Neo Geo MVS cab with a 1 slot Jamma

gamelife00

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Hello, I recently bought an MVS cab which originally came with a multi slot board but was changed for a 1 slot MV1F at some point. It seems to be working fine but from what I've read Jamma can't work on MVS cabs and vice versa, I'm guessing that it must now be Jamma wired for the 1 slot to be functional? Thanks in advance
 

Xian Xi

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It's the sound that will be the problem. MVS is wired with speakers in series and JAMMA in parallel.
 

gamelife00

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The music sounds ok to me so does this mean it's prob wired for jamma and is fine? I'm not very knowledgeable about this side of things. I also noticed that 'game select' button is now my 'coin' button and the test/service switches inside my cab don't work
 
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gamelife00

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It's the sound that will be the problem. MVS is wired with speakers in series and JAMMA in parallel.

Also my MV1F has a mono/stereo switch, if the cab is MVS wired would moving to stereo fix any potential problems with sound long term?
 
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gamelife00

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So I've had a look at the wiring in my cab but I can't tell.if it's in series or parallel...so each speaker is 8ohm, the left speaker (left connector) is wired to PIN L , right speaker (left connector) is wired to PIN 10. And then it looks like there's a wire running between each speaker connected to both right connectors of each speaker. There's a cable going from PIN 11 (mono) but can't find what that's connected to,hoping you can tell from this how my set up is? Many thanks
 
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shadowkn55

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Flip the switch on your MV-1F to stereo and you'll be fine. It'll work on your cab except for the test switch. If you have a unibios, you can access the test menu through that.
 

gamelife00

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Flip the switch on your MV-1F to stereo and you'll be fine. It'll work on your cab except for the test switch. If you have a unibios, you can access the test menu through that.

I did try that but in the MVS sound test the left/right was coming out of both speakers at the same time. I still think that this wiring in series/parallel is what makes it correct it not.
 

Xian Xi

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I did try that but in the MVS sound test the left/right was coming out of both speakers at the same time. I still think that this wiring in series/parallel is what makes it correct it not.

I'd check the speaker wiring to see if it's wired in series or parallel. If it's in series, left speaker - will be connected to right speaker -, not ground. Use a multimeter to test the wire thats there now to see if it's ground, if it is then it's most likely wired as dual mono which is why there's no separation.
 

gamelife00

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I'd check the speaker wiring to see if it's wired in series or parallel. If it's in series, left speaker - will be connected to right speaker -, not ground. Use a multimeter to test the wire thats there now to see if it's ground, if it is then it's most likely wired as dual mono which is why there's no separation.

Hi, thanks for getting back to me :). There is a wire going from left - to right - . I've got a multimeter but how do I check if the wire is ground on not, where do I connect the meter and what reading should I be looking for (also, what do I set in the meter itself, DC voltage same as checking the +5 line)? Many thanks. Will this check determine if it's in series or parallel or just if it's dual mono?
 
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gamelife00

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Also, even though I've not checked using a multimeter Ive double checked the wires. There is a wire running from ground player 1 start button into the - pole of left speaker, and then a wire from - pole of left over to - pole of right speaker. So if this is the case is it wired for duel mono and are 1 slot MVS Jamma boards safe in this MVS cab? Thanks...what's also confusing me is that the seems to be a seperate ground wire attached to a screw of each speaker ( at the base where it screws into the cab)
 
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Xian Xi

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Yup, dual mono. You can simply disconnect that wire from ground and just connect the two speaker - poles together to convert the speakers to MVS stereo. So it sounds like the cab was converted to JAMMA, try testing all the other functions like Test button with the 1 slot. If the test button works (brings up the test menu) then it sounds like it was fully converted. From there you can decide to keep it as JAMMA or rewire it back to MVS pinout. But keep in mind that if you rewire it back to MVS pinout that you will need a JAMMA to MVS board adapter to use that 1 slot in the MVS cab or get a multislot motherboard.
 

gamelife00

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Brilliant. So just to confirm. If I leave as it is now my 1 slot will be fine,and if i disconnect the ground to - left (leaving the wire going from - L to - R that will put the speakers 'in series' MVS stereo). So with it as it is currently, it's neither in series or parallel, and how is any signal then getting to - L if it isn't physically wired to anything ( if that makes sense) PS, the test button doesn't seem to work so guessing that was just left as is. Appreciate all the help!
 
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Xian Xi

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Correct. Speaker - on JAMMA is usually just ground.
 

gamelife00

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Thank you :) , I don't realise switching audio from MVS to Jamma was that simple (just disconnecting a ground wire)
 

gamelife00

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Hi, thanks for getting back to me :). There is a wire going from left - to right - . I've got a multimeter but how do I check if the wire is ground on not, where do I connect the meter and what reading should I be looking for (also, what do I set in the meter itself, DC voltage same as checking the +5 line)? Many thanks. Will this check determine if it's in series or parallel or just if it's dual mono?

Could you also let me know how to check using a multimeter :) just for future reference. Many thanks
 
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