Should I remove the diode then?Those need not.
oh right. I took that unifier off so I could take photos of all the pcbs, but I do put it back on before booting it.@ekorz your picture shows the Jamma edge unifier missing.
The RCA connector has no audio amplification. That's on the tiny edge connector.
There should be a 2-to-1 Jamma edge unifier that takes sound from the tiny edge into Jamma out.
You can see the sound routing here, appears to be on the 5th pin from the left. Pls. double check before blowing up the amp/speaker..![]()
I think those 2 examples came to mind for me. They are 2 systems I use on jamma that have at least some way to raise/lower volume from the line level RCA ports. I thought maybe the test mode would have an option. Maybe something is underpowered and it’s at max already...I don't have this board but AFAIK the pots are generally used to regulate the amplified audio which goes through the JAMMA edge.
Line level outputs never have pots because you're supposed to use them with an amplifier which will provide you a volume control. There are some notable exceptions such as Taito F3 where you have the possibility of lowering or increasing the volume via software in the test menu and CPS-2 which (again, AFAIK) do the same thing, but via hardware buttons. This can also be proven by looking at Capcom's Q-Sound amplifier which doesn't have a pot, because you're supposed to use it with the board's own volume control.
Ehh
https://drive.google.com/open?id=11Qu9W53UCVIiL_ULNXj9vIbQCyjoZQFHEhh
If the 12V stage is taped off, the amplifier on the qsound board will never amplify the sound for the jamma edge so there you go. (so what you posted earlier makes sense now). I've no idea why they tape off the 12V, maybe for testing and @lydz can explain better. I didn't know it was taped off. @suverman can you explain/show where _exactly_ there is tape so i can understand better?