On Virta 1.31 / Windows 10 64bit / Ableton Live 9.7 64bit
When I'm playing with a patch and feeding Virta a MIDI sequence, both from the Max for Live mono sequencer and just plain MIDI clips, I notice that if I change the number of voices to over 1, and switch on unison, the incoming MIDI seems to get stuck and no note messages reach the "gate" output. The sound comes back if I then change the number of voices down to 1 and switch off unison. If all voices are playing and unison is switched off, behaviour is as expected.
This was originally with my own preset, but I found the same thing to happen when I used the comb organ preset.
Thanks for the great sounds!
Thanks for the report, I'll try to duplicate this.