For sale is a working Maestro Ring Modulator, model RM-1 (not RM-1A or RM-1B) from the date codes on the ICs, it appears this unit was manufactured in 1971. Sliders are clean but not smooth. This unit has a single pedal input, ext. carrier and instrument inputs, oscillator output, and modulation output. You can bypass the modulation with a switch, and with another switch select between two ranges on the internal oscillator.
This is THE classic Ring Modulator effects pedal, and this is a super rare early model (I can’t even find any photos online of the RM-1 with the single pedal input like this one). I made a short video to demonstrate that this is working, with an ARP Omni 2 of all things….
International buyers please contact me before ordering this product, the shipping calculator will not be correct.