When to service tube amp??

I've had my Fender Deluxe for around 8 years with no maintenance or cleaning or whatever the fuck. How do you know when its time to change tubes or give the amp a checkup...besides when it stops working?

Well, after 8 years, (and im sure you play quite a lot) you are long overdue for maintenance, let alone a cleaning! lol

It's best to just change tubes at regular intervals, if you have a pretty consistent play schedule.

Otherwise, only your ear (or that of you band mates) will clue you into knowing its time for a re-tube.

As tubes age they tend to leak - air gets in and then they fail.
Look for a blue glow near the base of the tube - assuming the amp is inverted.
You'll also hear more hiss as they age.

I don't think I'd go much more than a couple years without re-tubing, but your ears should tip you off as to how your tubes are holding up. I find tubes lose their clarity when they get old, and they lack the punch they once had. If they're on their last legs the signs will be more obvious. Sound may fade in and out, you may hear a low rumbling sound if you have a bad power tube, or if you have a bad preamp tube you might hear a high pitch whine.

wahts the standard price for amp maintenance?

For guitar it's pretty much between 50-70 for the works. What about amps?

As tubes age they tend to leak - air gets in and then they fail.
Look for a blue glow near the base of the tube - assuming the amp is inverted.
You'll also hear more hiss as they age.

I...don't think this is true. There are NOS tubes from the 50s that haven't leaked. Typically, tubes won't leak unless they're mishandled. They basically blow the tube around the filament, and since glass doesn't shrink or change shape very quickly, it ain't gonna leak.

I could see this happening in a 1000 year old tube...but there's not many of those around. :)

It is true that the blue/white glow is caused by gas in the tube, though. The normal dark blue glow, however, is just electrofluorescence, from electrons hitting the glass. There'll also be a red/white glow from the heater filament that heats the cathode.

There's some guys who are serious about this stuff...lots of info at Blue Glow in Electron tubes (http://www.jacmusic.com/html/articles/blueglow/blueglow.htm) - check it out.