- the PPG Wave plugin has no single trigger mode for the envelopes, therefor
  the filter envelope is retriggered by every note
- only the Moog Prodigy can’t transmit velocity, in the other examples you can
  hear that velocity modulates filter cutoff
- the Pulse envelopes aren’t as fast as the envelopes of the others
- now that you have identified three of the synths, the rest should be easy:
  microQ and Virus have completely different filter characters ;-)