Scart Cable L&R Sound hack help

Hi

Im currently underway to modify my NEO GEO AES unit and need some community help

Instead of cutting open a new hole in the case or using the "buffy" front audio output (which sucks if you ask me from the estetical perspective) i planed on using the "Video" pin of the A/V connector since pin C-Sync and Video are basicly bridged by a ferite bead on my board version 3-5 the pin could easy be cut lose by lifting the bead.

Problem is that im still not sure about a couple of things due to lack of datasheets for some of the chips and a function schematic of the AES.

So i have the following questions
is the "Audio Mono" on the A/V connector a mixed channel or a pure LEFT audio output ?

Are pins 9,10 Audio Left / Right on the YM3016 (red square)? if so can they be interfaced directly or do they haveto pass the 2 op amps (uPC4741C) before the signal is "loud" enought to be heard?

Do i need a Cap and a 10K pullup/pulldown to interface the output? (as on the endside of the Audio Mono)

Do i need to lift any components to make this happen or can i simply interface by parallel design? if so where might the best point be?

Yellow Square = Audio Filtercaps after YM3016
Blue Square = After 2'nd stage OP amp

Varning LARGE PIC

Are you trying to do this the easy way or hard way?

Well i would prefer to have it as simple as possible but, it wouldnt matter if it would involve some pcb contruction

MrKitt said:

Well i would prefer to have it as simple as possible but, it wouldnt matter if it would involve some pcb contruction

Click to expand...

The simplest way is to use the audio from the headphone jack. If you don't want to use that then you will need to build a small audio circuit to mix audio left, audio right and the analog as well.

shouldnt there be a point where i can tap the signals without building a muxer ?

and on a side note, the console loses sync randomly, any idea what might be the problem or is it possible that the game is malfunctioning ? only have one currently to test on :/

You can probably tap it from the 4741.

Actually you need to unmix:

http://www.neo-geo.com/forums/showt...o-to-3-6-AES&p=3233029&viewfull=1#post3233029

3-5 is the same as 3-6.

MKL said:

Actually you need to unmix:

http://www.neo-geo.com/forums/showt...o-to-3-6-AES&p=3233029&viewfull=1#post3233029

3-5 is the same as 3-6.

Click to expand...

reading the topic in the link, i have the same sound problem, on 2 of my mvs, so is the problem in the capacitors too?

on the mv-1fz- the problem started after i moded to 5v only + stereo sound
on the mv-4f - have the same problem too, i tested with a scart lead, and an 8 din (normal neogeo din), on the mv4f i have a lead to video, and another lead to stereo sound L + R, them both goes to a scart, then to tV, im using my normal neo cd lead.

the noise is a pain in the asss

Cant be sure but on my 2 6 slot unit the problem was bad caps once i replaced all caps the noice was gone.
Planning on doing the same on my MVS as i hear the buzzing sound all the time..

And all people Thanks for the help