The audio passes through one of the gates of the 74xx368 chips, most likely for buffering.
Thanks I'll try to replace it in my famiclone!
@80sFreak - my famiclone doesn't have a microphone... actually I have never seen a famiclone with a microphone here in Europe.
How about wiring? If PCB layout is the same, you have unshielded wire, connected to sound amplifier (xx368). A bit hard to help without any photos or audios.