Neo Geo MV2F on Egret 2

[vibribbon]

Hiya,

Anyone running a 2/ 4/ 6 slot neo geo mvs on an Egret 2 by chance?

I bought a MV2F recently. I already have a MV1C but I wanted the 2 slot so I could use the memory card function.

I plugged it in and it exhibited some weird sound problems.

Looking on the internet and this Luke Morse video came up showing exactly the same problem and the easy fix by moving pin M (audio ground) to a ground pin.



So I knocked up a quick adapter that does this but nothing changed. Upon closer inspection, I noticed that pin M on the Egret 2 jamma connector isn't even wired!

Am I overlooking something obvious?

Any help appreciated. Cheers!

[yosai]

[vibribbon]

Hi Yosai,

The solution offered by Luke is to ground pin M (audio ground). On the jamma connector of the Egret 2, that pin is not even populated. What would you suggest? Make sure all the ground pin on the MVS side are connected to each other? As it is, pins 10, 11 and L are just connected to their respective pins on the adapter (passes through).

[yosai]

Try disconnecting L & 10 so that they don't pass through.

[Yams]

Upon closer inspection, I noticed that pin M on the Egret 2 jamma connector isn't even wired!

Am I overlooking something obvious?

Any help appreciated. Cheers!

(Removed - I was wrong)

[leonardoliveira]

Do not connect the edge pins of the JAMMA connector to GND EVER. You will fry the amplifier on the board. Some arcade boards are mono but do use the two wires floating using a special boost configuration called "BTL" (Bridged Tied Load) where one channel amplifies the positive half of the signal and other channel amplifies the negative half.

MV2 and MV2F are not JAMMA boards. What make them not be JAMMA is that they require special speakers wiring.

L is connected to LEFT speaker plus terminal and the minus terminal is connected to the cab GND rail.
10 is connected to RIGHT speaker plus terminal and the minus terminal is connected to the cab GND rail.

If you tie L to GND you will blow one side of the amplifier.

Because L and 10 are operating different than what JAMMA expects, what you hear is the difference between the channels. You will only hear anything when a game do a stereo sound effect if there is only one speaker connected to L and 10 following the standard JAMMA wiring.

PLEASE DO NOT FOLLOW the advice of connecting L to GND.

[vibribbon]

PLEASE DO NOT FOLLOW the advice of connecting L to GND.

thanks for the detailed explanation. i have not attempted to make any further trials, so i haven't connected L to GND (thank goodness!).

that is why i'm hoping to find someone who has the exact setup and have hopefully the solution to this problem.

maybe i need to go via the P Plug route on the Egret 2 and make use of stereo?

surely i'm not the first person to encounter this problem?

[bloodhokuto]

I just use an adapter.

One of these:

https://www.videogamex.com/neo-geo-mvs- ... ne-adapter

[leonardoliveira]

That adapter makes it mono, no? That would be a shame, Neo Geo has such a great sound when in Stereo... lol

[leonardoliveira]

Just to clarify, when I said not to connect the L pin to GND I meant the pin that goes to the mainboard at the JAMMA connector should not be connected directly to the GND, not the wire that is coming for the mainboard from the speaker. The instructions were very vague, even if the person did not meant to give that particularly (bad) advice.

Someone could have the lazy idea of straight up tying a jumper wire from L to GND and leaving it connected to the mainboard side of the wiring. It happens very often, actually.

[penrhos]

That adapter routes mono to the jamma edge connector and stereo to the 4-pin connector.

Also has connector for cart-select on button 5.

I used one to test the multi-slots I just sold...

[Yams]

PLEASE DO NOT FOLLOW the advice of connecting L to GND.

Oh wow. ****, sorry about that. Guess the advice I was given was bad. I'll edit and delete that. Good explination.

[vibribbon]

I just use an adapter.

One of these:

https://www.videogamex.com/neo-geo-mvs- ... ne-adapter

hi, can you confirm you are using this on an egret 2 with either a 2/4/6 slot? cheers.

[penrhos]

I can loan you mine or give me a few days I can make a mono adapter and swap service & test over too.

[vibribbon]

I can loan you mine or give me a few days I can make a mono adapter and swap service & test over too.

that'd be great. or alternatively, if you can figure out how the machined adapter is wired for sound, just lemme know and i can amend mine? i dont mind playing in mono at all.

[penrhos]

I've got the parts needed - I'll try to knock one up over the next couple of nights. What pin is your "test" button connected to and is fire-5 connected to anything?

[vibribbon]

I've got the parts needed - I'll try to knock one up over the next couple of nights. What pin is your "test" button connected to and is fire-5 connected to anything?

My TEST button going from Jamma (15) > MVS (M) does work, it puts the system into the menus.

SERVICE adds a credit

I've put wires to my MVS (d) and (26) with the intention of putting a switch there, but not tried yet.

cheers.

[bloodhokuto]

I just use an adapter.

One of these:

https://www.videogamex.com/neo-geo-mvs- ... ne-adapter

hi, can you confirm you are using this on an egret 2 with either a 2/4/6 slot? cheers.

Using a 4 slot on an E2, works fine.

[penrhos]

Hasn't the E2 got a mono / stereo plug on the audio leads or an I imagining things?

[bloodhokuto]

Actually I never looked into the stereo thing till now, as my E2 does not have the amplifier that allows stereo through phono. I assumed (wrongly) that there was no Stereo on a stock E2.

But it seems that the stock has stereo through a JST 4pin plug. This was intended for the TAITO F3 setup.

I also notice the MVS-JAMMA adapter has a 4 pin stereo audio connection. I suspect that I could plug these together for true stereo MVS on the E2.

Unfortunately I can't test this at the moment, maybe another E2 owner can clarify?