[Uncle Erik]

Tubes have many different operating points. A 6SN7 in one amp can be operated differently in another circuit. If break in happens, the period would depend on the amp.

I don't leave tube gear on 24/7, either. You have to give your equipment time to cool off. Every component has a lifespan and heat is the number one enemy. If parts never get a chance to cool dow, their lifespan is a lot shorter.

 

[883dave]

To me it is more about burn-out rather than burn-in.

The first time you energize a tube it starts to decay.

In my system tubes sound the best when warmed up for at least 15 minutes

 

[Skylab]

Quote:

Originally Posted by sunseeker888 /img/forum/go_quote.gif How about Chinese tubes? Like the ones which come shipped in the Little Dot amps?

Those take no time at all to burn in - they go right in the trash can

 

[fordgtlover]

Quote:

Originally Posted by atbglenn /img/forum/go_quote.gif My thoughts exactly. Why is it that burn-in always seem to make things sound better. That never made sense to me. Why can't it go the other way and sound worse?

I've been asking that for quite a while here, and of course, had it pretty much ignored each time. Maybe it's just me. or there is no logical answer?

On topic, I have read and heard all sorts of times indicated for tubes to burn in, but I tend to just turn the amp on and listen. I tend not to want to sit around and wait for the magic to appear. I'd rather just listen to music.

I can't think that my musical memory is good enough to figure if my tubes sound better than last week, or even yesterday.

 

[Eisenhower]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif Fine as long as there is ventilation space.

not really because tubes have a finite lifespan and by leaving them on all day you're just burning up the filament/cathode.
also tubes loose vacuum over time. If anything a tube sounds best right out of the box, as the manufacturer intended,

Do any of you actually know how tubes work?

 

[atbglenn]

Quote:

Originally Posted by fordgtlover /img/forum/go_quote.gif I can't think that my musical memory is good enough to figure if my tubes sound better than last week, or even yesterday.

X2 here

 

[Skylab]

Quote:

Originally Posted by Eisenhower /img/forum/go_quote.gif not really because tubes have a finite lifespan and by leaving them on all day you're just burning up the filament/cathode. also tubes loose vacuum over time. If anything a tube sounds best right out of the box, as the manufacturer intended, Do any of you actually know how tubes work?

There is no need to be so rude in your post.

Yes, we know how tubes work, and turning tubes on and off repeatedly is far more likely to lead to premature death than turning them on in the morning on a day you plan to listen, and then turning off at the end of the day.

 

[jamato8]

Quote:

Originally Posted by atbglenn /img/forum/go_quote.gif My thoughts exactly. Why is it that burn-in always seem to make things sound better. That never made sense to me. Why can't it go the other way and sound worse?

It does sometimes. I have heard this with tubes. I have had tubes that just wowed me and as they settled after 20 hours or so all the magic was gone and they went flat. You never know.

 

[Eisenhower]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif There is no need to be so rude in your post. Yes, we know how tubes work, and turning tubes on and off repeatedly is far more likely to lead to premature death than turning them on in the morning on a day you plan to listen, and then turning off at the end of the day.

No, that is 100% speculation. Light bulbs don't work like that, and neither do tubes.

 

[manofmathematics]

Funny. I've never lost a tube leaving it on all day, or even weeks at a time. I have, however, lost a couple during power on before.

Not really speculation, just experience.

Heck, come to think of it, the majority of my light bulbs seem to go when turning the light on too.

Now, I wonder why that is?

But what do I know?

 

[atbglenn]

Quote:

Originally Posted by Eisenhower /img/forum/go_quote.gif No, that is 100% speculation. Light bulbs don't work like that, and neither do tubes.

I have to disagree. 9 times out of 10, a light bulb will burn out when powered up. When a tube is cold and power is applied, the internal parts expand due to the heat rise. That has to be stressful and probably is a factor on tube life. I think it would be better to leave a tube amp on for the day instead of turning on and off several times. The heating and cooling can't be all that good. Just my 2 cents

 

[Penchum]

Quote:

Originally Posted by Eisenhower /img/forum/go_quote.gif not really because tubes have a finite lifespan and by leaving them on all day you're just burning up the filament/cathode. also tubes loose vacuum over time. If anything a tube sounds best right out of the box, as the manufacturer intended, Do any of you actually know how tubes work?

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif There is no need to be so rude in your post. Yes, we know how tubes work, and turning tubes on and off repeatedly is far more likely to lead to premature death than turning them on in the morning on a day you plan to listen, and then turning off at the end of the day.

X2 Skylab!

I'm a big fan of NOS tubes and try to purchase NOS tubes for all of my headphone amps. Heck, I have some WWII Sylvania 5654's, dated Sept 1943, that sound great! (They do tinkle a bit)

In my experience with NOS tubes, the majority of them change for the better SQ wise, and settle down to a stable quality in less than 45 hours. Some shorter, some longer. So far, none of mine have sound their best straight out of the box.

Newly manufactured tubes might take far less time, but I can't confirm this. The only new ones I've had came with my MKII and they were Chinese tubes, so they went "clunk" into the trash can.

Used tubes should sound the best right out of the box. They have already been used enough to be "stable". The trick is always, "how much life do they have left in them". For those of us without a decent tube tester, it's a crap shoot, so I don't buy used tubes any more.

 

[Uncle Erik]

Light bulbs get AC right off the house line. Tube filaments are usually fed off a 6.3V or 12.6V transformer and power supply. Depending on your amp, you might have a soft start from a special circuit or a slow startup thanks to tube rectifiers. You might also have a DC supply for your tubes, too, and sometimes the supplies are regulated. Turning on a tube amp isn't the same as turning on a light bulb.

The other factor is the effect of heat on the capacitors, resistors and transformers. They are only rated for so many hours and will eventually burn out, too. If they don't get a chance to cool off, their lives will be shortened.

Also consider that if a cap, resistor or transformer fails, you stand a good chance of losing some tubes in the process.

 

[Ragonix]

Does anybody ever see a blue spark inside a tube when you turn on your amp? What could this mean?

 

[bergman2]

this condition is endemic to certain makes of tubes and is fine so long as it isnt also associated with pops, noise, etc.---then it would be evidence of tube failure