Sega Blast City no JAMMA sound buzzing fix

[Chron]

I was having issues with mono Jamma no sound/buzzing but if i hooked up sound via the RCA connectors i had no issues. Obviously i also wanted mono sound to work for my jamma pcb's.

@Hatsune Mike made a thread about his issues last year and it really helped me out. Orginal thread Sega Model 3 (Blast, NVS4000, etc) no JAMMA sound / buzzing fix

I replaced vertical R1 resistor on my amp (10 Ohm) and my issues went away. When I pulled the old resistor i thought it checked good but replaced anyways and it definitely solved my problems.

Thanks and good luck to whoever needs this post in the future.

 

[Ziggy Cheetos Dust]

I needed this post thanks. I had speaker buzz after plugging in my Mistercade RCA while it was on. The mono was unplugged but it was still enough to make that “amp” noise and cook the resistor. I swapped out mine out with a 1/2 watt version that was also blue like the original.