Tubes on 24/7...Y/N?

[lwhaples]

Turn em' on when I get home. Make coffee,check in on the Forum then on

goes the Blueberry,then the tuner. LP's get to spin after 8:00

till bedtime.

Larry

[jazman]

My Moondogs are usually on 24/7. In 5 yrs of ownership, I've replaced one vintage 2A3 RCA blackplate that became noisy, and one GZ33. Since that time I use GZ34's almost exclusively. My line preamp goes to standby sometimes, and my phono preamp is also usually on 24/7. "All" of my tubes are high cost to purchase or replace NOS brands like Mullard/Amperex/RCA/Brimar etc. Road trips and vacations are usually the reason for the amps being turned off. Maybe it pays dividends to use premium tubes? Maybe I'm lucky? (NOT!!) I've never worried about tube burnout. Instead, I accept it as part of the cost of ownership for the higher quality audio that is returned.

Then again, I live in the same county where the 100 yr old light bulb is still burning.

Klipsch out.

[Audible Nectar]

I am in the "off when not in use" camp. I let my Mcintosh tube gear warm up for about 20 minutes also - best sonics are realized in about an hour.

I also see I am not the only one who tends to avoid running the tubes during heavy AC season/heat. In addition to being counterproductive to climate control, I too am wary of running my vintage amps on "restricted" power due to heavy AC usage. For this reason, I have thoughts of investigating a power regenerator for stable and consistent power to my tube gear.

Since my amps are also cageless (MC30s), I also feel more comfortable having the amps off when I am not at home. While it is highly unlikely that there would be an issue, I do believe in safety first, and being absent the worry. For my three-four listening sessions per week, I can live with the warm up time - it's a habit now, kind of like preheating the oven or grill before cooking. If I plan to listen to my gear after work, for example, I turn my gear on when I get home then change as it warms up. I have my "VRD/Peach" owning friends in the same habit.

[Travis In Austin]

Power amp and preamp off after listening. I find that I only get about 2 to 3 nights of listening in during the week. On the weekend they get turned on in the a.m. the off at night. The Nottingham turntable is designed to be stopped to change lp's, yet the motor continues to run, so no real issue there.

Travis

[pauln]

I think I started this with my question in another thread. I am surprized by the on/off crowd. Of the three arguments against 24/7 power up (tube life/cost, power consumption/cost, safety), I think safety hazard and electricity waste might have a case, but their weights will vary with the experiences and expectations of the individual, and their particular gear.

The hours of life ratings for tubes is the expected total life when running the tubes at their maximum specification limits. In audio systems this rating will be greatly understated as tubes do not approach their limits when you are not listening, and may never do so when you are listening, but may do so when you are listening for breif moments.

This means that small signal tubes in the preamp may last forever at power, and power tubes rated for a few thousand hours may last for decades.

I think the energy consumption argument is a strawman when tube power use is compared to the consumption of household appliances, especially the AC. Or the price of gasoline.

Heater burnout in tubes is uncommon, and as the temperature of the internal elements (particularly the anode) is cooled by direct radiation rather than convection, if your tubes are mounted on top of an uncovered chassis (so that they are not enclosed by radiant barriers) they will not be subject to excessive heat buildup. The temperature of the ambient air and the use of 'cooling rings' and fans don't help the tube because those techniques of cooling are based on convection. Fans may be used to keep other things cool around the tube, but the tube cools by radiation so it needs line of sight to the large space around it.

Putting tubes through a power cycle of turn-on and turn-off is an extreme experience for a tube and although breif it may incrementally damage it in various ways that shorten the tube life. The internal elements do not reach operating temperature at the same time, so there is a period during which the tube specifications may be misaligned and rating limits may be surpassed. The temperature changes experienced during physical warm-up alter minute geometries and micro-positions of elements via differential thermal expansion that effect the operating characteristics of the tube and may eventually weaken some structures like the seal around the pins in the base.

Tubes are tough and made to operate within spec when hot and operating in a stable circuit all warmed up. In amatuer radio, those of us that use tube transmitters always keep them warmed up (on stand by) all the time. It is good for the capacitors, too.

An analogue might be the air plane. When the plane is in the sky flying, you may press the pedal, push the stick, and change the throttle with predictable effect. Your controls work correctly and you can make the plane go up and down, left and right, bank steep turns, and if you have the right plane and the skill, you can even do rolls and loops. This is like a tube that is operating at temperature.

