Used Moog MF-102 in very good condition, includes PSU, but no box.
About the MF-102:
The MF-102 Ring Modulator is a direct descendant of the original Moog modular synthesizers. It contains three complete modular functions: a ring modulator, a voltage-controlled carrier oscillator, and voltage-controlled dual-waveform LFO. It can be used to process any instrument-level to line-level signal.
A ring modulator produces sum and difference frequencies between the audio input and a carrier oscillator. The ring modulator's LFO can be used to modulate the carrier frequency. The moogerfooger ring modulator can create effects ranging from subtle tremolo to harmonically rich distortion, gong-like sounds, sweeps, swoops, and divebombs. It can be subtle, or outlandish in it's use - you decide!
The moogerfooger ring modulator's control parameters are signal mix, carrier frequency, LFO rate, and LFO amount. All of the ring modulator's parameters can be controlled by the great feeling knobs that beg to be tweaked as well as with expression pedals or external control voltages. Panel switches select LFO waveform and carrier frequency range. 1/4" jacks are provided for audio input and output, pedal/control inputs, carrier input and carrier output. The heavy-duty yet smooth acting bypass switch allows tabletop or floor use.
Imagine that the ring modulator's carrier oscillator is producing a 500 Hz sine wave, and your input signal is a 100 Hz sine wave. The ring modulator's output will be a complex waveform. You will hear two pitches: 400 Hz and 600 Hz. You will not hear your original input or the carrier oscillator.