Prototype of the MOTM-440 module, hand-built by Juergen Haible. The production version is part of the Synthesis Technology MOTM Analog Modular Synthesizer system. It's a discrete clone of the SSM4040 (IC) filter. It sounds great and has wonderfully aggressive overdrive. I had it in the studio, patched into my larger MOTM system, in order to record audio demos for Synthesis Technology.