ALM Busy Circuits Pip LFO
Compact 4HP all-analogue LFO with simultaneous bipolar/unipolar outputs and an audio-rate VCO mode.
4 HP Eurorack module
The Pip LFO (ALM048) is a compact 4HP all-analogue low-frequency oscillator from ALM Busy Circuits. A single Freq knob plus CV input sweeps the rate from roughly 0.01Hz (90s cycle) up to 30Hz, and a momentary VCO button retunes the core into audio range where it tracks 1V/oct over approximately five octaves. Square, sawtooth, triangle and sine waveforms appear simultaneously on dedicated jacks; saw, triangle and sine each provide both a bipolar +/-5V output and a unipolar 0-5V output, while the square wave is unipolar 0-8V. A Reset input restarts every waveform cycle and doubles as a hard-sync input in VCO mode, so the same module is equally happy as a slow modulator, a clock-locked rhythmic LFO or an oscillator.
Features
- Compact 4HP all-analogue LFO/VCO from ALM Busy Circuits
- Manual Freq knob plus dedicated CV input
- LFO range approximately 0.01Hz (90s cycle) to 30Hz
- VCO mode reaches audible frequencies and into the ultrasonic
- 1V/oct tracking over ~5 octaves in VCO mode
- Simultaneous square, saw, triangle and sine waveform outputs
- Saw, triangle and sine each provide bipolar (+/-5V) and unipolar (0-5V) jacks at the same time
- Square wave is unipolar 0-8V (higher peak than the other unipolar outputs)
- Reset input restarts all waveform cycles in LFO mode
- Reset input doubles as a hard-sync input in VCO mode
- Yellow VCO mode LED
- Red rate LED flashes at the oscillator frequency
Controls & Jacks (13)
- Freq CV In — CV input that adds to the manual Freq knob setting. In VCO mode tracks 1V/oct over ~5 octaves.
- Reset — Trigger input that resets all waveform outputs to the start of their cycle. Acts as hard sync in VCO mode.
- Freq — Manual LFO frequency control. Range approximately 0.01Hz (90s cycle) to 30Hz (0.03s cycle) in LFO mode; jumps to audio range in VCO mode.
- VCO LED — Yellow LED that lights when VCO mode is engaged, indicating the oscillator is running at audio frequencies.
- VCO — Toggles VCO mode. When engaged the oscillator runs at audible frequencies and tracks 1V/oct via the Freq input over approximately 5 octaves.
- Rate LED — Red LED that flashes at the LFO frequency, providing a visual indication of the current rate.
- Square Out — Unipolar square wave output, 0V to +8V. Note this output is unipolar only, unlike the other waveforms.
- Saw Out — Bipolar sawtooth output, oscillates between -5V and +5V at the LFO frequency.
- Saw Out + — Unipolar sawtooth output, oscillates between 0V and +5V at the LFO frequency.
- Triangle Out — Bipolar triangle output, oscillates between -5V and +5V at the LFO frequency.
- Triangle Out + — Unipolar triangle output, oscillates between 0V and +5V at the LFO frequency.
- Sine Out — Bipolar sine output, oscillates between -5V and +5V at the LFO frequency.
- Sine Out + — Unipolar sine output, oscillates between 0V and +5V at the LFO frequency.
How-To Guides
- Slow modulation
- Audio-rate drone voice
- Clock-synced rhythmic LFO
- Hard-synced VCO timbre
- Two Pip LFOs for complex modulation
Explore the interactive Pip LFO panel on BleepDex — tap any control to learn what it does.
