Cook 'em or keep 'em?

[Securb]

I've been practicing a lot and focusing on our next set of songs. The Classic 20 has been on pretty much all day, as I don't think an hour passes without me picking up the guitar. I figure it's better for the amp to leave it on or in standby mode rather than constantly turning it on and off throughout the day. I just installed brand-new Mullard tubes and want to avoid replacing them sooner than necessary. That said, with all this playing, I imagine the tubes are going to rack up significant mileage either way. What are your thoughts?

[jeremy]

how hard are you running the amp? if you dont run the volume up, they should last a good long time

[uOpt]

The issue of heat cycles versus contiguous heat wrt longevity is as old as engineering itself.

I recommend you get a second same amp and do the opposite to it. Then you know

[Seashore]

I've had techs tell me both things. Personal experience, I've left the VHT on for hours by accident sometimes, and I think the tubes got noisier; I've left the Traynor on by accident and it's been fine. So I guess I'd say get a Traynor.

[Securb]

how hard are you running the amp? if you dont run the volume up, they should last a good long time

Not loud at probably as loud as someone speaking. The gain is dimed.

[jeremy]

those things will last for a long ass time

[80's_Thrash_Metal]

I turn mine on and off all the time.
Never gave it a thought.

[Mincer]

I've read all sorts of contrasting info about this...many times there are opposing views from people I trust. So, I might not do it with the master dimed, but if it isn't, everything would probably be OK.

[Rex_Rocker]

how hard are you running the amp? if you dont run the volume up, they should last a good long time

On that topic... kind of a related question.

I used to have an Orange Dark Terror at the same time I used to have an EVH LBX. The Orange was cathode bias. The EVH was fixed bias. Both were 15W and ran a pair of EL84's. I did notice the Orange ran the tubes hotter. I could tell because the red writing on the tube was staring to get brown and darker. The EVH was still bright red. Both got retubed at the same time.

Does it matter if it's cathode bias how loud you run the amp? Or is it running the tubes super hot at all time? I vaguely remember reading that, but I could be remembering wrong.

I do know the Peavey mini heads are fixed bias, if that makes the OP feel more at ease.

[Securb]

I will leave it on and just toggle the standby throughout the day.

[beaubrummels]

FWIW I had a reputable studio engineer (this guy worked on Metallica's live album) tell me it was better to leave the amp on, that most of the damage was in the initial spike when powering on. But when I left my amp on, even standby, half the tubes cracked the glass letting oxygen in and fried within 3-6 months. After 2 sets of expensive NOS tubes in 6 months, I just turn the amp off when not playing and turn it back on when I will play. I haven't been required to changes tubes in the 15-20 years since.

[jeremy]

On that topic... kind of a related question.

I used to have an Orange Dark Terror at the same time I used to have an EVH LBX. The Orange was cathode bias. The EVH was fixed bias. Both were 15W and ran a pair of EL84's. I did notice the Orange ran the tubes hotter. I could tell because the red writing on the tube was staring to get brown and darker. The EVH was still bright red. Both got retubed at the same time.

Does it matter if it's cathode bias how loud you run the amp? Or is it running the tubes super hot at all time? I vaguely remember reading that, but I could be remembering wrong.

I do know the Peavey mini heads are fixed bias, if that makes the OP feel more at ease.

cathode bias does run tubes hotter than fixed bias, but im sure it matters how hard you push em? it also matters how hot they are biased in either case. cathode biased amps may be "self biasing" but they still want to see a tube within a certain parameter to perform their best. ive changed cathode bias caps before to change the range, but usually not necessary

[Securb]

FWIW I had a reputable studio engineer (this guy worked on Metallica's live album) tell me it was better to leave the amp on, that most of the damage was in the initial spike when powering on. But when I left my amp on, even standby, half the tubes cracked the glass letting oxygen in and fried within 3-6 months. After 2 sets of expensive NOS tubes in 6 months, I just turn the amp off when not playing and turn it back on when I will play. I haven't been required to changes tubes in the 15-20 years since.

Which amp Beau?

[Ascension]

Word from experience with the Mullard EL 84's. I have several EL 84 amps and have run them in 3 different amps. If the amp is cathode biased like one of the Boogies and runs hot those do not hold up well, Love the way they sound in my JCA 22 H Jet City head but would have a spare set on hand if you are running those. Depending on the amp design, they may be fine with your Peavey Classic, but one of the simo-class Boogies will kill those very quickly. Those also break up rather quickly when you push them, which can sound amazing in an amp like my Jet City, but not so much in my Boogies or the Zinky. Been gigging EL 84 amps out hard for years, so have a little insight on these. Best all around new Production EL 84 I have used was the old TAD bigger bottle STR tubes but they are evidently NLA. I have Boogie s in my old Subway Rocket and just dropped a new set in my F 30. My last pair of the TAD's is now in my Zinky Blue Velvet.
If I were to buy a new set today for my Velvet I would likely grab the Tungsol set because they are the closest I can find to the old TAD STR set. They have a higher current capacity than most EL 84's and should be very reliable. However they run a slightly bigger bottle that won't fit in some amps.
These

https://www.thetubestore.com/tung-sol-el84-6bq5?page=2