It must be a bug, a problem with note-off.
It's not a bug, it's simply a minor limitation of how it currently works.
In the vast
majority of situations, instantly cutting the volume of a playing sound to silence will result in a discontinuity and a nasty click.
Here I'm playing a simple bassline with a pure sinewave. The first bar is with volume ramping on the note off, the second bar is without volume ramping. The difference between them and problem I'm talking about should be immediately obvious. When volume ramping is disabled it sounds like total shit.
The problem that pat has encountered is a very specific case that reveals a minor flaw in the note off volume ramping.
It's an unfortunate problem, but you can work around it in a variety of different ways.
If you find yourself needing to repeatedly play a small portion of longer sample, you can simply cut that small portion out to a new sample and make your precise edits there instead.
You could also use slice markers on the longer sample, since Renoise will not perform any volume ramping when the end of a slice is reached. This would negate the need for note off commands altogether.
Some better control over the volume ramping in Renoise would of course be great, not just for note offs but for other thing like automating volume levels from the pattern or with meta devices. I would welcome the ability to increase or reduce its ramping amount, or to even disable it completely for certain situations. But for right now
, you'll simply have to live with it and find your own workarounds for these edge cases where its effects are not desirable.