MVS PCB to Jamma hack

massimiliano

massimiliano

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Hi, I'm in the middle of this problem:

I have an astrocity cabinet.
I've ordered a couple of MVS boards (a 2 slot and a 6 slot) but unfortunatly I won't be able to get an adapter MVS-2-Jamma soon.

So what do i need to do in order to avoid the sound chip compromise, but still do a check and possibly give the all-green to who sold me the boards?
Even a little trick like circuit a couple of wires to get mono sound could help me, once I verified I can wait until the jamma adaptor arrives.

Thanks a lot!
 
MKL

MKL

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The HA13001 amp you find on multislots can be configured for monaural operation. The mod requires about 7 steps and you need to change/move/add some resistors and caps. It's the only proper way of getting mono off a stereo MVS board. Personally I would never use one of those crappy adapters that don't do anything other than mixing the L and R channels together.
 
massimiliano

massimiliano

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Hi, thanks for the answers.

In case I was thinking about this adaptor:

http://www.jammaboards.com/store/index.php?act=viewProd&productId=198

Why is it crappy? :)

Anyway, what I would understand to manage my problem, is if i "cut" the wrong wire from the jamma connector of the cabinet (ie with a male-male board removing the relative trace) is possible at least verify if the board is fuctioning?

Even without sound i mean or redirecting it to an external amp, just to be sure it turns on, but without risk.


What you would do in my shoes? unfortunatly add/remove parts to the pcb is out of question as I need to verify if it's functioning as it is, so I can still send it back.

:)
 
MKL

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You can obviously disconnect the speakers as there will be one or more interconnects between jamma and speakers but all you need to do is turn the speaker volume adjuster on the board all the way down: the amp will have its inputs grounded and will just not work.
 
massimiliano

massimiliano

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MKL said:
You can obviously disconnect the speakers as there will be one or more interconnects between jamma and speakers but all you need to do is turn the speaker volume adjuster on the board all the way down: the amp will have its inputs grounded and will just not work.
Click to expand...

Good, it's what i was searching for! thanks MKL!
in this way I can connect the pcb and test graphic without harm it right?
one last question about sound:

Does the volume adjuster acts "globally" on the pcb, or i could test sound hooking a couple of speakers to another connector on the pcb like the speakers 4-pin connector?

Is there a non amplified sound connector so I can still check, with an external system ?

:)

Edit:

I must admit that I still don't know WHY the mvs is harmed when attached to std jamma...:confused:
 
MKL

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massimiliano said:
Does the volume adjuster acts "globally" on the pcb, or i could test sound hooking a couple of speakers to another connector on the pcb like the speakers 4-pin connector?
Click to expand...

There are two volume adjusters, one for the speakers and one for the headphones. You can test the headphones out but you won't know if the power amp/speakers out works or not.

massimiliano said:
Is there a non amplified sound connector so I can still check, with an external system ?
Click to expand...

The only non-amplified output is a mono one on jamma 11 but testing that will not tell you more than testing the headphones out and you still won't know if the stereo out on the edge connector works or not.

massimiliano said:
I must admit that I still don't know WHY the mvs is harmed when attached to std jamma...:confused:
Click to expand...

Because the jamma speaker will have a + where it expects a -.
 
Xian Xi

Xian Xi

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massimiliano said:
Hi, thanks for the answers.

In case I was thinking about this adaptor:

http://www.jammaboards.com/store/index.php?act=viewProd&productId=198

Why is it crappy? :)

Anyway, what I would understand to manage my problem, is if i "cut" the wrong wire from the jamma connector of the cabinet (ie with a male-male board removing the relative trace) is possible at least verify if the board is fuctioning?

Even without sound i mean or redirecting it to an external amp, just to be sure it turns on, but without risk.


What you would do in my shoes? unfortunatly add/remove parts to the pcb is out of question as I need to verify if it's functioning as it is, so I can still send it back.

:)
Click to expand...

Those adpaters work well from what I've heard. But honestly go with MKL's suggestion as it will hel you learn the ins and outs of your cab better. So in the future if something happens you know what to do.
 
massimiliano

massimiliano

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Xian Xi said:
Those adpaters work well from what I've heard. But honestly go with MKL's suggestion as it will hel you learn the ins and outs of your cab better. So in the future if something happens you know what to do.
Click to expand...


Yeah, on long distance I'll figure out the best solution.

For now the problem was just be sure the board i bought are functioning.
I couldn't send them back if I add/remove parts!

thanks a lot everybody
 
massimiliano

massimiliano

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hi I got news:


The boards arrived, but yesterday I just tried the 2 slot:

I lowered the speaker volume to zero, and then turned on the cab.
Everything was ok, (just couldn't try the games change, as didn't knew where the select button should be found ;) )

BUT surprise! when i tried to raise the speaker volume, it was clear and good!

Now, shouldn't the original board crack the sound? Maybe it was already modded?
 
massimiliano

massimiliano

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another question as you are all so kind:

I putted in the 2-slot mvs puzzlebobble (1) and Magicaldrop3 (2)

The attraction mode cycle only.. with puzzle bobble!

I then removed the pbobble cart from slot1, and powered on the cab: magical drop starts.

So Is there a dipswitch or option which will force attraction mode to a particular slot!?

:(
 
Neo Alec

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massimiliano said:
another question as you are all so kind:

I putted in the 2-slot mvs puzzlebobble (1) and Magicaldrop3 (2)

The attraction mode cycle only.. with puzzle bobble!

I then removed the pbobble cart from slot1, and powered on the cab: magical drop starts.

So Is there a dipswitch or option which will force attraction mode to a particular slot!?

:(
Click to expand...
Just pull them both out and clean them. It's always supposed to show both.
 
massimiliano

massimiliano

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Neo Alec said:
Just pull them both out and clean them. It's always supposed to show both.
Click to expand...


Hi, I've changed carts (gowcaizer and kotm2) and everything was ok.
I'll need to clean some cart probably!

Thanks for the hint, what do you think about the sound?

A non-modded multislot should crack the sound when attached to a jamma cab?
Is ther a way to understand it?!


Thanks!
 
Pas

Pas

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massimiliano said:
A non-modded multislot should crack the sound when attached to a jamma cab?
Is ther a way to understand it?!
Click to expand...

Not nessisaraly. It all depends on the cab...and the speakers in it. I have had some jamma cabs with high ohm low watt speakers that an mvs board would overdrive and cause a crackling effect...then I have tried in some with good quality high power speakers and didnt get a lick of distortion or crackle. It all depends on the speakers, wiring, etc. I wouldnt run it that way for long though becuase you can cause damage to the MVS board running it in mono (except the 1 slot boards which are supposed to be mono that is) and possably speakers if they are distorting badly...but I never had a problem from quick tests before I got a real MVS cab to work with.
 
massimiliano

massimiliano

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Pas said:
Not nessisaraly. It all depends on the cab...and the speakers in it. I have had some jamma cabs with high ohm low watt speakers that an mvs board would overdrive and cause a crackling effect...then I have tried in some with good quality high power speakers and didnt get a lick of distortion or crackle. It all depends on the speakers, wiring, etc. I wouldnt run it that way for long though becuase you can cause damage to the MVS board running it in mono (except the 1 slot boards which are supposed to be mono that is) and possably speakers if they are distorting badly...but I never had a problem from quick tests before I got a real MVS cab to work with.
Click to expand...

Great, it was the answer I was searching for. :)

I'll think something for the long distance !
 
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