Refreshing your amp’s set of valves??

Majorscale

I’ve had my Lazy J J20 for five years now and never changed the stock valves. It hasn’t been gigged much, maybe 6-7 times a year, but it has been played loudly at home a lot. It still sounds good but I’m wondering if like with a dull set of strings I’m losing something by not having refreshed the valves after all this time.

So, would you say I’m overdue a valve change and should see a tonal improvement?
How often do you change your amp’s valves?
How do you know they are due a change in lieu of an obvious fault?
Would you suggest a complete valve refit or just the power valves?

Maynehead

I’d be tempted to get a new set of power valves, just to see if it makes any improvement. If not, just keep one set as spares, they’ll come in handy sooner or later.

As for the preamp valves, they shouldn’t need changing unless you’re having problems. Might be useful to see what brand they are though, just in case there might be room for improvement.

jacksparrow

I have just re valved my jtm45/100 with a quad of GEC KT66 that i had lying around for a while but i had mixed them up with others and did not know which ones where matched.

So i finally got round to buying a maxi matcher tester and matched them up, when i measured the chinese ones i took out they are still testing good even after 560v on the plates, so fair play to the shunguang KT66, but the GEC just have this depth to them that the shuguang cannot match, also it reduced the floor noise significantly.     So like the previous poster said try new power valves.

So i am over the moon with the sound now pure CREAM with a Lester.

ecc83

Maynehead said:

I’d be tempted to get a new set of power valves, just to see if it makes any improvement. If not, just keep one set as spares, they’ll come in handy sooner or later.

As for the preamp valves, they shouldn’t need changing unless you’re having problems. Might be useful to see what brand they are though, just in case there might be room for improvement.

Not a bad idea but FCS do something nobody ever does! RECORD the amp as is. Play a few licks of various types and genres THEN fit the new valves (might need a re-bias?) record in the same setup.

Ok, not a double blind test by any stretch but a bit of disciplined listening should tell you if the valves have made any difference. Employ the ears of a friend as well.

My feeling is there will be little if any change. BTW just buy ONE decent ECC83 and try it in various positions, pre amp valves last decades but can eventually get noisy or microphonic.

Dave.

ecc83

Maynehead said:

I’d be tempted to get a new set of power valves, just to see if it makes any improvement. If not, just keep one set as spares, they’ll come in handy sooner or later.

As for the preamp valves, they shouldn’t need changing unless you’re having problems. Might be useful to see what brand they are though, just in case there might be room for improvement.

Not a bad idea but FCS do something nobody ever does! RECORD the amp as is. Play a few licks of various types and genres THEN fit the new valves (might need a re-bias?) record in the same setup.

Ok, not a double blind test by any stretch but a bit of disciplined listening should tell you if the valves have made any difference. Employ the ears of a friend as well.

My feeling is there will be little if any change. BTW just buy ONE decent ECC83 and try it in various positions, pre amp valves last decades but can eventually get noisy or microphonic.

Dave.

scovell001

Majorscale, as a lazyj owner I’d say yes put some new valves in there. It’s such a touch sensitive circuit.

theres a guy called valvetubeguitaramps.com who will match all the valves for you, bring back the sparkle !

jacksparrow

I would go NOS in a quality amp like that, probably last twice as long also.

LastMantra

My amp has has had same valves for about 50 years 

breadfan

@Majorscale Are you in the Lazy J Facebook group? Someone asked a similar question last year & Jesse said valves should last around 1000 hours in the J20. If you decide to change them, he's also recommended EH valves from Watford Valves.