Warming up a tube amp?

BoneDigger · #1 01-23-2022, 04:51 PM

How long do you guys usually leave a tube amp on for before playing? Also, does it vary by brand?

E-OM · #2 01-23-2022, 07:18 PM

I usually give it a few minutes and then start playing quietly for 5-10 minutes... would not go high output until then.

Steve DeRosa · #3 01-23-2022, 07:41 PM

At least 5-10 minutes, longer if circumstances permit...

BoneDigger · #4 01-24-2022, 09:16 AM

Thanks guys! Was reading online and it said 30 minutes to an hours. Who the heck had that much time to wait around?

rmp · #5 01-24-2022, 09:28 AM

Quote:

Originally Posted by BoneDigger

Thanks guys! Was reading online and it said 30 minutes to an hours. Who the heck had that much time to wait around?

yikes.

I think 5 minutes is a bit on the "long" side, but it's probably a good practice.
I usually give it at least 2/3 minutes

KevWind · #6 01-24-2022, 09:38 AM

If you google this topic you will get different answers
But somewhere in the 10-30 minutes seems to be the most common answer..

One fairly concise article stated something like ::
While it will only take 3 to 10 seconds for a tube to pass a signal (depending on condition of the tube) It can take 10 to 30 minutes for the tubes to fully warm up (again depending on the tubes) and while there is no harm in playing as soon as the tube will pass a signal ,,,the sound can be different prior to that full warm up, and after that.

J Patrick · #7 01-24-2022, 10:35 AM

…..if I’m playing at home I turn it on and play….sure it sounds better after a bit but it sounds just fine right away….at a gig I like about 15 minutes before we start playing…not always an option though….

Glennwillow · #8 01-24-2022, 10:54 AM

I have a Fender Blues DeVille 410 and I typically let it warm up 3-5 minutes before I start using it. I have never noticed much difference between 3 minutes and 30 minutes, but maybe my amp is not high class enough for the difference to show up.

- Glenn

Paleolith54 · #9 01-24-2022, 12:48 PM

Quote:

Originally Posted by BoneDigger

How long do you guys usually leave a tube amp on for before playing? Also, does it vary by brand?

The manual for my Mesa TC-50 says "...at least 30 seconds, preferably longer."

At home at low power, I probably let it warm up for a couple of minutes. On a gig, I probably let it go for 5 or so then take it up to gig volume. Sometimes, at a gig, I think I perceive a difference on how it sounds after 30 minutes or so of playing but that's just as likely to be my perception as it is to be reality.

So there might or might not be something to the idea that you get optimum results after longer warmup periods, but the notion that you have to let a tube amp warm up for long periods before playing it is nonsense.

jseth · #10 01-24-2022, 01:20 PM

I have a mid-70's Deluxe Reverb... I usually turn it on standby for 10-30 minutes before I play through it... I'd do the same for a gig, erring on the longer time figure.

I grew up in Orange County, Ca., in the 50's and 60's... Fender amps are part of my Musical DNA... even way back then, players taught me to let those tubes warm up for a good while before playing...

Now, my Yamaha GL-100-112 is a different story; just plug in and play! One of the beauties of solid state, I guess...

jonfields45 · #11 01-24-2022, 01:54 PM

As an EE who never studied or designed anything tube, warming up beyond passing a signal does not make sense to me. Just my thoughts...

However, my Tonemaster Deluxe Reverb takes 9 seconds to boot!

Rudy4 · #12 01-24-2022, 05:24 PM

Hot cathode vacuum tubes, the type associated with guitar amps, require the temperature to come up to several hundred degrees F to facilitate "thermionic emission" which is at the core of the basic process of amplification.

In many of the old texts that discuss vacuum tube amplification it's not uncommon to read that the cathode literally "boils off" electrons, so that might tip us off to the high temperature requirement as part of the process.

It stands to reason that warming all the parts of a vacuum tube to those temperatures is going to take a few minutes, so I'd say use your amp as soon as it's capable of passing output to the speaker, but things probably improve after a bit more warm up time. How much? Maybe enough to notice, maybe not.

Jeff Scott · #13 01-24-2022, 05:38 PM

Quote:

Originally Posted by jonfields45

As an EE who never studied or designed anything tube, warming up beyond passing a signal does not make sense to me.

This. This. This.

Glennwillow · #14 01-24-2022, 07:41 PM

Quote:

Originally Posted by Rudy4

Hot cathode vacuum tubes, the type associated with guitar amps, require the temperature to come up to several hundred degrees F to facilitate "thermionic emission" which is at the core of the basic process of amplification.

In many of the old texts that discuss vacuum tube amplification it's not uncommon to read that the cathode literally "boils off" electrons, so that might tip us off to the high temperature requirement as part of the process.

It stands to reason that warming all the parts of a vacuum tube to those temperatures is going to take a few minutes, so I'd say use your amp as soon as it's capable of passing output to the speaker, but things probably improve after a bit more warm up time. How much? Maybe enough to notice, maybe not.

Very interesting comments... Thanks Rudy.

- Glenn

clintj · #15 01-28-2022, 05:55 AM

Once it passes signal, you can play. Generally it takes 15 to 30 seconds for all the tubes to reach full temperature and start flowing current. Letting it sit for several minutes does nothing but waste usable tube life and electricity.

Old amps chock full of carbon comp resistors did take a few minutes for everything to fully reach operating temperature so all the component values would stabilize, but there's no reason you can't play the amp while it does that. Modern components are more stable.