JAMMA and Stereo question...

[fuzionmuse]

Need some help...

So I THINK I have a JAMMA wired conversion cab with an MV-1A inside... Not sure how to tell if it's only for the Neo-Geo (ie, missing the -5v thing) and also a question about stereo wiring and such...

1st, I looked at the harness, and there appeared to be a wire where that -5V wire should be, so I'm assuming it's a standard JAMMA cab?

Also, I only have 1 speaker (left) and was wondering how you'd go about adding another for stereo sound from the jamma harness... any advice?

I'm a n00b.

 

[norton9478]

The -5v wire won't hurt your setup....

Just leave it.....

MV1-A is not a stereo PCB... It's mono...

Modding for Stereo isn't worth your time.... Just get a stereo pcb.

 

[fuzionmuse]

If I do get a stereo pcb, how do I wire it into a system thats only got one speaker as is?

 

[andy251203]

Obviously get another speaker first. Then Rewire jamma pins 10 and L to go to each speaker individually as a speaker plus, and use a common ground for the two as a Speaker minus.

 

[fuzionmuse]

I'm missing something, is JAMMA mono inherently? I mean, is there no Left and Right Channel? I get the 10 and L, one is positive, one is negative, make a chain for the ground, and wire the positive separately... But no ACTUAL stereo? Right?

Edit: I think I just answered my own question...

 

[Hewitson]

JAMMA is mono, pin 10 is speaker positive and pin L is speaker negative.

The MVS pinout differs in that pin 10 is speaker right and pin L is speaker left. A common ground is used for the negatives.

 

[andy251203]

I thought he was specifically talking about getting a stereo MVS board. Other stereo jamma boards usually have a separate speaker connector for a right channel on the board with left channel mono on the harness.

 

[fuzionmuse]

OK, I get it now... Thanks for clarifying... I'm pretty sure my system was/is a regular jamma cab that was converted into a Neo-Geo... I'm going to add another speaker up top, but do I need extra voltage or would it be ok to just wire the thing into the existing architecture? Split the positive lead and chain the ground?

 

[Xian Xi]

OK, I get it now... Thanks for clarifying... I'm pretty sure my system was/is a regular jamma cab that was converted into a Neo-Geo... I'm going to add another speaker up top, but do I need extra voltage or would it be ok to just wire the thing into the existing architecture? Split the positive lead and chain the ground?

It'll be fine, not like it's a mega audio system. Although it might sound weird if it's a simulated stereo setup.

 

[not sonic]

sending the mono signal to two speakers is fine.

two 8ohm in parallel or two 4ohm in series would be "ideal" but i dont think itll make much of a difference either way.

just dont mix up + and - between the two if theyre in parallel, itll sound like poo poo.

similarly make sure you go + - + - in series.

http://www.termpro.com/articles/spkrz.html

 

[fuzionmuse]

Ya, I'll need to pull out the speaker that's in there and see what it is... I'll probably do it in series, but we'll see... that sounds easier...

 

[fuzionmuse]

EDIT: Double post.... Lame.

 

[Hewitson]

I really don't see the point of adding a second speaker if you're only going to have the sound in mono. I thought the whole point of this thread was stereo sound?

 

[fuzionmuse]

2 reasons.

1. I want the sound to be "even"... Like, an equal amount coming from the left and right side...

2. I eventually DO want stereo sound, and using quick connectors would be simple, so I see no harm in throwing another speaker in there in the meantime...

I'll probably have to buy another MVS board, probably a multi, because my MV-1A has no stereo and looks like it'll be a pain to mod...

 

[topher]

I'll probably have to buy another MVS board, probably a muti, because my MV-1A has no stereo and looks like it'll be a pain to mod...

You aren't going to mod that board to get stereo. Trust me, not going to happen.

 

[MKL]

You aren't going to mod that board to get stereo. Trust me, not going to happen.

Topher is right. The stereo you can get from a modded MV-1A cannot be used in a cab because the amplifier on that board is mono only. It would be different if it was a MV-1FZ which has an amplifier that can be configured for stereo so you could mod it to be the same as, say, a 2-slot.

 

[Hewitson]

I wouldn't say it can't be used in a cab, you'd just need to hook up an external amplifier.

 

[fuzionmuse]

Well, I'm NOT going to be moding this board, so I'll be putting in another speaker for future use and so that the only sound coming out isn't just on the left side, but centered...

 

[Neo Alec]

Such a pain that they didn't make a stereo option for most of the 1-slot MVS boards. What a waste.

Other stereo jamma boards usually have a separate speaker connector for a right channel on the board with left channel mono on the harness.

I've never seen a board like that. Usually the separate stereo connector handles left and right sound, not just one of the channels.

 

[Jae686]

Topher is right. The stereo you can get from a modded MV-1A cannot be used in a cab because the amplifier on that board is mono only. It would be different if it was a MV-1FZ which has an amplifier that can be configured for stereo so you could mod it to be the same as, say, a 2-slot.

So..... were can I find information about this MOD for the MV-1FZ?

 

[Hewitson]

Are you unable to use google?

http://www.neobitz.com/Pages/Mods/MV1FZ-S.aspx

 

[topher]

Are you unable to use google?

Seems the majority of people here can't.

No clue how they found this site.



Neo Alec is right.


I've always seen 4 pin connectors for stereo out or RCA out --> L & R channels.

Mono is mono. There is no left channel mono. Left channel mono would be stereo with only one speaker connected.

For anyone that needs to know, a standard floppy drive power cable works for all PCB stereo outs (except, obviously CPS which uses RCA out) and is usually pretty easy to find in thrift stores for about a US quarter or so.

 

[MKL]

Seems the majority of people here can't.

Well you're one of them and hewitson is another because the stereo mod I mentioned is for reconfiguring the stereo amp on the MV-1FZ to stereo and have amplified stereo from the edge connector like a multi-slot. And Jae686 apparently asked about *this mod* (he quoted my post), not the one on jeff kurtz' page.

@Jae686: I don't have the time to explain the details but basically you need to feed the L and R channels into the HA13001 amp, change the volume pot with a stereo one and reconfigure the HA13001 to stereo (the datasheet shows the different wiring, etc. between mono and stereo modes.

 

[Hewitson]

To be honest I didn't read the document I posted a link to, sorry.

 

[topher]

I didn't bother reading it either as I have no need for the information.

My comment was not speciffic to this thread but to a lot of common questions asked in general throughout the site.