there are three knobs inside the coin door (that requires a key to open)
one controls treble, one controls bass, the third controls master volume (i believe it goes in that order, but i'm not completely sure, and they're labeled so it shouldn't be too difficult to figure out)
ddr machines are the same way, but they're probably labeled in japanese or korean, but even then, it's not exactly difficult to fuck around with it and figure it out |