I picked up my first duo recently. The audio from the system was messed up (buzzing, clipping). I replaced four 10 uf caps and the buzzing went away completely. The system when I first turn it on has no audio. 7-10 seconds later I get clipped audio that slowly normalizes. After another 10 seconds the audio sounds perfectly normal. I'm assuming I need to just replace more caps. I also did the s-video mod and it looks just as fantastic as the s-video from my white pc engine.
Anyway I was playing my duo and noticed that the cd audio sounds identical to my briefcase unit, but the non-cd audio is more muffled than my briefcase system. My question is, are duos just more muffled with non-cd audio or do I need to replace more caps?
I'm interested in this topic as well. The chip music from my briefcase setup/white PCE/SGX is also much clearer than that of my Duo-R.
It's hard to explain, the volume is fine on my Duo-R but the chip audio seems slightly muffled, sometimes I swear I can hear a barely audible and very high frequency squeal too.
You really need to replace all the caps on a original Duo. It would be ideal.
Even when replacing all the caps I do notice that the ADPCM audio is a bit crisper on a briefcase than a DUO. However, the Hu card chip audio and CD music should be almost the same.