How should you treat your tubes?

Ekobesky: Thanks for the response. I was feeling guilty either way. Now you make me feel less guilty leaving them on. JBNorth1178

With my tube amp I have a "four hours" rule. Which is, if I'm going to go back listening within "four hours" I leave the amp on. Truth is, when I know I'm going to be listening I turn the amp on for 10 - 15 minutes before hand to warm the tubes up, but I also know it'll generally going take about an hour for the amp/tubes to start delivering their best performance. It really is a case, of patience being rewarded.

Here's some great advice from Kevin Deal @ Upscale Audio (www.upscaleaudio.com):

Tube Life, noise, and do I leave the power on -

We get asked this question a lot. With a power amp…you would typically not leave it running 24 hrs a day. Power amps produce heat, and they use a bit of electricity. Pre-amps, DAC’s and other products that use small tubes are another question. Regardless of what anyone tells you…I have not found a definitive answer to this question.

Tubes age in a couple ways. One is they lose emissions over their lifetime. In other words, they run out of gas. Or better yet steam…as they don’t just "quit" but lose their drive capability gradually. If you figure a tube like a 12AX7 or 6922 to be good for about 10,000 hours, and you leave it on 24 hours a day…well…you do the math. There are 8,736 hours in a year. So when did the tube go bad? It depends on how picky you are. It’s like a tube of toothpaste. Kinda peters out at the end but it seems you can squeeze out a little more. Some products (and audiophiles) are more picky than others. I recommend to folks that want to upgrade to premium new old stock tubes that they do it while their stock tubes are good. That way you have the cheap ones working and available should you decide to sell the pre-amp.

The other way they age is to become noisy. The noise will sound like popcorn popping softly in the background, or it may become a roar, and it can happen to any tube….including new ones. The most common reason that I have found for tube noise is the coating on the filament becomes compromised. This can be made worse by turning them on and off a lot. That’s the best way to guarantee trouble with tubes. Some products have filaments that are left on even when the product is turned off. This is a good idea and reduces that shock and keeps your pre-amp in a "warm" state. Other than that….maybe a mixture of a total power off if you will be gone a day or so, and leave it on when you anticipate you will be listening.

For a stretch of an hour or two, I would not turn off either, certainly not the preamp anyway.

Beyond that kind of time, a lot of different considerations come into play. Not only is the life of the tube at issue. Heat can damage other components, so leaving on tube gear, particularly if the tubes are enclosed or if you are dealing with hot output tubes, can result in shorter life for such components.

Other considerations include whether the equipment has "soft start" circuits (slowly brings up circuits so thermal stress on tube filaments are reduced) or if the power supply employs tube rectification (also results in slow turn on). With such slower turn on, the issue of wear from the turn on part of the cycle is reduced.

Probably the best answer would be that provided by the manufacturer.