Ploytec (Ploytec.com) develops chipsets for USB MIDI and audio as well as the PL2, analog synthesizer module
The PL2 is an analog synthesizer module with a digital (125kHz, state variable) multimode filter, offering unique saturation. That filter's followed by a second analog lowpass filter. It comes in two versions:
The original black PL2 is MIDI powered via its MIDI input. It works with almost any MIDI equipped keyboard or MIDI interface. The built-in micro USB connector doesn't contain USB functionality, but can be used for additional power when needed.