Full polyphony: you can hit every single key on the board at the same time and a note will come out.
X voice polyphony: you can hit X number of keys at the same time and notes will come out. After that every extra key will only move voices around., you will never get x+1 sounds to come out.
Full poly is rare on an analog synth but common on a transistor organ. To understand why one has to understand the difference between a synth and an organ. (i didn’t until I bought this and saw the guts.)
basically a synth traditionaly has the same number of polyphony as oscillators. some, like the minimoog, use multiple oscillators per voice. So, what you end up with in an analog synth is the same number of complete mini-synth sound generation and shaping circuits as you have voices. A jupiter 8 had 4 boards, each with 2 synthesizers, for 8 voice polyphony.
A transistor organ takes a single oscillator and through the magic of transistors, IC’s chips and capacitors divides that out into all the notes on the keyboard.
So, opus3=organ with moog filters
jupiter 8= 8 synths in one box controlled by the same keyboard. Each finger gets a “mini synth.”
As to the voices thing, that term can be misused. Think of a voice on an organ as the same thing as a patch on a synth. On a synth people tend to use “voice” as a shorthand for mini synth typey thing that makes a noise when you hit a single key. Ergo two notes simultaneously requires two “voices.”
There are a whole lot more variations than this, but that is the very basic idea in a nutshell.
I am still learning all the ins and outs of the Opus 3, and am actually working on a string patch. Organ is the best by far though, as you can set it up so the organ goes to the output jacks raw, chorused, and VCO’d all together. Strings get chorus and that is it, no raw, no VCO, so it is a bit trickier. Makes a decent sound, but not like the organ and brass.
Mainly I posted the clip so others could decide for themselves if the opus had not a single good sound in it. I think it has the potential for many good ones, but with the caveat that it is not a synth, it is an organ with extras…
take care,
Jester