Woo-hoo, success! I was looking at the board again today and happened to notice the 2532/2732 solder jumper (to select a 2532 or 2732 EPROM) under #14 socket (mine has no #14 EPROM since it's not Crazy Kong part 2), and it looked different than the other 2 or 3 of those located on other sections of the board, so I assume it was set for a 2532, since the board uses 2732's and the rest of the EPROM's work. So I removed the solder bridge, and also remember seeing some regular CK board like that having the 2 sound EPROM's shifed one socket over (so #12 is empty, and #12 and #13 go in socket 13 and 14), so I moved #13 over to 14, with no sound, then moved #12 to 13 and lo and behold, I now have perfect sound!