they were not necessary but i had those spare heatsinc and i used to try if the temps would had gone down. by the way i'd like to try also the mkl stereo mod, do you know anyone who can sell me a preassembled smd version?Would have to be a first for me to see heatsinks on the GRC and YM2610. I mean I know the YM2610 can get warm and I suppose the GRC could also...but is that really necessary?
About the smd revision i am searching for a prebuild one because if i would buy parts it will cost me more shippings than a premade one with all components already soldered. I desoldered everything and removed the 5v mod but the problem still persists. neogeo bios opening sound is good but others sounds aren't good.It's SMD but I remember a THT rework on oshpark somewhere: https://oshpark.com/shared_projects/q6nKRQBW
Was that the thread about flattening the MV1B? Thought I sold that board to Finch. Anyway the soldering for audio looks pretty shoddy and you should tap better spots on the board, especially the one you have glued to the connector.