alm-busy-circuits-pip-lfo

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.

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