Neo Geo Audio Wiring Question

Evewalker

Active member
Joined
Sep 11, 2009
Messages
666
Reaction score
25
Location
Pawtucket, Rhode Island
I have a small question question regarding audio rigging on a Neo Geo conversion. Any insight would be greatly appreciated.

This past weekend, I picked up a 2 slot conversion in rough shape for virtually nothing. It looks like somebody had dropped the guts of a MVS into an Atari Blasteroids cab. Everything appeared to be functional, except for the sound.

Anyway, after a great deal of cleaning and external repair, I started to tackle the wiring. My knowledge of cabs is limited (yet increasing), but it was pretty damn obvious why there was no sound. Turns out that the audio wires were disconnected and caked with solder. I cleaned the solder off, and took some photos, which are below.

Now, I know that for any stereo set up you need both L and R wires connected to the speakers, along with an extra ground. The strange part is that I can't seem to find a spare ground to run, and on top of that, the two speakers seem to have four separate wires connected via quick connects (two white, two colored) leading down into the cab. This is completely different from my other dedicated MVS systems.

What should I do to get this thing correctly wired for audio? I have a feeling that there is something simple I'm missing. I tested the audio through headphones via the jack, and it was crystal clear.

In addition, just to complicate things a bit, there is a third speaker in the cab, mounted on the front. This is also disconnected. Is there any practical way to make use of this additional speaker in a stereo setup, or should I just ignore it?

Here are a couple of photos to better show what I'm talking about:

http://www.thetemplegames.com/pub/audiowiring1.jpg
http://www.thetemplegames.com/pub/audiowiring2.jpg

Thanks everyone.
 
Trace the speaker wires from the Jamma harness and see where those go. Make sure they lead to the speakers and if they don't then see where they are going. You will also need to turn up the volume by sliding the tab labeled speakers to the left towards the memory card slot.

If this doesn't produce sound then chances are the sound section caps on the board might be bad. Channelmaniac repairs these and also sells cap kits if you can do the repair yourself.
 
A couple of things

If you're using the standard JAMMA wiring, JAMMA is not stereo. If this is hooked up to the headphone jack wiring or NEO GEO MVS type wiring it will be stereo.

I would start by downloading the MVS manual for the board you have and verifying what this model has.

My guess is the extra wires are from trying to add extra speakers or a sub to the stereo wiring.

Check out this site: http://www.hardmvs.com/

It has a lot of good info of Neo Geo stuff.
 
If it is wired for mono, you should get some type of sound through the speakers... Doesn't sound good... but it's there.

As for the 4 terminals... Some speakers have two terminals for each pole. They are usually for daisy chaining and stuff... Use a multimeter to see which ones are paired up.

You can find that ground from just about anywhere... Just tap one in.
 
Back
Top Bottom