Best approach for when to turn a valve amp on and off

I’m not sure whether it’s best to turn the amp off if say I know I’ll be listening to it again in a couple of hours. This can happen quite often. The previous SS amp would be left on all day mostly.

It seems like a cost of electricity for leaving it on vs. on/off wear-and-tear on the valves… And is it actually more damaging for the valves to be turned on/off throughout the day than to be left on?

The amp has a ‘soft start’ circuit to supposedly help extend tube life, but I’m not sure how much difference that really makes.

Is there an optimal approach?

Thanks,
Rob

 

I don't know if it's optimal, but my tube preamp goes on when I wake up and off when I go to bed.

 

I always turn mine off even for s couple of hours.
Solid state is a different beast.
I an keen to get the best out of my system, but could never the difference( i used to run Naim amplification) when leaving it on all the time. When i plugged s hi cap in i heard that!
When i plugged in an 82 pre wow! But as for leaving it on all the time. Never, its a personal thing really.
Valves are not cheap!

 

The PrimaLuna's user manual says do not let the amp run 24 hours...
If you leave it on idle for longer periods you will decrease the life time of the tubes without listening them... waste of money...
IMHO turn it on 10 min. before your listening session and turn it off when you've finished.
BTW: still happy with the PM?

 

I tend to turn on pre-amp (stand-by mode) about 1-2 hours before playing. The amps I let sit for 10-20 mins and play at very low volume for another 20 mins them slowly bring up the volume. Works for me.


sean

 

But really doe, do you tend to leave on tube amps if you think you might come back to them in an hour or so, or turn them off when you're done? I ask because IIRC you're a proponent of long warm up times.

 

What @Steve Hoffman said -- switch on tube amp/preamps; warm 'em up for 15, 20 minutes; turn off when done. Leave 'em on if you're around and listening off and on throughout the afternoon or evening or whatever, but don't leave 'em cooking unattended if you're not around, for safety's sake more than anything else. Wear and tear on the tubes? Well, you're going to have to replace the output tubes eventually anyway, the safety vs. tube life trade off is a no brainer -- too often in a couple of decades of using tube amps both at home and on gigs as a musician I've seen things go wrong: tubes fail (and maybe they just decide to start drawing too much current), resistors fail, over voltage conditions occur, etc. No reason to have a catastrophic equipment failure (or worse, a fire) as a result. Preamp tubes seem to last almost forever and I've never seen a catastrophic failure with 'em, but I still won't leave a tube preamp on unattended. Don't switch 'em on an off a ton -- like on, then off, then 20 minutes later on again, etc. But do switch 'em off if you're leaving the house or going to sleep or are going to be away from the gear of a couple of hours or something like that.

 

I've left tube amps on and unattended - nothing better than coming downstairs to see an EL34 tube plate glowing orange as it goes into runaway. Or my friend who had a vintage Heathkit W-5M power transformer go south, smoking his entire basement with tar.

My listening experience: after 20 minutes, the sound of a tube amp begins to sound great. After an hour, it stabilizes and sounds its best. YMMV

As a rule I don't even like leaving solid-state amps on all day, at least some of the ones I've owned that draw tons of current at idle which was popular for some models that run hard Class A. I might feel differently about a Class D amp. My current SS amp, a McIntosh 2100, runs fairly cool - biased heavily for Class B - and does get left on for most of the day if I'm home.

 

Turn them on when you use them and off when you don't. It's simple really. Why waste the energy?

 

The sound, man........the sound. It sounds better if you let it cook, just like simmering a new pot of chili.

 

Makes me glad I dont have a tube amp

 

Meh, if you are listening for a couple of hours, does it really matter?

 

why risk a fire?

 

Thanks for the replies. This about sums up the way I do it:

... but this is something I probably hadn't considered seriously enough!:

It is lovely coming back to a glowing, warm amp; but it's good to know it's on balance not bad practise regarding wear and tear to turn on and off between hours. Makes sense.

 

Yes re 20 ish minutes for the valve amp (can hear it improving over that time), but can't much after to be honest. The previous SS amp (Cambridge 840a v2; a kind of A/B but ran hot) sounded at it best after being left on for several hours and I generally just turned it off over night.

 

PL? Yes, loving it thanks. Was impressive enough with the stock tubes but transformed with upgraded ones (and moved to El34s). Constantly amazed at the texture and insight it provides; especially at low-mid volumes.

 

I usually turn it on and then either start playing music when the tubes are fully lit, or optimally wait a half hour. If I know I'm going to be playing music within the hour or so, I might turn it on and do something else in the meantime and then come back to it. I always switch it off when I am done. I want my tubes to last a long time!

 

Same risk as if you were playing and listening to it all day.

 

Yes and no. If you're sitting there and a tube starts red plating you can shut the amp off. Not so much if you're out at the supermarket, and if you let it run away, that's when bad things can happen.

 

Are you just being clever? Yes, the risk that a fire starts is the same, if that's what you mean. But, obviously, the risk of the fire spreading and causing damage goes way up if there is no one at home, and the risk of dying in the fire is much higher if you are asleep.

I actually have no idea if tube amps are more likely to cause a fire than other electrical appliances, such as irons, space heater, curling irons, etc. But, they sure get hot.

 

It's not so much the heat of the tubes, it's the high voltages in the amps.

If a bias control circuit fails, for example, this could result in too much current going through the tube and the tube will fail.

When tubes fail, they can take out other components, causing shorts and an electric fire.

My Rogue monoblocks are fused to protect from this happening.

This is something that is more likely with larger power tubes, not so much with preamp tubes.

Tubes do sound better if they are left on and repeated and cooling can place additional wear on tubes.

Once I light up a tube amp, it can stay on all day, unless I leave, then I turn off the amp(s).

 

Hmmm, EL34 went this morning - heard a popping/cracking noise whilst in the kitchen and came back to find the inside of the tube all aflame and smoke beginning to rise around it. Dread to think if I wasn't around. So lesson learned: take the warnings seriously folks!

 

I think there are a lot of people who BELIEVE an amp sounds better if left on all the time.

Doug