hartke kickback humming and wore out

[weshead]

two questions:
1: i've had this hartke kickback 12 for a long time and it doesn't sound as good as it used to. any suggestions on what components to replace?
2: this amp has an XLR direct out, which is super cool, but whenever i hook it up to the mixer it makes the amp hum. it drives me nuts.

[weshead]

i got a little adventurous and took this amp apart, after some careful looking i found a lot of cracked solder welds. pretty much every one of them were for grounding pots and the input jack. after re-soldering them the hum totally went away.

i would still love any input on what components to replace to give it back its original punch.

-weshead