For a quick fix: Buy or find in your toolbox a very narrow "jewelers" size flat screwdriver that fits within metal part of the control. Use a lighter or torch to heat it up until it can melt the plastic. Using a little pressure melt a slot into the plastic post to about 1/8" (3.5mm) deep. Let it cool. You can now use the screwdriver and the slot you created to adjust the volume.

Secondly, if you want to replace the pot yourself, I would call Axiom and ask for the values on the pot. For example, is it a 500kilo-Ohm or 1 mega-Ohm etc. I would imagine being a volume pot it would be music taper, not linear taper. I would not suggest this unless you are comfortable working around high current electronics. My guess is that there are some pretty high-value capacitors and such in the amp that could ruin your whole day plus the rest of your life if you don't know what you are doing. Any amp repair shop could do it for you at probably a reasonable price (probably the base time rate, .5 hours or an hour).

But please don't let UPS get off too easy. Give 'em some hell the best you can. Don't want them to get more complacent than they already are.

"That's some catch, that Catch-22." "It's the best there is." M22ti VP150 EP350 QS8 M3Ti