Tube power amp - keep on continually?

I am wondering if there are advantages to leaving tube equipment, such as amps and preamps on continually. I currently own a pair of Rogue M-120, and will turning on and off the m-120 shorten the life of the tubes? If so, to what extent?

Best Regard
Alan Leung
preamps are good left on continuously for best performance but power amps isn't a good idea the consumption of electricity is pretty high and the effect on the life of the tubes just doesn't justify the performance gains. Besides 30 minutes it takes to reach full performance isn't really that big of a difference anyway.
This is just my guess, but if left on 24/7, I bet you'd chew through amplifier output tubes every six months. With normal 1-4 hour listening sessions then leaving the amps off when not in use I imagine you'd get 2 years out of a set of output tubes.

Tubes don;t like being turned on and off (like everything else), but letting then burn 168 hours a week with little use is is sort of silly. This applies to amp output tubes. line level tubes like those found in preamps and phono stages generally last longer and cost less to replace (uses less electricity and heat your house less), so you will generally see people suggest that you keep them on (if not 24/7, then at least during the periods when you listen the most, like weekends, holidays, etc)
As others have said, being on all the time ages the tubes prematurely, but on/off cycles are probably harder on them than just being left on.

I compromise - I turn my system (amp, pre and DAC - all tubed) off every night during the week, but I leave them on all weekend. I figure this works out best, since I often don't listen for a couple of days during the week. This regime minimizes the on/off cycles and the amps are always up to speed when I want them on the weekends. While the power tubes only take about half an hour to warm up most of the way, the amps really only sound their best once they'be been on for an hour and a half or so.
I agree. Do NOT leave tube power amps fired up unattended. Proper use calls for a warm-up time ( 5 - 15 minutes depending on design ) prior to use and then a "heat-down" time prior to shut-off. Cranking signal from the tubes before they are fully warmed and / or turning them off before they've had a chance to cool off causes extra thermal stress on them, which leads to premature failure. Sean
Thanks for all the advice. I will turn it off when it is not in-use.

Sean can you explain cool down time before shutting the amplifier off? Like how long to wait? Never heard about this before? Would this apply to a class A triode tube amplifier also?
Cool down time, may be that is why everything I turn off the amp, there is a "DIN DIN DIN" sound from the Rogue M-120, I believe is from the output tubes. Thanks Sean
Yep topvideo, that's probably the sound of the glass contracting as it cools. Similar to an aluminum engine block after your shut off your car. tink, tink, tink. except there its the metal.

My tubes to the same thing.
Aroc's comparison between tubes heating down and an engine heating down makes for a pretty good anology. Both have built in design tolerances, both require specific clearances / spacing for optimum operation, both are made up of a complex sum of parts that do their job individually yet sum together to form a team effort, etc...

Just like a motor, tubes run hot and certain parts run hotter than others. As the tubes heat down ( or "cool off" to normal people ), a small amount of internal shifting takes place within the tube itself. This has to do with the expansion and contraction of the metals due to thermal variances. The faster that thermal variances come into play, either heating up or heating down, the more likely severe shifting is to take place. The more internal shifting that takes place, the further the tube will be out of emmissions / tolerance and the less performance that you'll get out of it. That's because the design parameters of the tube are based on specific internal dimensions / proximity of conductors. When these dimensions & proximities change, even by a hair, it changes the performance / electrical characteristics of the tube.

This is why i suggested allowing a tube to gradually come up to operating temperature before hitting it with signal. The entire tube becomes thermally stable and levels out before stressing any of the individual components harder than others once signal is applied. While it is true that some components are under heavier stress than others inside of a tube, allowing them to warm up somewhat reduces the fatigue that they undergo. Think of it as exercising the tubes i.e. "warming up" before actually "working out". Yes, you can sweat ( build up heat ) doing both, but the stress level rises gradually.

As far as "heating down" goes, just as the tubes shifted internally from warming them up, they do the same thing as they heat down. If you get them really hot and then pull the plug on them all of a sudden, there's a bigger temperature swing to deal with as the tube cools off rapidly. Greater temperature swing in a shorter period of time causes more shifting / expansion / contraction within the tubes themselves, taking them further out of tolerance even faster. If you do this on a regular basis, your "matched tubes" won't be matched very long. Don't worry about that though, because nobody really matches tubes right anyhow : )

As you can see, warming up / heating down a tube based system, especially amplifiers where there is a lot of output and heat involved, can actually extend tube life AND provide more consistent sonics during that extended lifespan. This is something that everyone thinking about buying tube gear should be aware of before making the jump. When properly operated, tube gear IS more time consuming with more potential for degradation. This isn't to say that SS devices don't undergo similar thermal stress related problems, but it is nowhere near as severe or as rapid as it is with tubes. That's another story for a another time though kids as my fifteen minutes on Agon are up for today : ) Sean
All responses were excellent ,I was wondering about that too,a while back,and found the answer at AUDIO RESEARCH's website. Go to click on the "vacuum tubes" link,and read on.