so im wondering what do the dc filter/dither/soft clipping buttons do in the configs panel in renoise.
i hear no difference…
and what would be the best setup for max performance?
Kcirr3d
noone? 
If you have samples with really terrible DC offsets, or perhaps you use a VST synth which introduces a big offset, the DC filter will attempt to fix that.
For example, it will try to turn this: (notice how the sound is way below the zero crossing line - nasty!)
Into this:
It doesn’t work exactly like this (these shots are from Soundforge), and it’s not totally perfect, but it helps. Of course the most important thing is just clean your samples first and try to take it easy with the crazy sounds.
Dithering only affects samples and helps to make them sound nicer when playing them at different pitches (ie. not their original pitch), smooths them out a little bit. This does not affect VST synths since they generate their own sounds. It can sometimes have a slight dulling effect on high frequency samples, high hats for example. If you think that some high frequency stuff is being affected too much then turn it off. I personally leave it on until I feel like I have a reason to turn if off.
And soft clipping is pretty much exactly what it sounds like. If you have a lot of sounds playing and the volume gets a bit too high, rather than completely clip them which sounds pretty harsh (basically distortion), soft clipping performs more of a wave shaping effect so the clipping gets slightly rounded edges to it. With soft clipping turned on you can really crank the sounds up without suffering too much from sound distortion.
As for performance, well I really don’t think you’ll suffer too much even with all of these options turned on. They don’t seem very cpu intensive in my opinion.
thanx for the great explanation…
exactly what i wanted to know. 
