Getting balanced audio on the AV Famicom without distortion

[2A03]

I seem to be having a whale of a time with the audio end of an AV Famicom that I'm modding for someone. I installed an NESRGB for him, and the audio amp included on it stopped working (!) after soldering a wire for expansion audio. I've tried experimenting with improving the pre-existing audio circuit (since expansion audio is too loud on the AV Fami) by swapping out the resistors on the audio pins of the 2A03 with lower values. While I get balanced audio on games with external audio, on regular games I get somewhat distorted audio. Does anyone have any suggestions as to how to get rid of the distortion? If not, I can try replicating the NESRGB's audio circuitry on a separate PCB, but I would like to be able to get this working before I resort to that.

This is particularly frustrating as I've pretty much finished installing the NESRGB for my customer, and this is literally the only thing preventing me from getting the system buttoned up and shipped out.

[80sFREAK]

Yes, i do, but since you are doing this for money, you are on your own. Same as anyone else.

[2A03]

Yes, i do, but since you are doing this for money, you are on your own. Same as anyone else.

Sooo what if someone else wants to fix this issue with their AV Fami and tries looking around here? It doesn't matter if I'm doing this for a commission, this is a known problem with the AV Famicom and there doesn't seem to be any definitive solution to this short of completely redoing the audio amp.

And you know, if someone else is having an issue with a mod, whether they're doing it for themselves or for a customer, I do whatever I can to lend them a hand. I don't get all weasely and say "oh I know the solution but you're on your own".

[80sFREAK]

[Pikkon]

I don't get all weasely and say "oh I know the solution but you're on your own".

Sounds more like a Drakon complex.

[fredJ]

With these kind of help, this forum-section is going to be useless.

[P]

I agree.

[famifan]

could you just send the link to this thread to your customer?

[Arkanix38]

Yes, i do, but since you are doing this for money, you are on your own. Same as anyone else.

I'm having trouble finding a concrete solution for this problem (modding my own AV Fami). I have an NESRGB installed if that helps w/ audio mixing and i'd love if you could PM me about this 80sFREAK. I've read other threads that suggest replacing the CPU Audio resistors and have also noticed the distortion after replacing them. I've read some of Drakon's old threads but find his posts/schematics rather difficult to decipher as they don't seem to be labelled well.

I love Lagrange Point and just got Akumajou Densetsu today and absolutely love the audio but can't stand Mega Man 2 and Recca sounding so tinny. Any help would be greatly appreciated!
Post Merge: August 16, 2016, 12:30:52 am
Never mind, went through the NESDev forums and found Tim's post on how to mix the expansion audio through the NESGRB