This is a beautiful 24dB filter with a brilliant and somewhat rough sound, quite different from the A-108 Transistor Ladder. For technical details, please see Doepfer’s Homepage:
This example uses three A-110 VCOs (sawtooth, one VCO is tuned down 1 oct), cutoff frequency is modulated by an Envelope Generator and the A-155 sequencer (same track that controls VCO pitch), Resonance (called „Q“ here) is controlled by a second A-155 track. Btw., the examples here are not intended for some kind of „scientific“ comparison between modules. On the contrary, I would like to show some characteristics in a somewhat musical context.
Here we go:
Since the A-105 allows for some nice overdrive, we increase the input volume during the track.