I've set up global variables for the voume of sound channels 1,2 and 3
for example; channel 1 is for music tracks, 2 is for sound effects. So they can be adjusted in the options menu.
When I try to adjust volume of a single sample in channel 1, it doesn't change, if I have that same sample in a channel that's not effected by a global variable it adjusts fine.

Shouldn't I be able to adjust a specific sample even if it's in a channel that's effected by something else?

Also, how many channels is it safe to use. Would some sound cards be limited to the number of channels (or samples) used at once?