleepDex — tap any control to learn what it does.
