update 090811: thanks to batuhan bozkurt for putting me straight. it's not an intel vs ppc issue but rather apple changed something in their internal soundcards. using a newer (intel) machine and an external soundcard (fireface 400), the punk code sounds the same as the ppc version below (ie good/better in my ears - no autocompression).
so the internal soundcard in my old powerbook (1ghz, ppc) is robust, filters hardly ever blows up and it doesn't have that automatic compressor/limiter as my newer macbook pro (2.16ghz duo, intel) internal soundcard.
something i knew all along but tried to ignore: many of my noisier synths sounds like crap on modern (intel) macintoshes and some even goes all silent. the code below deliberately blows up a resonant hipass filter and is typical for how different the same code can sound on my intel vs my ppc mac. listen to the attached mp3 files. in a few years all the ppc computers will be gone and we can't recreate the sounds.