Thank you for the replies :) It seems I do need to just try out both chips for myself, and make a decision from there. And it seems like its a bit harder to get a solid 6581, so I think I will try the 8580 first. I am also going to hunt down as many books as I possibly can to cover the various areas of what goes into building a synth. I'm open to suggestion, but I'm sure there are quite a few threads on the subject. I really don't want to just slap one of these together, I would like to have some level of understanding of what it is I'm doing... From coding to soldering. So I'm going to hold of on building right away, and get some more knowledge and understanding first. I see some great achievements here, and I think there are more on the way. I would like to be able to help push the envelope someday, and make a contribution too. Thanks again for the help and advice everyone. -Stephen