XAOC Devices Batumi II
Quad LFO powerhouse from micro-slow to audio rate
10 HP Eurorack module
Batumi II is a quad wide-range voltage and tempo-controlled LFO offering four channels of modulation from ultra-slow to audio rates with V/oct tracking. It generates 12 simultaneous waveforms across four channels and operates in free, phase, divide, or mult modes for independent or synchronous multi-voice modulation. Its anti-aliased digital core with adaptive analog output filters gives it a smooth, organic character suitable as a central modulation hub for any modular patch.
Features
- Four channels of wide-range LFO from 9.76 microHz to 5.0kHz
- V/oct tracking throughout entire frequency range enabling VCO use
- 12 simultaneously available bipolar output waveforms (sine, asgn, rect per channel)
- Assignable waveform per channel: triangle, downward saw, upward saw, trapezoid, step random, smooth random
- Four operation modes: free, phase, divide, mult
- Per-channel reset and sync inputs responding to rising edges
- Two synchronization methods: reset and tap-tempo sync
- Anti-aliased digital waveform generation with adaptive analog output filters
- Frequency division factors: 1, 2, 3, 4, 5, 8, 16, 32
- Frequency multiplication factors: 1, 2, 3, 4, 5, 8, 16, 32
- Maximum frequency automatically reduced to stay below 5kHz in mult mode
- Phase mode enables FM-like timbres at audio rates via continuous CV modulation
Controls & Jacks (29)
- Slider A — Controls channel A frequency in all modes (0.01–100Hz, up to 5kHz with CV). V/oct tracking. Master tempo for phase/divide/mult modes.
- Slider C — In free mode: channel C frequency. In phase mode: C phase offset (0–360°). In divide/mult modes: C ratio factor (1–32).
- Slider D — In free mode: channel D frequency. In phase mode: D phase offset (0–360°). In divide/mult modes: D ratio factor (1–32).
- Mode LED — Shows current mode: red=free, yellow=phase, blue=divide, turquoise=mult. Blinks at threshold crossings.
- Sync LED — Shows sync method: unlit=reset, lit yellow=tap-tempo sync.
- Wave LED — Shows asgn waveform: red=tri, yellow=down saw, orange=up saw, green=trapezoid, blue=step-random, turquoise=smooth random.
- FRQ CV A — CV input for channel A frequency. V/oct tracking. -10V to +10V. Always frequency regardless of mode.
- FRQ·PH·RTO CV B — CV input for channel B. Function depends on mode: frequency/phase/ratio. -10V to +10V.
- FRQ·PH·RTO CV C — CV input for channel C. Function depends on mode: frequency/phase/ratio. -10V to +10V.
- FRQ·PH·RTO CV D — CV input for channel D. Function depends on mode: frequency/phase/ratio. -10V to +10V.
- Reset/Sync A — Reset or sync input for channel A. Rising-edge sensitive. In sync mode, sets master tempo for all channels.
- Reset/Sync B — Reset or sync input for channel B. Rising-edge. Tap-tempo sync only in free mode.
- Reset/Sync C — Reset or sync input for channel C. Rising-edge. Tap-tempo sync only in free mode.
- Reset/Sync D — Reset or sync input for channel D. Rising-edge. Tap-tempo sync only in free mode.
- Sine A — Bipolar sine wave output ±5V from channel A. Anti-aliased with adaptive analog filtering.
- Sine B — Bipolar sine wave output ±5V from channel B.
- Sine C — Bipolar sine wave output ±5V from channel C.
- Sine D — Bipolar sine wave output ±5V from channel D.
- ASGN A — Assignable waveform output ±5V from channel A. Waveform set by Wave button.
- ASGN B — Assignable waveform output ±5V from channel B.
- ASGN C — Assignable waveform output ±5V from channel C.
- ASGN D — Assignable waveform output ±5V from channel D.
- RECT A — Bipolar rectangular wave output ±5V from channel A. Cannot be attenuated.
- RECT B — Bipolar rectangular wave output ±5V from channel B. Cannot be attenuated.
- RECT C — Bipolar rectangular wave output ±5V from channel C. Cannot be attenuated.
- RECT D — Bipolar rectangular wave output ±5V from channel D. Cannot be attenuated.
- Slider B — In free mode: channel B frequency. In phase mode: B phase offset (0–360°). In divide/mult modes: B ratio factor (1–32).
- Mode — Cycles through modes: free→phase→divide→mult. Hold + Wave toggles sync method.
- Wave — Cycles asgn waveform: tri→down saw→up saw→trapezoid→step random→smooth random. Hold + Mode toggles sync method.
How-To Guides
- Four Independent LFOs from Scratch
- Quadrature LFO at 0-90-180-270 Degrees
- Clock-Synced Polyrhythmic LFOs
- FM Synthesis with Phase Mode at Audio Rate
- Four Uncorrelated Random CV Sequences
- Harmonic Series LFO Stack
- Phase-Reset Polyrhythmic Sequences
- Slow-to-Fast LFO Bass Modulation
- Temporal Fugue with Phase-Shifted Random Sequences
- Clock-Synced PWM with Rect Output
Explore the interactive Batumi II panel on BleepDex — tap any control to learn what it does.
