The Max / Min is a much underrated audio tool.
The A-102 is a 24 dB lowpass which uses diodes (and not transistors), which leads to quite unusual resonance behaviour (resonance is dependant on filter frequency). The filter can easily be overdriven, which adds some interesting harmonics.
The A-111-5 is a “Dark Energy” in Eurorack format (without Midi and wooden side panels). This is a nice and versatile module: quick sound changes are possible without patch cords, overall sound is very good and the filter will follow 1 V / octave extremely well, thus being something like a “second VCO” when self oscillating.
This is one of Doepfer’s older filter designs, nonetheless it is quite an interesting one. It offers four filter modes: Notch – Highpass – Bandpass – Lowpass, each with a separate output (so you may use it together with a switch or a voltage controlled mixer).
The A-118 is an analog noise generator which can produce continuous random voltages as well. Easy to use and quite versatile.