To continue the analogue, turning on and off a tube is like take off and landing. These are the most dangerous times for a plane. It is also when your degrees of freedom are most limited in terms of what control options are available to you. You can't bank turns on or just above the runway. You get the idea...?

I am more worried by thoughts that my water heater will leak, my dryer will catch fire, or my front door key will break off in the lock, than I am about my tube amps doing anything exciting by leaving them powered on. I have had the same power tubes in place running for four years and if anything they sound better with time. I can replace them for $50 a pair (Sovtek 2A3).

[Parrot]

An analogue might be the air plane. When the plane is in the sky flying, you may press the pedal, push the stick, and change the throttle with predictable effect. Your controls work correctly and you can make the plane go up and down, left and right, bank steep turns, and if you have the right plane and the skill, you can even do rolls and loops. This is like a tube that is operating at temperature.

To continue the analogue, turning on and off a tube is like take off and landing. These are the most dangerous times for a plane. It is also when your degrees of freedom are most limited in terms of what control options are available to you. You can't bank turns on or just above the runway. You get the idea...?

It would be extremely wasteful to keep an airplane flying 24/7. You'd have to refuel in the air, always a dangerous proposition. Does the plane fly any better when it's been in the air for, say, a month straight 24/7, than when it has been flying for an hour? The answer is No, and neither does a tube amp that has been on for a month straight sound any better than if it's been on for an hour.

[jt1stcav]

Does this answer your question?

[Clarence]

[li] careful kitty...

[Parrot]

Does this answer your question?

No, not really.

[jt1stcav]

Well then, Paul, let me clarify...my li'l kitty doesn't sit between my tube gear when it's on, for obvious reasons, natch. But when it's shut off (when I'm not home listening to it or when I go to sleep), than Sammy will jump up there and make herself comfortable. She's not too fond of red hot tubes, and I assume your cat isn't either.

And I thought a picture was worth a thousand words...must've been the wrong picture![]

[Seadog]

I never leave tube gear on overnight or while away from home.

[RAPTORMAN]

Does this answer your question?

No, not really.

If that's an SET, that cat would be happier--More heat[]

[jt1stcav]

It's a 300B SET amp and plenty hot (along with the 6SN7 linestage pre), but she's not interested in its heat...she doesn't even sit in the sunlight like most other cats![]

[Parrot]

I guess the VRD doesn't run as hot? because my cat used to sit there every once in a while even while the amp was on. I have a different stand now, though, so there's not enough space for her.

[DRBILL]

Some 26 years ago I served a parish that had Schulmeric chimes in the tower. This is the system that has small tuned rods that are tapped by a tiny hammer and the resultant tone greatly amplified and broadcast through horn speakers.

This system also had Westminster chimes that reported each quarter, and tolled the hour.

The amplifiers had a jumper that allowed the heaters on the parallel P-P 6L6s to remain on constantly or to come on five minutes before demand.

According to the service records, the "always on" amplifiers had several tubes that had been on for over ten years.

Keep in mind that there was no B+ present in the no-demand periods.

Make of this what you will. There was no control group, etc.

I'm sure that expansion and contraction in the on/off has to take a toll on tubes. Tower chimes and home audio amplifiers are apples and oranges.

But there was a significant longevity in the "always on" tubes.

DRBILL

[mike stehr]

Cats are meant to live outside........

[JBryan]

When not in use, my preamp and DAC are in standby mode. I power up the amps and play a CD or the network player for 1-3 hours before I start listening to music.

Incidently, I've had the DAC/transport for over 6 years and the DAC has been switched 'OFF' 3 or 4 times total. The tubes came with the DAC so I have no idea how many hours were on them before I got them or how they were used but I haven't noticed any noise or any other issues yet - KOW.

-Bryan

[sunnysal]

Turned off until it is time to listen. While small signal tubes can last a REAL long time. Tubes have a useful lifetime measured in hours of use so...I´ll save my hours for listening thank you. regards, tony

[Cal Blacksmith]

DrBill;

The flip side to your story is that my parrents ran an RV repair center. They had a Bogen tube PA amp that was turned off every night and on every day for about 15 years with no ill effects either. LUCK? Who knows, but it is true none the less.[]

[kaiser SET say]

Unless I'm gone for more than a day (as a safety precaution) my pre-amps are on 24/7, have not lost a tube in 6 years but the 6922 is one tough little booger, my 6SN7's & 6V6's seem to hold up well also[]

I have always been from the 24/7 tubes on camp and I have found as long as they are just warm and not driving they have never changed my electric bill so being on and ready is the way I have always gone.