Modifying a NeoGeo MV-1B motherboard for Stereo and Mono out

[cools]

I want to get stereo (line level) output from my MV-1B, while maintaining the amplified mono-out. Will have to make it switchable, I guess, as I don't want the same hassle we get with CPS2 - output from the JAMMA edge at the same time as the phonos.

There's all sorts of guides on the web for stereo out on various MVS boards, including the MV-1B, but none seem to be for doing this...

http://wiki.cardboardbox.org.uk/doku.ph ... ogeostereo
http://www.neo-geo.com/forums/showthread.php?t=183497
http://www.neo-geo.com/forums/showthread.php?t=133519

Anyone have any ideas?

[mpoilu]

I've been researching all this lately too for putting together a supergun - there appears to be a way to just use a dpdt switch (instead of a 3 or 4 pole) and the circuit shown to take care of switching mono/stereo for Jamma/MVS. For the output level you could add a seperate external potentiometer to alter the output as needed when switching between amplified and (turned down) non-amplified?

http://www.neo-geo.com/forums/showthread.php?t=204537

[cools]

Really want to avoid using an attenuator if possible.

[thegreathopper]

Cools, If you look at post 9 on the Neo-geo link you provided MKL says if I read correctly mono and stereo will output at the same time with the mod Jeff Kurtz has posted post 8, I would tap off of the Op amp in the picture and go to a pair of phono sockets.

I have done a similar mod on a MV-1C and the stereo output is very high quality, My board now has a couple of phono sockets that plug in to a stereo amp.

[cools]

Cools, If you look at post 9 on the Neo-geo link you provided MKL says if I read correctly mono and stereo will output at the same time with the mod Jeff Kurtz has posted post 8, I would tap off of the Op amp in the picture and go to a pair of phono sockets.

I have done a similar mod on a MV-1C and the stereo output is very high quality, My board now has a couple of phono sockets that plug in to a stereo amp.

Then cut the traces and wire a switch in between the amped mono + JAMMA edge?

[thegreathopper]

Cools, If you look at post 9 on the Neo-geo link you provided MKL says if I read correctly mono and stereo will output at the same time with the mod Jeff Kurtz has posted post 8, I would tap off of the Op amp in the picture and go to a pair of phono sockets.

I have done a similar mod on a MV-1C and the stereo output is very high quality, My board now has a couple of phono sockets that plug in to a stereo amp.

Then cut the traces and wire a switch in between the amped mono + JAMMA edge?

Exactly that would work, but do you even need a switch? If you use the stereo out the speakers should be disconnected from the Jamma harness by default.

[cools]

Not in an E2

[thegreathopper]

Not in an E2

Never owned a E2 but does seem odd.

[cools]

Go check the wiring diagram

[Drakon]

http://www.hardmvs.com/html/PCBcompare.htm"

according to this the mv-1b only supports mono sound by default. kinda strange that other models of the mvs came outputting stereo sound but not this one