Dear BH community:
I have just finished building the crack amp (without Speedball upgrade), it passed all the resistance and voltage tests, and plugging my HD650 I immediately got beautiful sound out of it. But I have one concern: the power tube (larger one I assume?) gets pretty hot (I can feel the heat with my hand being 5mm above the tube) after running for 10 mins or so. Even the metal base plate becomes warm (not hot, approximately 45 C degree-ish). I installed the 4 feet for the amp. I want to ask if this temperature of the tube and base plate is normal? Thanks!