After update from 2.3.7 to 2.4.0, on some note played via tuxguitar, a "larsen" is emitted shortly

[ycollet]

FluidSynth version

I used fuildsynth 2.4.0 from Fedora 41. The version before this update was 2.3.7.

Describe the bug

I used fluidsynth via tuxguitar.
When I play some guitarpro score, some some notes; a larsen is emitted briefly.
Seems to disappear if I turn off chorus and / or reverb.

Expected behavior

No audible larsen

Steps to reproduce

I haven't yet a good reproducer. I will pos one once I found a reproductible score

Additional context

There was no problems before 2.4.0. Tuxguitar was not updated in the mean time.
I removed the tuxguitar configuration and start a new one from scratch but the problem is still here.

[derselbst]

What do you mean by "larsen"? Also, I highly recommend to use fluidsynth 2.4.1 since we have fixed possible clicks and pops in the low pass filter. If it also happens with 2.4.1, pls. post at least an audio sample where the "larsen" can be heard, or even better, a reproducible score.

[ycollet]

I will wait for the fedora update.
From tiime to time, there is a high frequency sound really similar to a larsen we can hear with a guitar.
The problem is not always reproductible. Once I found a GuitarPro score where the problem occurs regularly, I will record the sound.

[ycollet]

Here is an example.

We can here the high frequency sound in the 2 first sequences.

output.mp4

[derselbst]

So, you mean that feedback that builds up on the right channel? To me, this sounds like a note that hasn't received a noteOff yet. I need a score or a MIDI file to investigate. With which version of fluidsynth did you produce this? Also, it would be helpful if you posted an example of what you would expect to sound it like.