Thanks for the info. I had no idea that a loose contact on the tube pins could shorten it's life like that. I've only used the unit for 250ish hours total so far, and the previous owner said he used it for 10. It's possible he used it more than 10, but probably not that much more. How long do these tubes usually last?
Hopefully my tubes aren't going out already, but I guess if they are, it's never too soon to start my tube rolling journey.
How do you guys feel about buying tubes from ebay?
I'm still unsure where the hum is coming from...I can't really hear it on my grados and akgs, but with the etys I can even hear it pretty clearly when the volume is at the 7 o'clock position (all the way down)! I notice that when the power cord of the amp gets close to the interconnects it gets louder. I wonder if I upgraded the power cord, interconnects, and added balanced power it would completely disappear? Not that I can afford to do such a thing at the moment.. I'm going to upgrade my interconnects soon anyway, so hopefully that'll help a little with the hum.