Module A-143-3 is a low-cost four-fold modulation oscillator, often called LFO (low frequency oscillator). Like the other modules of the A-143 series (A-143-1 and A-143-2) not a very "exciting" module, just a bread-and-butter device and a simple demon for work.

The module contains four simple LFOs. Each LFO is equipped with three waveform outputs: triangle, rectangle and sawtooth. The frequency of the sawtooth output is twice the frequency of the other outputs. A three-way switch is used to select one of three frequency ranges mid-low-high, spanning from about two cycles per minute at the lowest, to moderate audio frequency at the highest (about 5 kHz).