Lower Noise on VGA Output via JAMMA Adapter

[banane]

Hi all,

does anyone how to address noise on the VIDEO lines ? I already have fixed all the ground loops on my arcade machine,
but when I use Antonio Villenas Jamma Adapter my picture looks like this:

1.jpg (2.31 MiB) Viewed 1457 times

My Monitor I test with is a Hantarex Polostar 25 with both regular Hantarex RGBHV-Input-Socket wired to Jamma and VGA input.

I tried to directly wire the MiSter VGA output to jamma:

4.jpg (376.76 KiB) Viewed 1457 times

This removes a lot from the noise but still there little artefacts present:

5.jpg (634.68 KiB) Viewed 1457 times

When I directly use a shielded VGA cable from the MiSter to the VGA-Input of the Hantarex Polostar 25 all the noise is gone, which tells me this is still a shielding / GND problem.

Can anyone give a hint how to adress this on the Jamma-Adapter ?


Thanks and kind Regards
Banane

[banane]

As a workaround I could also use the shielded VGA cable, but as soon as I disconnect the VGA cable from Antonios Jamma Adapter, I lose sound and controls.

What do I miss ?

[lateski]

Hey there! Did you manage to solve this issue with direct use of Antonio's JAMMA adapter?

I have the same background noise when running this set up on my arcade machine. Running any of my standard JAMMA PCB boards is absolutely fine (on a Nanao MS9 chassis) - and running the mister on a consumer CRT (with Antonio's composite adapter) is fine as well.

I suspect the combination of the JAMMA adapter and my system just don't gel? Everything else fires up and sync's fine - just that frustrating background noise.....

Hope you got it sussed!