MVS sound problem

Hello, I got a question about my MVS 1 slot (Old one). When i bought my MVS mobo, I noticed something wrong with the audio (Stereo sound), but I didn't mind at the time. But now I've been playing The King of Fighters, and Metal Slug a lot lately, and It started to bother me. So, I want to know if it can be fixed?, and how can I fix it?. I relly dont know how to explain the sound problem, so I made a comparison video, from an MVS emulator, and my Egret II running the MVS game.

This is the emulator one:
http://www.youtube.com/watch?v=xGmQoAZ9w98

And this is the one from my Egret II:
http://www.youtube.com/watch?v=2wIlkjr-EJ0

I know for a fact that is not my cab, because I tested the same mobo with both my Egret IIs with the same results.

Thanks in advance for any help.

It -is- your cab. (Well... cabs)

This is exactly what happens when you plug an mvs into a standard jamma cab. It tries to output stereo onto mono wiring. In other words the stereo amp's both outputs go into the negative and positive terminals of the speakers, thus being forced to work against each other without a proper ground connection instead of both positive outputs going to separate speakers with a completely separate ground line. This is -bad- for your amp in the long run. It is like turning on your stereo, only to use both positive outputs of the left and right side to drive a single speaker. A decent stereo actually activates a protection circuit in such a case.

What you have to do if your cab has 2 speakers:

1. open your speaker compartment, both speakers should be wired in either series or parallel.
2. Run a single wire from the pcb connector ground up to your speaker compartment
3. Disconnect both speakers
4. at this point you should have 3 wires in your speaker compartment the 2 that were already installed and a new one.
5. connect new wire to the negative terminals of both speakers
6. connect the factory wires to the positive terminals.
7. do a sound check, you may need to reverse which positive wire goes to which speaker to get the left and right side correct.

http://www.jammaboards.com/store/neogeo-mvs-to-jamma-adapter/prod_198.html
or grab one of these ^

do note that they remap select to also function as button A as they assume you dont have a wired up select button on a vanilla jamma machine tho.

No point wiring directly to the speakers. The mvs->jamma adaptor is the easiest method.

I have a custom setup which doesn't require the adaptor, abcd,select working and proper stereo

Thanks for your reply guys, but I really don't think the problem are my cabs. The MVS that i got is this one:
http://www.hardmvs.com/html/MV-1.htm
As you can see, the harness type is Jamma, and it has a harness for stereo.
Anyone, any ideas?

You've flipped the switch to mono, right?

oh, ignore me you're using it in stereo.

Check the pinout on the motherboard matches that of the stereo connector you're using in the cab. One of the speakers might not be connected properly or something. You'll need the motherboard manual so you can check the schematic. I guess the E2 one would help too.

Connectors (check the E2 'F' and 'P' one)


E2 schematic (speaker pinouts are at the top right) (I guess its the same as the above but eh, can still be useful)
http://i7.photobucket.com/albums/y278/parple/ArcadeOtaku/Egret2Schematic.jpg

MV1 partial manual
http://hardmvs.com/manuals/MV-1 Partial.pdf

Check its connected with the correct pinout first, I guess.

Option 1:
One side of your amp is not working. Check your wiring, see if you're in mono or stereo on the board, check all connections are good and see if both your speakers work properly. Actually, put the game into test mode and do a sound test, you'll see what's going on.

Option 2: amps working against each other as in my first post, the telltale sign here is that sound effects and speech and the sort will not be even in volume. In most cases drums will be very loud whilst speech will be really quiet compared to that. Check your board wether the stereo=/mono switch is actually working.


Honestly I don't bother buying any adapters ever. Much cheaper to assemble one yourself.

Thanks again guys, I solved the problem a little with your help. So far, this is what happened.

I played a little with the Stereo/Mono switch and it kind of solved the problem:


Another thing is that the volume switch cannot go any further than this:

at that point everything sounds ok, but if I try to turn the volume up more than that, it sounds horrible.

and this is how it sound after i played with the Stero/mono switch and the volume switch:
http://www.youtube.com/watch?v=51ugw-MnydM

This is the sound test:
http://www.youtube.com/watch?v=s-h5oTojVXY

the right speaker sounds loud and clear, and the left one works but not as loud as the right one, the center (dont know what speaker that is) works fine, just like the right one. Again, I think is just the board that has problem with the Stereo/Mono switch, because it does exactly the same thing in both cabs, and other PCBs work just fine in them.

And finally, since I'm asking a whole lot of questions, and it will end up in a bad board (if it cant be fixed). Can I get one 4slot MVS (MVS harness) working in my Egret II if i get one of this?:
http://www.jammaboards.com/store/neogeo-mvs-to-jamma-adapter/prod_198.html

Again, thanks you guys for your time.

Yes, that adaptor will allow you to use a four slot. Also you'll need an extension harness as the E2's is pitifully short.

I know when you flip the E2's stereo switch to stereo it only disables pin 10 and not L, so you are possibly hearing double through the left speaker and not the right. Perhaps you could try disabling JAMMA audio completely, with a fingerboard straight through with those two not connected or something similar. Then using the stereo connector from the motherboard into the cabs connector might sort it out.

I had a similar problem, I use a four slot with a fully wired JAMMA extension, wired for 5 buttons. Plug it straight in but I also have an adaptor that has JAMMA audio disconnected, then I plug the E2 cabinets F connector into the headphone output on the 4 slot, this gives me balanced stereo audio with neither channel louder than the other. I remember when I didn't disable JAMMA audio, it was louder through the left side than the right.