Is it possible to use a CMVS in a cab?

[aha2940]

12v powers the sound amp though.

You are correct Gohan, however my MV2F still works and sounds fine when fed with only 5V, no idea how or why. I used Xian Xi's document to mod it, I think he can let us know why it works that way.

 

[Atro]

I would avoid the 5V only mod - there is absolutely no added value in hacking up your board given that arcade PSU's and laptop style PSU giving both 5V and 12V are readily available. The other advantage of keeping 12V is you can use it to get the proper AV input selection / 4:3 ratio switching on a scart TV upon powering up the CMVS, which comes in very handy.

Nothing else to add here.

/thread

 

[Xian Xi]

You are correct Gohan, however my MV2F still works and sounds fine when fed with only 5V, no idea how or why. I used Xian Xi's document to mod it, I think he can let us know why it works that way.

On a 2F, the sound system requires 5v to power the opamps which is generated from the 12v line going through a 7805 to convert it to 5v. With the 5v mod, you are simply bypassing the 7805 and directly supplying the opamps with 5v. This generates sound but without 12v the sound amp will not work but the headphones will still output audio. This is why it can still be used in a cab. Once in a cab the 12v line will power the sound amp producing sound from the edge connector.