# New tubes - Need burn in time??



## Robert1950 (Jan 21, 2006)

Put a new set of tube in my Jet City Pico Valve. A TAD 6L6, a Jan Philips 12AT7 and a Tung Sol 12AX7. Do new ( or not used ) tubes need a burn in time?


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## keeperofthegood (Apr 30, 2008)

I've never really known a tube to "improve" with use. Most(all) are pre operated for a set time at the factory to begin with so gassing is a non issue, and element distortions/microphonics should be dealt with as well. In most applications, if the tubes don't crap on you in the first 500 hours, they should do fine for the next 10,000+ hours of normal operation (preamps and the like not power tubes, those get over driven so are the ones typically being replaced).


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## Robert1950 (Jan 21, 2006)

Thanks. I really know squat about tubes.


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## keeperofthegood (Apr 30, 2008)

Haha I know only a little more than squat myself. However, there is a lot already posted on tubes here and on other forums and for alllll the tube radios and amps I have owned over the years, yea, plug em in and let em run. What makes it those first 500 hours just keep going and going (I've had 01A's in a 1925 radio, still good and strong). I have not seen any "modern" shop tours of tubes being made, but I know "back in the day" there was a burn-in run done as part of the making of them. And I know Wild Bill has many times said that any of the tubes before the finals tend to not go but those power tubes at the end are ones that are driven some pretty harshly so more often replacement is needed with them.


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## robertkoa (Jun 7, 2010)

I had a tech put a JJ803s in my Hughes and Kettner Tubeman and after I played it for awhile I was going to bring it back and try something else "cause it was a little Fuzzy sounding in overdrive modes.

Next day I was going to have him try an old RCA, but I tried it again and ALL the fuzz went away, the thing sounded better than ever super gainy and clear.

So I guess the tube needed a few hours, running at 250 volts. Guessing it should not take more than 8 or 10 hours, leave it on overnight if not a fire hazard..............and see.


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## sulphur (Jun 2, 2011)

Don't most tube retailers burn them in before they are matched? 
I'm pretty sure that the ones I bought out of Atlanta were.

http://analogtubes.com/tubeshop/index.php?main_page=page_3&zenid=605970ac42f2cd3296a88c69f6d76689

Scroll down to where it says "testing and matching our tube sets"


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## Razbo (Jul 19, 2011)

I find tubes get warmer after several hours use. I would suspect burn in periods at the manufacturer would be minimal (due to high electricity costs, etc), therefore, some burn in might remain to complete the process. I have Jet City 50h and the chinese tubes sounded warmer after some time. I replaced them all with JJ's which also warmed up after several hours of play. Maybe 15 - 20 hours in my estimation.

Could all be my imagination, though. 

p.s. I just noticed the date on the last post. I will try not to dredge up the past in the future


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## keeperofthegood (Apr 30, 2008)

Haha it is ok, this thread does resurface at times and some many years older threads than this as well. 

Though I know a little more squat than I knew a few months ago I know that I think many things. Sometimes I think "new" means "different" but a few hours later it means "much what it used to be" and probably "better than it had gotten" or "why isn't it as good as I used to think it was". BUT THEN I also think "massage" sounds good but a few hours later I'm too relaxed to feel more than awesome. Sometimes it isn't the time on the outside that makes the difference 

Yes, though what I know is limited I do know it is poor form in writing style to use the word 'but' any more than once in a article. Poor form to use single quotes on words too. It is also true that using the phrase it is also true is a good way to fail to express the desire to show your competence in a discussion and in fact tends to show the opposite. No facts are in fact of course so that is a total misnomer. Misnomer is a regularly misused word as its self suggested meaning is not it's definition (poor excuse as it is blindingly obvious to me at least). The use of its and it's is also often misused and really it is is just as easy to type as not (say those last two words ten times fast). If you feel I said misused too often I can but confess. Yes, unintended double entendre with can but confess there.


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