When Roland released the CMU-810 in 1983, they created something genuinely unusual: a desktop synth expander that borrowed the tone generator from their legendary MC-202 but stripped away the sequencer, replacing it with a flexible audio mixer instead. It was designed as part of the "Compu Music" series to work with the CMU-800 computer system, though only about 30 units were made for the Japanese market, making it one of Roland's most obscure creations.
The CMU-810 is a compact monophonic analog synthesizer with a single voltage-controlled oscillator offering sawtooth, square, and pulse waveforms plus a sub-oscillator tuned an octave below. The 24dB resonant low-pass filter responds to both envelope and LFO modulation, while the ADSR envelope can operate in linear or exponential modes. An LFO provides modulation sources for pitch, filter cutoff, and pulse width, and there's portamento for smooth pitch transitions. The real standout is the built-in audio mixer with two external inputs and a voltage-controlled amplifier that lets you blend external sources before the final output, making it function as both a sound source and a processing hub.
Physically, it's a desktop unit measuring just 343mm wide and 55mm tall, weighing only 1.35kg, so it fits easily into tight studio spaces. All control happens via CV and gate inputs—there's no keyboard, which means you need an external sequencer, MIDI-to-CV converter, or control voltage source to play it. The headphone output makes it convenient for monitoring, and the whole thing runs on either batteries or a 9-12V DC power supply.
The CMU-810 has developed a quiet reputation among those who've found one. It delivers the same warm, characterful bass and lead tones as the MC-202 and SH-101, and because it's relatively unknown compared to those classics, it often costs significantly less on the used market. The mixer section adds practical flexibility that the MC-202 lacks, and the CV-only design, while limiting for casual use, makes it a powerful tool for modular setups and computer-controlled synthesis. It's the kind of gear that rewards patience and experimentation rather than immediate gratification.
