Strange GND? Noises with Jammaloom in NNC

[RoZioN]

So I bought a Jammaloom from RS to play some classics on the NNC with a ToshPF.
Newer boards sounds fine but I get weird static/gnd noises (even if the volume is 0 the speakers still make the sound) when using older boards.

Can this be due to the lack of -5 in the cab? If a board required that then there shoukdn't be any sound at all?

Here I have a video showing the problem, this is with the volume off, but I still get the sound when the helikopter comes.

Big thanks for any input

https://www.youtube.com/watch?v=2HGN7hrZC1Y

[Cageman]

You could check if the video ground is properly connected with these boards. Check JAMMA pin 14, should be 0 Ohms to ground.

[RoZioN]

it needed a high to low converter =) But thanks for your input!

[battlesmurf]

it needed a high to low converter =) But thanks for your input!

A high to low converter? Having the same issue.

Thanks!

[RoZioN]

Yes, it sorted it. I dont how how I can explain it more clearly, you need to take the already amplified signal, and bring that down so that the internal amplifier can do its job =)

[battlesmurf]

Yes, it sorted it. I dont how how I can explain it more clearly, you need to take the already amplified signal, and bring that down so that the internal amplifier can do its job =)

Did you have reccomendations on what type of H/Low? I see that amazon has a bunch. Did you hack any wires? Etc.

Thanks!

[RoZioN]

I bought one locally in Sweden. it has wires for +/- for R/L . So I just took apart an old RCA->scart adapter and harvested the RCAplug from that.