Hey guys, wondering if you can help me pinpoint a problem I'm having with my amp. It's a Fender Blues Deluxe RI. I've noticed that playing around an hour, the volume drops a bit; recently it's been happening on a shorter time. Not only does the volume drop a bit, but there's a hum present when I'm plugged in, which is my main concern/problem. If I unplug the cable, the hum is reduced to almost nothing/normal, but still present. With some pedals connected inbetween and engaged (especially distortion pedals) the hum is louder. I also lose some highs and the amp behaves and responds differently when this occurs. I've placed a fresh set of power and preamp tubes with proper bias, and other than the speaker, the amp has no mods at all. I've been trying to do some research and I'm starting to suspect that the power transformer may be wimping out, as it does get pretty hot when this problem starts to happen. Could this be it? Any suggestions?