I work alot with my 303 and have, for the past two years, worked with various pedals and distortion boxes to get the sounds I desired. I have recently tried demos of amplitube and downloaded some free amp sims like X-amp and jcm-900. I indeed get my desired sound, josh wink - higher state/prodigy - voodoo people like, but unlike josh winks track with the tweaking cutoff, when i raise my cutoff with any of the above plugs the squelch is replaced by a lofi buzz and the higher the cutoff the less resonance is heard. Is there a reason for this?

Thanks
Rob

Filter resonance lives with (consists of) high peaking transients, which form that characteristic timbre.

Amp sims (there are very different working models) cut or (heaviely) modify the signal, especially where the resonance timbre character is.

Whatsoever, there are some overdrive or distortion effects, which maintain the resonance character more or less.

I know this, because I developed several TB 303 clones and it was very difficult to find good distortion and/or overdrive effects to maintain the resonance charakteristic of the 18db resonance filter of that bass synthesizers as much as possible.

Trial and error is the key. And often also the taste.

.

Thanks for the reply. I noticed that the bloodoverdrive, though not an amp sim, held that resonant character as the resonance would maintain its integrity whilst the cutoff was at its peak position, yet other distortion, with the 303 filter turned all the way down, sounded great until the filter was tweaked up. I will take your advice and try many distortions with this new knowledge.

Cheers