I leave my JP80 on all the time, unless I'm going to be out for an extended time. It may or may not shorten tube life; some believe that the constant starting up of the tubes is more wearing on tubes than leaving them on continuously. If you get good NOS tubes, they will last a considerable time in a well-designed preamp. I recently took out some Tele 12AX7s from my preamp (replaced them with Tele 803Ss, reputed to last even longer) after having them in there for almost two years and they still tested very strong and quiet. Make sure you keep the pre muted, in case of a power outage.
I agree with RC. Nuff said... Sean
Excuse me while I go knock on a piece of wood... OK, that done, I've had wonderful luck leaving my preamp on 'all the time' for nearly a decade. I only power it down for moving or cleaning. Oh, did I mention that I've never had to replace the tubes?!? Way to go Michael Elliott (Counterpoint).
24/7 operation definitely shortens tubes' life in ALL cases.
Moreover your electricity bill grows.
Unswitching tube components after the tubes rich the steady state(10...15min for preamps and other small signal tube components) will NOT shorten the tubes' life.
Switching back tube components after they've riched an initial state(5...7min for preamps and other small signal tube components) will NOT shorten the tubes' life.
Under the initial state we should define the state when no emission of electrons takes place from cathode i.e. the tube is literally cold including the tube base if such exists.
The positive issue living 24/7 tube component operation is that your system is always ready to play. Some components improve the sound during staying unoperated for another hour after the steady state but only on couple of small quantums of relative improvement(Someone recently posted a thread about quantum-tweaking units:^)-).
The power tube amps can be maintained the same way with 1.5x...2x longer intervals(think logically!).
These thoughts shared with me by VTL customer service and they realy work.
IMHO it doesn't make a sence to live components overnight without work.
I often call the babysitter to turn my tube-rig on(just only one button) when I finish working so I can come and listen.
My Moscode Super-It (3 l2AX7s) came with explicit instructions to leave it powered on at all times. To reinforce this, it doesn't even have an on-off switch. Harvey Rosenberg claimed the tubes would last for a minimum of 3 years left on 24/7. I've had it for over l5 years, have never blown a tube, and have replaced them every once in a while out of some feeling that I ought to, but the pulls have always tested good. As they say, YMMV.
Small-signal tubes are usually rated for about a 10,000 hour lifespan, give or take. They will often last a lot longer, but they start to get noisier and sonic quality does start to degrade. So if you leave your preamp on 24/7, 10,000 hours is reached in a little over a year. If you are willing to retube your preamp every year, then no problem. Otherwise, turn it off when not playing, and you'll probably get 10 years or more of tube life. Power amps are even worse, with output tube life of a few thousand hours and much higher replacement costs.
I have a question. Do you guys turn your stuff on and let it sit for the warm up period before passing a signal through it?
It seems to me that waiting an hour for an amp to warm up is a bit extreme.
I guess what I'm really asking is will it harm the Amp/pre-amp to start listening to music while the tubes are still cold/unstable?
Thanks in advance. I'm a little new to the tube game
If you put a signal through a tube before it reaches operating temperature, you will know it. It sounds HORRIBLE.
Having said that, once you turn on a tube set and the filaments begin to glow, you are ready to operate in well under one minute. Give it a minute just to be sure though. The sound might not be near as good as if you let it idle for a bit longer, but why waste time when you can be listening to tunes ? Try not to "throttle" stone cold tubes though, as this is when you are most likely to do damage to them. That or getting the plates cherry red by overdriving them or having a bias problem.
Keep in mind that this is a broad generalization. Some tube gear might have soft start or circuitry that delays the firing of tubes to minimize in-rush current. Read your manual and go from there. Sean
Had a VTL TL 2.5 myself for about two years, and I pretty much left it on all the time except when I knew I was going to be away for a couple of days or more (and then I'd usually turn it off and unplug it). From all that I've heard from VTL and read about their gear, they seem to recommend such an approach. Now I've got a Rogue 99, and they've got a deliberate soft-start circuit to protect the tubes at power up and explicitly suggest that you turn the thing off when you're not using it in order to prolong tube life -- so that's what I do. Which is right? No idea. I've blindly deferred to the fellows who designed the stuff on this one.
Glen, to answer your question -- certainly Yes you should leave your tube rig for at least an hour (especially if you have tubes on the front end) before you will pass the signal. You can clean vinyl or CDs or write bills or have a quality time before you will start listening:)
I must say, that I find M's waiting stand a bit exaggerated, but find RC's and Sean's advice sound. RCprince, you lucky So and So, where did you manage do lay hands on ECC803 teles???!!! Cheers,
Detlof: A friend who also sold me that mother lode of Gold Lion KT88s. He's a contractor, and every now and then he's between jobs and lets a few of his stash go to me. In this case, I had to trade some Tele and Siemens Ccas to get them; if I ever can fix my phono stage in the Jadis, I'll have to go searching for more Ccas, I guess, although the Lamm works incredibly well together with the 80's line stage. I am very surprised at the improvements I've heard since I put the 802S and 803S tubes into the amps and preamp; had very good Tele 12AX and AU7s in there before and these are a clear level better. No wonder they're so sought after.
In answer to Glen's question, in addition to the advice given above, some preamps have auto-muting circuits that will not let the signal through till the unit has stabilized (for example, 6 minutes in my Jadis, another reason I don't like to turn it off!); that gives the tubes time to stabilize and get to operating temperature. I tend to agree with Sean's and Detlof's advice--I leave my Jadis amps in standby to warm up a good 5 minutes to an hour before I listen seriously, but I can and do pass signal at a very low volume level after a few minutes while they're warming up and use it as background music (or, if it's very simple and quiet music, I can listen seriously to it, even at the 1-2 watts the Jadis put out in standby).
Thanks guys, now I don't feel like it was such a dumb question. Gotta go pay some bills now while my tubes warm up. :^)
Thanks to all of you for your responses. Valid arguments on both sides! I'll probably just move my Mccormack preamp out to my HT system and use all of the great advice for the VTL on my music only system (but only if the sound quality is not significantly altered).