Does valve 'wear' affect volume..??

[bigdawg]

Ok Ive got a Mesa Express 5:50 which is pretty much left on the Blues and Crunch settings.

The other day I switched to the Clean setting and the volume jump was mahoosive... Did the same with the blues / Burn modes and again the volume jump was huge..

I dont recall the volume differences being as severe when I fitted the tubes, would leaving them in these modes (for over a year) cause 'wear' and volume loss???

[ICBM]

No, because the same valves are in use in the different modes - and even if it did, it would affect the high-headroom modes more than the low-headroom ones. Valve wear can affect output volume, but only really for power valves.

The huge volume difference is the reason the modes aren't footswitchable on Mesa amps, despite people asking about it almost on a daily basis over on the Mesa forum - or at least they used to... it seems to have sunk in as to why not now.

There are some combinations of control settings where it's less drastic than others, so maybe you're using slightly different ones now. Or you just forgot what it was like .

Edit: actually I suppose it is possible, if you're running the treble controls higher now than you did, to compensate for dull valves. You might then get more of a volume jump. It's still not *because* you've been running it in those modes though.

[Sir Axeman]

This thread caught my attention cos I wondered if that was the case? What made me think this was my handwired AC30HW2X was noticably louder than my 2003 AC30TBX say I had the TBX on 5 on the volume the handwired would match it for volume on say 4!! It sounded pretty much the same sound (comparing the normal channels with the handwireds bright switch off) but was just well...1 louder! Why?

[bigdawg]

No, because the same valves are in use in the different modes - and even if it did, it would affect the high-headroom modes more than the low-headroom ones. Valve wear can affect output volume, but only really for power valves.

The huge volume difference is the reason the modes aren't footswitchable on Mesa amps, despite people asking about it almost on a daily basis over on the Mesa forum - or at least they used to... it seems to have sunk in as to why not now.

There are some combinations of control settings where it's less drastic than others, so maybe you're using slightly different ones now. Or you just forgot what it was like .

Edit: actually I suppose it is possible, if you're running the treble controls higher now than you did, to compensate for dull valves. You might then get more of a volume jump. It's still not *because* you've been running it in those modes though.

thanks for that - Dont go on the mesa site, didnt realise it was a common thing.

Just the other night went from crunch to clean with my tele and I swear paint started peeling off the walls!! But your right I do run the treble higher as I find it to be a really bassy amp (say treble 2oclock, mid 12 & bass 10)

ta...

[ICBM]

This thread caught my attention cos I wondered if that was the case? What made me think this was my handwired AC30HW2X was noticably louder than my 2003 AC30TBX say I had the TBX on 5 on the volume the handwired would match it for volume on say 4!! It sounded pretty much the same sound (comparing the normal channels with the handwireds bright switch off) but was just well...1 louder! Why?

Probably just a difference in the circuit or the taper of the pot. If it's not the exact same circuit you don't know if the volume control settings relate at al.

Is there any difference in volume when they're both up full? (Or at the exact point of power-stage clip.) That would be more indicative of a real difference.

[Sir Axeman]

...hard to say now cos the TBX is gone to its new home. Oh well i may never know but still as long as it sounds like its supposed to tis good. That 12v pilot bulb still goin strong to!

[ecc83]

Probably just a difference in the circuit or the taper of the pot. If it's not the exact same circuit you don't know if the volume control settings relate at al.

Is there any difference in volume when they're both up full? (Or at the exact point of power-stage clip.) That would be more indicative of a real difference.

Do other amp makers not make AC specification tables available to bona fide techs?

Without such data I really don't see how an amp can be checked for the correct gain and voicing. It would of course make comparing the two amps in question fairly easy.

Dave.

[ICBM]

Do other amp makers not make AC specification tables available to bona fide techs?

Not many, at best. The most you normally get is a few AC voltage readings at different parts of the circuit with specified control settings. Even those aren't always very accurate.

Without such data I really don't see how an amp can be checked for the correct gain and voicing. It would of course make comparing the two amps in question fairly easy.

One problem is pot tapers, which are subject to wide tolerance (not just the overall track value) with the cheap types used in most guitar amps. So unless you're comparing measurements with all controls up full, it's pretty difficult to tell for sure. That doesn't help much if you're trying to find out why one amp seems quieter than another "with the volumes set to 5" or whatever. It could easily just be a pot variation.

Especially with vintage amps, "some just sound different to others", or "break up earlier" or whatever. I long ago stopped trying to fix this, and as long as the amp sounds "good" then it is considered to be working fine . It's just too much work to do otherwise.