Hey UG!

My new Peavy Valveking just came in and it sounds(ed) awesome! I was playing with it for a couple of hours before I decided to go get some food. When I get back I power it up, let it warm up, and start playing. Only this time, i had a really loud hum that wasn't there before. :/ I shut it off and I hear some popping, I assume thats just the tubes cooling off? I'm just wondering why there is this loud hum. I'm playing it just below the Volume of 1.

What type of guitar are you using? It could be your pickups picking up the magnets running in your computer monitor making the humming noise (happens to me all the time and I turn off my monitor when I record.)
I'm using a Gibson SG Faded, stock pickups (490R/490T I believe). Could it just be some random electrical interference? I don't think I had the light on last time I played, but I know the computer monitor was on. I'll try shutting both off though, and I'll let you know.

Thanks for the quick response!
Update: It seems to be the power chord that came with the amp is messed up somehow. I used a different one that i had for an extra computer and now it works flawlessly. Thanks for your aid ShizNick.
The power chord that came with your new amp was messed up? How was it messed up do you know? I'm just curious now.. ha
Quote by ShizNick
The power chord that came with your new amp was messed up? How was it messed up do you know? I'm just curious now.. ha

I don't know how. I just figured this out because when I first plugged my amp in, I used this spare one that came with my other computer. (I did't see the cord that was in the bottom of the box :P) It sounded fine with one I used, but when I found the one with the amp, I thought I should use that one. When I did, I got a really big hum that wasn't there before. I used the one from my computer again, and the hum was gone. Don't know why, I am sure not an electrician :P. I am just happy it works =).
Well I'm not an electrician either (yet, im goin to U of M to be an electrical Engineer) but a loud hum from a power chord usually means that you are trying to run either a AC or DC current through the wrong chord (Also AC or DC).. or there could be other things.

Well I'm glad your amp works and that I could busy you long enough until you figured it out.
I'm not damaging the amp or anything by using this cord, am I? I mean, it fits in and looks the same. No strange noises or anything.
No I've used spare computer power cords to run my amp before, but it's weird that the cord that came with your amp creates the hum, but the spare computer one doesn't. Maybe it was just a defective cord...
It was a Blemished item. Maybe that was them blemish I couldn't find a scratch anywhere else.
Well those IEC power cords should be up to spec to handle the power coming out of your wall despite what it came from (unless its somehow some ghetto cheap chinese one made out of high gauge cable )

I'm no expert here, but I don't think most power cables are shielded. And maybe if there is something else running in your house (like a vacuum cleaner) that strains the rest of the electrical system of your house it could cause some fluctuation in the AC mains that creates a more uneven DC voltage in your amp and more uneven heater voltages.