Korg released the Poly-61 in 1982 and the Midi version ("61M") in 1984.
The Poly-61 was the successor to the Polysix. Both
are 6-voice synths but the Poly-61 has 2 oscillators per voice instead
of one.
Voice 1 is a true analog oscillator, digitally controlled, while voice 2 is a simple digital counter
that clocks at audio frequencies.
The Poly-61 has an x-y joystick instead of wheels for it's pitch bend and modulation
functions. It has the same arpeggiator feature as the Polysix.
The Poly-61 launched one-parameter-at-a-time data entry.
Three, 2-digit LED displays
are used to select program numbers, parameter numbers, and parameter values.
In this Repair Story, we tackle a unit that would only produce short, click-like
attack envelopes.
Attack and decay settings had no effect.
You'll see how to take apart the synth, troubleshoot the envelope circuits, and replace the bad parts.
