Envelope retrigger mode

[pawa75]

Expected behavior

If I play a note, with a sound that has a long release time, including the release time for the filter envelope. The filter envelope should start over for a new note on event on the same note, even if the filter envelope is not finished.

Actual behavior

The filter envelop won't start from the beginning when the same note is played over again, this occurs only with sounds with a long release time.

A sound example "Bomb sweep" nr 73 from my first bank:
https://drive.google.com/file/d/1PdDeGqspHXnW2UPvBe76cXBT-Wt6_kkf/view?usp=sharing

One more example when the filter sounds different when the same note is play over again with no gap in the sound vs when it's play after other note or silence, from my second bank "High Speed" nr 120
https://drive.google.com/file/d/1ZJF-JqrYvAoyxRHwZeT-lJVS9ZohZd8c/view?usp=sharing

Link to bank files: https://drive.google.com/drive/folders/17f_B0CSBcVxc0kaHv3om6jm088eDrifd?usp=sharing

Information

• Which version of amsynth are you using? 1.10.0
• Which build of amsynth are you using? stand-alone application
• If using amsynth as a plugin, which host application are you using?
• Which operating system & version are you using? Manjaro 20.0.3 and Fedora 32

Steps to reproduce the behavior

1. Start up qjackctl, start jack2, start Amsynth, connect midikeyboard
2. Select a sound with a long filter envelope, that has a long release time
3. Playing the same note before the filter envelop has finished, it does'nt if other notea is played inbetween, they start from the beginning of the filter envelope the first time, if they are played again whithin the release time, same thing happens, the envelop won't start from the beginning.

[nickdowell]

I think what you're describing is the intended behaviour...

• For a "fresh" note, the envelopes will start at 0 and ramp up to 1 according to the attack time.
• For a note that's still in the release phase, when retriggered the envelopes will ramp up from their "current" values to 1 without starting from 0 again.

Does that behaviour seem wrong?

Do hardware (analog) synths do it differently?

[nickdowell]

Found a reference that might be useful for discussing the behaviour.

amsynth operates like the "Multi-trigger" mode for poly and mono keyboard modes, and "Single-trigger" when keyboard mode is set to legato.

[pawa75]

Thanks for your explanation. Then I know that it's an expected behavior. To simulate some instruments, like a guitar, you could play the same note but on two separate strings, the envelope needs to start all over from the beginning. I've used digital synths before and they only retrigger i polyphonic mode, so I'm not used to this :). But maybe it's usefull in some ways.

[nickdowell]

I can see usefulness of Retrigger mode... I need to investigate some other synths to better understand how it should work; the feature could potentially be added to amsynth.