Quoted from Alocatelli:

Thought I should throw in my experience as well if it helps anyone. I recently bought the most current edition of the rotten dog board that has the two blue adjustable pots for the sound built in. I also had purchased the new game and sound roms along with it from arcade shop. Without any adjustments it works absolutely great in my Williams Comet with both sounds balanced how they should be. The best part is the varying hum that was always present from the switched lights in the amplifier is non existent now. I couldn’t be happier with my purchase.