Changing tubes?

[straycat]

Fire it up and take something not conductive like a paint stick and tap on the tubes gently and see if the noise goes away.
If you tap on one and the noise increases you have a bad tube.
If your power tubes don't light up all the way it can cause a hum new or old they can go bad just sitting there.
I had that kind of noise in my Blackstar HT 20 head and I did some tapping around and saw one power tube just glowing at the bottom so I replaced both and she sings just fine now.
Pre amp tubes take all the punishment so maybe you got a bad one.

[DonP]

Whenever I hear you need to replace tubes every year I recall the bass player in my previous band who had a 1968 fender bassman with original power tubes, and they sounded fine!

+1 I'm still using the original tubes in my DSL100 I bought new in Nov 1998. 1 tube died the first month - I replaced that one (OMG - not a matched set! ). Everyone who plays my amp says it sounds awesome.

And it's not for a lack of tubes. I have a basement full of NOS and GT EL34's, RCA 12AX7's new in box, etc.

Don't fix it if it ain't broke. Who tells you to change tubes every year? Tube companies? And what do they do? Sell Tubes?

OP - Go out and buy a set of new tubes. If you really hear a tonal improvement, dump the old tubes. Otherwise I'd say keep using the old tubes and keep the new ones safe and try it again after you put more miles on the old tubes.

[ZL1hawk]

dvscool this is worth a look to make biasing your amp, or at least checking your bias, very easy. http://www.compu-bias.com/

Nobody likes the price on them but they do love the convenience. They can be had for less with a little savvy shopping around.

+1 I'm still using the original tubes in my DSL100 I bought new in Nov 1998. 1 tube died the first month - I replaced that one (OMG - not a matched set! ). Everyone who plays my amp says it sounds awesome.

And it's not for a lack of tubes. I have a basement full of NOS and GT EL34's, RCA 12AX7's new in box, etc.

Don't fix it if it ain't broke. Who tells you to change tubes every year? Tube companies? And what do they do? Sell Tubes?

OP - Go out and buy a set of new tubes. If you really hear a tonal improvement, dump the old tubes. Otherwise I'd say keep using the old tubes and keep the new ones safe and try it again after you put more miles on the old tubes.

Marshall's are freaks of nature, I had a JCM 800 that served double duty as a beer sponge and an ashtray. No joke. The amp is alive and still working to this day even though it electrocuted 2 people in a ill advised restoration attempt. That particular monstrosity is the Michael Myers of the guitar universe.

Yes those 2 people survived.

[Newc]

What scares me about that pic is the amp going straight to the wall. No surge protector? No line regulator? Dude, for real?

[DonP]

What scares me about that pic is the amp going straight to the wall. No surge protector? No line regulator? Dude, for real?

Matt,

It's an old picture and it is in a surge suppressor now.