The Poly-61 marked a significant departure in design philosophy from previous Korg synthesizers by replacing the traditional array of dedicated control knobs on the front panel with a digital interface that required users to select parameters individually for adjustment.

[1][2] In 1984, an updated version, the Poly-61M, was released to incorporate support for the newly established Musical Instrument Digital Interface (MIDI) standard.

The voltage-controlled filter (VCF) includes standard controls for cutoff frequency, resonance, keyboard tracking, and envelope modulation.

[1] The audio signal path passes through a voltage-controlled amplifier (VCA), which can controlled via an ADSR envelope generator or an external CV/gate pulse.

The synthesizer's low-frequency oscillator (LFO) produces a triangle wave, featuring a variable delay, and can modulate both the DCOs and the VCF.