A couple of tube questions

I have a Vox AC15 Treble Boost amp, and was wondering how far it can/should be pushed in terms of volume. I ask because I often have to share gear with other bands at gigs. At our last show, the guitarist in the headlining band had every knob on the amp up to maximum; not only did this result in a pretty awful sound, I didn't take too kindly to him taking liberties like that. Is this an overreaction, or can the amp not handle it?

Also, I've had said amp for about 5 years, using it about once a month - is it time to change the tubes? I know very little on the subject... is it one of those things where I won't know how much they were needed until I've changed 'em?

I have a Vox AC15 Treble Boost amp, and was wondering how far it can/should be pushed in terms of volume. I ask because I often have to share gear with other bands at gigs. At our last show, the guitarist in the headlining band had every knob on the amp up to maximum; not only did this result in a pretty awful sound, I didn't take too kindly to him taking liberties like that. Is this an overreaction, or can the amp not handle it?

Also, I've had said amp for about 5 years, using it about once a month - is it time to change the tubes? I know very little on the subject... is it one of those things where I won't know how much they were needed until I've changed 'em?

No overreaction. Don't share your gear at gigs. You have no control if someone abuses it. And someone will. Let them use their own. If they don't have any, TS.

As far as changing tubes, I wait for them to go bad. I think they either work or not, no middle ground.

I'd try to find a radio/TV repair shop in your area.
Call first to see if they STILL have a tube tester?
I've heard horror stories of bad tubes taking out resistors, etc.

Steve

EL84s have a reputation for going bad hard & fast, unlike bigger bottles, which seem so start sounding cruddy in advance of their demise. I don't gig as a guitarist, but I'd never gig an el84 amp w/o a spare set of tubes, though to be fair, I'd probably not gig ANY tube amp w/o spares.

As to the spec of the amp, I've never heard of any Voxes being prone to failure, and in fact, Brian May runs his AC30s flat out virtually all the time. Course, that might be why he rolls with 8 of 'em.

There are times you'll have to share gear. Just have a quick word with the person with whom you're sharing about 'keeping it under control'--setting some parameters, as it were.

Local TV repair guy has a tube tester of some sort in his shop, on display, but no one there knows how to use it, it's more like a "This is what we used to hafta do" thing. Won't come off it, either.

get a spare set of JJs and swap 'em out with the tubes in your amp - does it
sound better or the same? that's how you can decide if you need new tubes.
(and, if you don't yet - at least you'll have the replacements on hand for
when you will need 'em)

power tubes, the EL84s, I mean - your preamp tubes will last much longer
and prob'ly won't need replacing as often.