Loud sound makes distortions

[charles76]

Just bought an arcade, it works excellent but got one small issue that I’m looking to get help with… Whenever I crank up the volume the picture gets lightly distorted, the arcade monitor makes horizontal lines thats appears in sync with loud noises and pulses, mostly significant with bass sound. Turning down the sound makes them disappear. Any suggestions how to fix? It’s a generic arcade with Jamma and neo geo one slot.

[nem]

Grounding issue or interference perhaps?

Do you have continuity between all grounds (common ground, video ground, audio ground)? Personally, I follow the jamma spec and keep all three separate.

Are your speaker cables running beside the video wiring? You could try physically separating them.