That's just the way these boards are it seems. I got one for my F-14 and while the music is ok, the actual voices and sound effects are much louder than the music and sound terrible compared to the default sound board. Luckily I have it as a spare now as I got the original board fixed but the stock one sounds much better with actual bass and voices that won't blow your ears off if you turn up the game, the new board just sounds so lifeless in comparison.

Good luck woodmedic, if you can get a working MPU or fix the current one that is much preferred. If I did it over again I would have fixed mine and saved the $500+ dollars to get the Rottendog shipped here and with currency conversion, although at least if something happens it will be a suitable replacement, just with crappier sound.

In regards to the video, that loud buzzing when the game is flipped on doesn't seem to be normal, my Rottendog board is definitely not doing that as an FYI.