Not sure if anyone has tried this out yet, but I’ve been playing around with some (albeit limited) polyphony on my modular through the A4.
For functional duophony
Poly enabled tracks 1 & 2
CV A/B set to pitch/gate respectively and sourced from track 1
Same again with CV C/D sourced from track 2
Send each CV pair to a separate OSC>Filter>VCA
Send keyboard midi in to either poly track
Unfortunately none of my filters are a matched pair so exact mirroring of voices isn’t perfect, but the idea is there.
Alternatively, for slightly dysfunctional chord stabs or pads, you can run 3 oscillators through a single filter>VCA
Poly enabled tracks 1,2 & 3
CV A/B/C all set to pitch, sourced from tracks 1-3 respectively.
CV D set to gate, sourced from any poly track.
A/B/C send to Oscillators
D to ENV>VCA
Midi in to any one of the allocated poly tracks.
I found sending the midi in to the gate track perhaps the best way to go.
Note: This is where it gets a bit clumsy. Depending on how voice stealing/allocation is set, and I believe, which track you are sending midi to/sequencing/playing the mini keys on, you will have different results in how your envelope is triggered and potentially accidentally cut off if you hit more than 3 keys at once. Experiment to suit your playing style.
Also this is only really an issue if you say want to hold one or two notes as a drone and then play around melodically with the third.
For simple triads, as long as only 3 notes are hit at the same time, I don’t think it matters where the gate is coming from, one of the tracks will always trigger your envelope.
Hope that all makes some sort of sense.
Anyway, it’s something fun to play around with, and I think the chords from the modular sound pretty incredible. Makes me wish there were a whole lot more than just 4 CV outs now