SNK VS CAPCOM CHAOS PCB Sound Explaination.

chris1

POCKETBIKE NUT,
Joined
Oct 18, 2002
Posts
10,830
I did a few searches here and came up with some info but I can't find and explanation for..my SNK VS CAPCOM CHAOS PCB Sound question.
I popped in the PCB in my 4 Slot big red that is wired up Stereo and I get DUAL Mono sound..Not Stereo.

Both speakers are playing but it's Mono in both speakers..
(Man it's loud with the volume turned up)

What I'd like to know is how this occurs when in the Manual/Main Harness section it says Speaker(-) L.....10 Speaker (+)..
An Explanation...
If I'm missing something here or I'm talking crazy please let me know..:tickled: :loco:


If someone can explain this to me I'd appreciate it..

Main Harness Page Scanned from the manual..
SVCMAINHARNESS.jpg
 

ttooddddyy

PNG FTW,
Joined
Nov 29, 2001
Posts
8,335
Looking at the harness wiring, the board is mono. Where does it mention stereo?

The way its hooked up in your mvs cab will give an output from both speakers but may be distorted in theory. Jamma board outputs do not usually have the speaker negative grounded, some do but not this board (I think) the audio output stage has two outputs, + and - running in a bootstrapped configuration.
So running from L to ground and 10 to ground will give an output from each speaker.
Maybe its designed to run OK in mvs (but 2X mono) and straight mono jamma cabs as well.

The test switch is also wired as with straight jamma.
 

chris1

POCKETBIKE NUT,
Joined
Oct 18, 2002
Posts
10,830
ttooddddyy said:
Looking at the harness wiring, the board is mono. Where does it mention stereo?

The way its hooked up in your mvs cab will give an output from both speakers but may be distorted in theory. Jamma board outputs do not usually have the speaker negative grounded, some do but not this board (I think) the audio output stage has two outputs, + and - running in a bootstrapped configuration.
So running from L to ground and 10 to ground will give an output from each speaker.
Maybe its designed to run OK in mvs (but 2X mono) and straight mono jamma cabs as well.

The test switch is also wired as with straight jamma.

I think I read somewhere in an old thread..someone thought it was stereo..
But,
I guess I was asking more of a question then saying it's not Stereo..
I figured they would make this in Stereo..

I was a bit reluctant to plug it in after looking at the harness wiring since my Big Red is wired for Stereo.

Searching old threads I see people were just plugging them in..
When I plugged this into the MVS and both speakers worked I was very surprised ..

I have to admit having this PCB in a "4 slot" MVS cab sort of sucks since I'm so used to switching games..in that cab..

It plays sweet though.and looks great on screen..

I was thinking about putting this in the Tekken 3 cab since that's a one game machine,to free up the big red or Candy and still be able to play it when I want..easily.

I'm not sure if I can do that....(?)


Thanks ttooddddyy..
 

lill-c

Dodgeball Yakuza
Joined
Oct 22, 2003
Posts
625
If you want to run both speakes in you're red cab for SVC you should run them in series leave the + wire on the right speaker move the - to the - on the left speaker and put a wire from the - of the right to the + one the left to have 2 speaker mono.

You can put that board in the Tekken cab, you mite run new wires for the buttons and just unhook the one for what ever board is in there or if they are the same but diffrent location just switch wires around on the buttons like I do if I have the CPS2 board running in the conversion cab.

DSC00883.jpg



DSC00882.jpg


DSC00881.jpg


For the MK2 board I hoked up the low punch low kick buttons into the kick harness for the CPS2

WIRES ARE GOING TO GET CLEAND UP THIS WEEKEND. TO MUCH TESTING OF THE NEW PCB BOARDS THIS WEEK!!!!!
 
Last edited:

chris1

POCKETBIKE NUT,
Joined
Oct 18, 2002
Posts
10,830
lill-c said:
If you want to run both speakes in you're red cab for SVC you should run them in series leave the + wire on the right speaker move the - to the - on the left speaker and put a wire from the - of the right to the + one the left to have 2 speaker mono.

You can put that board in the Tekken cab, you mite run new wires for the buttons and just unhook the one for what ever board is in there or if they are the same but diffrent location just switch wires around on the buttons like I do if I have the CPS2 board running in the conversion cab.

DSC00883.jpg



DSC00882.jpg


DSC00881.jpg


For the MK2 board I hoked up the low punch low kick buttons into the kick harness for the CPS2

WIRES ARE GOING TO GET CLEAND UP THIS WEEKEND. TO MUCH TESTING OF THE NEW PCB BOARDS THIS WEEK!!!!!

Cool..

Wow!! my friend you've been busy..I didn't know you had all that set-up already..
 

MKL

Basara's Blade Keeper
Joined
Mar 8, 2002
Posts
3,685
chris1 said:
I popped in the PCB in my 4 Slot big red that is wired up Stereo and I get DUAL Mono sound..Not Stereo.

Both speakers are playing but it's Mono in both speakers..

If the cab is wired for stereo, both 10 and L go to the positive pins of the speakers. Now if you plug a mono board (like SVC) into the same setup, 10 is still a positive but L is now a negative which means one of the speakers has both pins going to ground: how the hell can sound come out of a speaker wired like that? It just can't...
 

Stu

Overtop Pathfinder
Joined
May 23, 2003
Posts
104
Re: Re: SNK VS CAPCOM CHAOS PCB Sound Explaination.

MKL said:
If the cab is wired for stereo, both 10 and L go to the positive pins of the speakers. Now if you plug a mono board (like SVC) into the same setup, 10 is still a positive but L is now a negative which means one of the speakers has both pins going to ground: how the hell can sound come out of a speaker wired like that? It just can't...

Normally the MVS stereo audio signal would travel like this:

10 > (+)Right Speaker(-) > ground
L > (+)Left Speaker(-) > ground

But with a mono board plugged in the same setup, the ground wire (jamma pin e, f, 27, or 28) acts as a bridge between the 2 negative pins of the speakers. So the speakers would function like they're wired in series, but with the left speaker's polarity reversed. The audio signal would now travel like this:

10 > (+)Right Speaker(-) > ground > (-)Left Speaker(+) > L
 
Top