The amount and tone of the effect is set with the comp / lo-fi parameter which simultaneously compresses the signal and dampens it in the high frequencies by a low pass filter. The more you turn up the potentiometer the more damp and "older" the sound gets, resembling an old audio tape with saturation, like said before.
The modulation oscilator has potentiometers and CV inputs for controlling the frequency and the modulation intensity. The waveform is selectable between sine, triangle and square.
In addition to the internal LFO you can use an external modulation signal which is patched to the ext socket and mixed with the LFO waveform.
Even the dry/wet mix between the clear original signal and the compressed lo-fi effect signal can be modulated by a CV at the d/w input - way better than an ordinary bypass switch.
audio input, audio output, input for external wave
CV inputs: compressor/lo-fi, speed, depth, dry/wet mix
3U Eurorack module, 10HP wide, 26mm deep
current draw: 85mA at +12V and 50mA at -12V