I am getting some new tubes for my amp, and I want to do a 24-hour burn in. How?

Sophia tubes, and forget all this...

I never leave tube amps on unattended, preamps and other tubed equipment may be ok, never tube amp. My two 845 SET amp owner's manuals specifically state amps should not be played more than eight hours continuously. Push pulls and lower powered SET don't generally have this limitation.
Still, I never leave any tube amp unattended;  if a power tube red plates  you're going to have a nice repair bill.
I always just listen through burn in with tube amps, can be at background volumes and my attention on other things, but I'm always in room.

450 degrees for three hours.  Bast every thirty minutes.

If you are buying from a quality tube dealer they already “burned” them in before they tested them. You should be good to go. I know with my tube preamp I like to turn on for one hour before listening or if I just start listening I know after an hour they hit their sweet spot. Bottom line enjoy the music!

The queen has someone to break in her shoes for her..

On, no signal needed, 60 hrs, burn-in is done.

I bought tubes from Brent Jesse. 

Did NOT like them. 

He said, ok, finish burning them in, then keep or return them. Top line were his instructions which I followed.

They did change slightly, I still did not like them. I picked another I knew I liked (I had used spares of them), half the price, full refund (I paid return shipping)

Sounded great brand new and GREATER after 40-60 hrs. 

Agree with mapman- why waste tube life- you don't put your car on rollers to bed the tyres in, you just take it easy for a while or end up in a hedge.

Keep a diary of hours and perceived sound if you're that anal unless it's the istant gratification of a bedded in system you're after.

Burn in??????!

Tubes sound and perform best during their first 100 hours. Their very best the first 50 hours. They continually degrade after that.

Wire doesn't need "break-in" either! 

Only mechanical things need a "break-in" period! Tubes and transistors - no! Tubes will of course suffer from "aging" as cathode emissions decline with use - noise increases!

I like to hear the changes. Part of the fun. Part of the experience.

Replacing the stock tubes on my preamp it took 15 hours of PLAYING time to start hearing the upgrade. Keeping the preamp on 24/7 without playing anything showed no improvements.

Playing a signal through the tube for twenty minutes will do a lot more than running it idle for 24 hours. Just turn on the amp and play music.

@hilde45 thanks man. Yeah, there are a lot of people saying different things. Thanks for clearing it up though.

so you suggest I leave it on standby for about 24 hrs?

OP, gotcha. It does change the sound, and (again) it's interesting to hear the changes.

I'm amazed at how many people are telling you to just plug it in -- as if there are not a million threads about tweaks, techniques, etc. You're asking a reasonable question that many have asked before (in one form or another) and you're getting your head patted as if you were over-worrying. This is a hobby and we're on a hobbyists' forum and you're asking a hobbyists' question. 

@gakerty thanks!

For new/NOS tubes, transducers (cartridge, speakers), new amp...etc. I’ve always just listened to music and not sweat the burn in. If a piece is defective or you just don’t like its sound in the context of your system, you’ll know if from the onset and burn in won’t help much, or at all.  Music is more enjoyable versus pink noise or test tracks.

@petg60 yeah. Thanks!

Even so, no big deal, generally harshness would vanish somehow quickly and bass will get tighter. You can have the pleasure of knowing how a particular tube will sound in its lifetime.

@hilde45 

I just did some reading on other forums that it gets rid of the harshness of brand new tubes.

"...1. Connect amp to speakers...2. Plug amp in...3. Turn amp on...There is more? Really???!

Check bias if required. 

You hit the switch that says "Power", pick out some music and enjoy.

I typically go through an upgrade cycle, upgrading most components. Breakin quickly becomes a problem... tubes need a dozen or so hours to get rid of that crisp sound, but good new components require 400-600 hours to sound right. If you buy a new component and want to audition another one... you need the first broken in. If you upgrade five or six components, then interconnects... it is a mess. Most of my equipment sounds good... but not magical until after 150 - 200 hours. I have invested for magic, not just good. I’ve learned about break in for decades... I want to get through it as fast as possible. Life is too short. My last upgrade cycle took over six months, That was fast... because of break in. For various reasons I had to break in three new identical tube amps... I can write a thesis on the sound changes of a breaking in Audio Research Reference 160s. Audio Research puts time on the tubes prior to sale, so there is no obvious “new tube” break in... it is all component break in.

