Hypothetical audio mod board and audio questions

[spenoza]

OK folks, since you guys are the experts in this little corner of the forum, help me out with this crazy hypothetical, please.

One of my complaints about PCE/TG audio is that, despite good specs, sometimes the audio sounds a little rougher around the edges than I think it should. An unrelated complaint I have is that the PSG audio always seems mixed a little too loudly against the CD audio for CD titles.

As to the former, I was wondering what folks thought about a low-pass filter mod for PSG audio, with or without a higher-quality, cleaner amp circuit.

Also, has anyone toyed with the idea of adjusting down the PSG just a hair along the line that takes it to be mixed with the CD audio?