ACL QLFO is an LFO module for modular synthesizers in Eurorack format. The module is a so-called CV-controllable quadrature oscillator, which can be used as an LFO, but also as an audio oscillator due to the 1V/octave input. It generates a sine, cosine and two phase-shifted copies of the waveform in parallel. The frequencies can be controlled manually or by control voltage and the frequency range extends from below one Hertz to the audio range, for which the range is switched over three ranges. For CV control there is an input with attenuator and an input adjusted to 1V/Oct for control with key CV.