LOL Go ahead MC tell um when you had your first tube fire, go ahead tell um.. Everyone thinks it's funny until you go threw a few..

It is nice when someone one else does it for you. :-)

I was having 1 in 10 red plate or just not work. They were great valves but you really had to check them. 6V6 from the USSR surplus. 1.50 per valve I picked up 300 close to 30 failed. Great valves.. My Multi Miser was getting a work out.. 

Just so you know, if there is going to be a failure it is usually within 2 minutes of a new valve OR a cold start. They will put quite a light show on in a dim room.. 

OP, just wondering why you want to burn in for 24 hours? What makes you want to do that? Obviously, it's not strictly necessary to do this, and it's ever so easy for people to tell you that, but I'm more interested in what you read or what you're investigating that makes you ask the question.

Agree with MillerC

1. Connect amp to speakers.  
2. Plug amp in.   
3. Turn amp on.   

There is more? Really???!

OP the 24 hour break in is actually a burn in. One of the few times "Burn in" actually applies. The RIGHT way to "CHECK" new valves is to BURN them in for 24 hours.  So when you see the "Burn In 24 hours" they actually are or they were suppose to have been.

They set up grids and let them percolate for 24 hours. Normally keeping an eye on drift and then they write down the numbers and match for sets.

It was for failure that is the only reason for "BURN IN". If there is no failure then they go in a a unit and  "BRAKE IN" the rest of the way.  The truth of it is usually by 24 hours or so, how that valve is going to act and sound is pretty close. They don't change sonically very much after that..

SO from a "seeing if they are going to fail" perspective it is important to leave them on for 24 hours STRAIGHT..  

From a break in perspective it is just about TIME, your doing two different things...

I say plug and play...  AND KEEP and eye out for the first couple of hours.. Vary the volume a bit. Shut down and push the valves into the sockets.  I do it every now and then.. Nice firm valve seating, and wipe them off. 

Regards

Why waste tube life during "burn in"? When is that over? Who even knows? How bad can it sound? Just play it and listen. If you must leave it on when not listening so be it. Hifi is supposed to be for enjoyment so enjoy it to the max always. You don’t need advice from strangers to do that.  It's always a good idea to have spare tubes around because you can never know for sure when a tube will go or start to develop issues that might be heard.

+1 @melvinjames 

One of the interesting things about this hobby for me is trying to pay attention to different stages of break-in.

People who I know who have been in this hobby for a long time will talk about the various changes that tubes and cables can go through before they reach a level of maturity.

I think that kind of self education and how things sound is a wonderful part of the hobby and it serves well for down the road because one becomes more sophisticated about what they're hearing and what perhaps is causing it.

Burning in while listening also adds to your experience. The process can be quite subtle, very obvious, or something in between and you gain more understanding hearing the changes.

@rodman99999 @hilde45 

thanks guys. They are to come in on friday.

Ill probably go with @petg60 

I would rather go on "or you can just enjoy the tubes for several hours each evening".

Here are just a few sentences (verbatim), from a letter that Brent Jesse includes, when you receive tubes purchased from him:  "New tubes need a break-in period before they can exhibit their true sonic character when used in audio circuits.       Preamp tubes especially benefit from a good break-in.       This period may vary widely, but NOS vintage tubes usually need at least 48 hours of use, sometimes up to 100 hours.       New current production tubes need 24-48 hours typically.       Good break-in can be accomplished by either leaving your tube unit turned on for 2 days in a no signal condition, or you can just enjoy the tubes for several hours each evening and they will be broken in after several weeks."         An opinion from another highly regarded (personally, at least) source, on power tube burn-in: https://tctubes.com/power-tube-testing.aspx        Upscale burns theirs in for 72 hours, before testing:  https://upscaleaudio.com/pages/test-equipment       interesting:     https://www.youtube.com/watch?reload=9&v=jwmDf5bSRMQ

The way I've done burn in is to put on a track of pink noise and put on repeat, medium volume. I didn't go for 24 hours straight. I just kept a list -- day, number of hours, etc. Then each day, or overnight, I would put them on for, say 8 or more hours. Adds up quickly. My amp does not have a "standby" but I think the point is that it should be playing something, at a modest volume, through speakers.