How often do you change valves

[Woko]

I have had my valve amp two years it gets used most days but not gigged to often

[Steven Lister]

I've been loosely tracking valve life in my stock VJr. V3 --- up to around 180 hrs. on Tung Sol 12AX7/ECC803S and JJ EL84 and going strong. Paid $26 --- that's only 14.5 cents an hr. (& dropping daily) for ENTERTAINMENT THIS GREAT!!

(edit - BTW most of that 180 hrs. is at 1 o-clock-to-max level and about 1/2 w/distortion up front)

 

You didn't tell us what your amp is (looks like a tweed something SE or A/B?) and what type valves?

 

Hit every BLUE NOTE baaaby..., I'm going to play on:-"

[m-theory]

Short of catastrophic failure, it's nearly impossible to tell when a tube is drooping, unless you're familiar with what that sounds like, and of course, that's different with every amp. The problem is that tubes generally fade so slowly that our ears adjust along the downward curve, until there's finally either a shorted filament or a tube goes gassy and the failure becomes VERY obvious.

 

You often hear guys brag about a vintage amp of their's that has "40 years on the same tubes, and still going strong," or something along that line. These are the people who, when they finally DO have the amp serviced, report "Wow, the amp has never sounded so strong!" No kidding. Do ya think 40 year old tubes might be dull?

 

My general rule of thumb w/new production tubes is to replace them every 6 months, when I'm using the amp regularly. The swap is a noticeable difference at that point, if you're playing fairly often. If you're not, you can get by a bit longer. A lot depends on how and how often you use the amp. If you're running it no higher than 9:00, and only once a month for 30 minutes, you'll get years out of new production tubes. If you're playing it 4 hours per day, every day, at full throttle and boosted, you'll probably chew through output tubes in a month.

 

Btw, it's generally the output tubes you'll have to replace, not preamp tubes. Unless those get noisy, it's very rare for them to short out, and they don't often wear out.

[Woko]

Thanks folks for your replys. the amp started to distort last week in the second half of a gig when I tride it again at home it seemed fine.

[scott58]

I've been loosely tracking valve life in my stock VJr. V3 --- up to around 180 hrs. on Tung Sol 12AX7/ECC803S and JJ EL84 and going strong. Paid $26 --- that's only 14.5 cents an hr. (and dropping) for ENTERTAINMENT THIS GREAT!!

 

You didn't tell us what your amp is (looks like a tweed something SE or A/B?) and what type valves?

 

Hit every BLUE NOTE baaaby...' date=' I'm going to play on:-" [/quote']

 

Thanks bud, that's good to know.

[cGil]

I have a couple of RCA 12ax7's that are muddy as hell. They were "pulls" long before I got turned on to 'em.

 

I've had Sylvania 5751's in a pair of matched turreboard Fenderish VJr's for about a year and a half, and those tubes were used for 7 years in a Mesa Formula preamp before that. Last week I just tried some fresh JAN-Phillips 5751's, and couldn't tell the difference with a direct comparison to the Sylvania in the other amp. Not too shabby if you ask me!

 

Gil...