[cooperpwc]

I did some searching and have not found a definitive answer to this:

How long does it take for a new tube to burn in and reveal its true sound signature?

I am rolling a number of tubes on my Earmax Pro. I just switched from the stock set to Electro-Harmonix driver and outputs. I have another two Russian driver tubes to try out before I graduate to some more expensive NOS tubes.

(Stock tubes should be well burned in as I used them to condition the amplifier itself. I am guessing 70 plus hours now.)

I would like to judge all the tubes along the way. Best answer I have found is that twenty hours might reveal a tube's true characteristics.

Any thoughts?

Yours with tube newb gratitude.

 

[n_maher]

My thoughts would be that there is no definitive answer and that it's completely variable. The more time that passes the less I worry about such things. I mean honestly, what if burn-in all of a sudden made something worse?

 

[atbglenn]

Quote:

Originally Posted by n_maher /img/forum/go_quote.gif My thoughts would be that there is no definitive answer and that it's completely variable. The more time that passes the less I worry about such things. I mean honestly, what if burn-in all of a sudden made something worse?

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?

 

[epaludo]

I can smell another burn-in believe thread discussion. There are hundreds on this topic ...

As for how many hours of burn-in you should apply in your tube, I'd say just let it play whenever you're listening. This way you'll feel (or not) the burn-in improvements and give more value to your precious tubes, instead of just let it burn-in all at once ...

 

[Eisenhower]

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?

Because when you remove all science and rational thinking from high fidelity audio, things don't have to make sense.

 

[n_maher]

Just to add something semi-relevant - I generally give tubes a half hour or so to warm up from cold. I have several pairs that take this long to stop physically making noise as they heat up.

 

[Skylab]

Quote:

Originally Posted by n_maher /img/forum/go_quote.gif Just to add something semi-relevant - I generally give tubes a half hour or so to warm up from cold. I have several pairs that take this long to stop physically making noise as they heat up.

THAT I think is the bigger issue. I'm not convinced that all tubes require *initial* burn in necessarily in terms of sounding better, with the one VERY clear exception that some NOS tubes absolutely require up to 30 hours to stop buzzing/humming the first time they are used. After that, it's really just an issue of daily warm-up time.

 

[malldian]

Is there an issue leaving a tube amp on all day? Also, whats the time between rolling tubes? Wait for them to cool down? Also at a meet the guys from whiplash told me to handle the tubes with a tissue when they are hot - something for people who aren't as advanced in tube rolling to know.

 

[Skylab]

I leave my tube amp(s) on all day. Fine as long as there is ventilation space. I also let amps cool down at least an hour before tube rolling. And I have a pair of white gloves for handling the tubes, no joke

 

[malldian]

I just saw your avatar and it was going with what I was listening to for about 3 seconds - very good

 

[cooperpwc]

Actually I was not assuming that burn in would make tubes sound necessarily better. I was more interested in the point at which the sound becomes stable so that I can make comparisons.

Thanks for the input all.

 

[Spareribs]

I remember reading somewhere that the president of Western Electric said around 500 hours for the WE 300B tube in a Stereophile interview. I can't find the article though but this discussion was on audiogon.

AudiogoN Forums: How Long to Burn-In Western Electric 300Bs?

 

[sunseeker888]

How about Chinese tubes? Like the ones which come shipped in the Little Dot amps? Guys, we are talking about NOS Western Electric tubes here--arguably some of the finest ever produced.... Now, I would think they would last a heck of a lot longer than new-production Chinese tubes. So, it would be normal to assume that the W.E.'S 500 hour break-in would be equivelant to a Chinese tubes' 500 hour break-in, BUT the WE would last longer in theory. So, is it worth it to purposely leave the tubes cooking if you have no plans to tube-roll?

Me and you might be technically inclined and DIY-handy with this stuff, but how about the hifi enthusiast who just buys an amp and knows nothing of how they work? (I suppose they are a rarity however, since tube can-amps are somewhat of a novelty even to hifi fans.)

 

[bergman2]

Quote:

Originally Posted by cooperpwc /img/forum/go_quote.gif Actually I was not assuming that burn in would make tubes sound necessarily better. I was more interested in the point at which the sound becomes stable so that I can make comparisons. Thanks for the input all.

in my experience, new-new tubes seem to need more of a breaking in than NOS or used (of course) tubes...generally, however, a night or so of good baking should give you the maximum amount of bake in / break in....any time after that will see incremental gains in sq if any...btw how r the tubes doing in ur emp experimentation???

 

[cooperpwc]

Quote:

Originally Posted by bergman2 /img/forum/go_quote.gif in my experience, new-new tubes seem to need more of a breaking in than NOS or used (of course) tubes...generally, however, a night or so of good baking should give you the maximum amount of bake in / break in....any time after that will see incremental gains in sq if any...btw how r the tubes doing in ur emp experimentation???

Bergman, give me another week and I may have something intelligent to say on that. So far I have only listened to the stock (TAD driver and unmarked NOS outputs) and the Electroharmonix 12AT7 and matched EH 6922 golds. I haven't gone back and forth to do a proper comparison. Both sets warm and compelling with a nice three dimensionality. Vocals just hang out there in space in front of me. Me thinks this is a good amp. The stock seem to have a wider soundstage but the EH are a bit more dynamic. Stock have had much more burn in... but maybe that doesn't matter it seems.

I will revert to the "where is the Earmax" thread and give you some thoughts once I start rolling the good tubes.

By the way, according to my communications with Tube Amp Doctor whom I bought the EMP from, I'm about the last guy who will get the EMP with the unmarked NOS outputs. In the future, all EMPs will come with a TAD tube set, i.e. selected Chinese tubes.