I thought the same thing.  But, he might have purchases used tubes.  Also, tubes don't always last as long as they're rated to live.
 
6080s are rated to last about 5000 hours.  If left on 24x7, they should wear out in about 209 days.  That's not a very long life even assuming they didn't prematurely wear out before 5000 hours.
 
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xcalibur255 said:

You wore a pair of 6080 out already john?  You must leave your amp on most of the time.

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Found this via google images

http://i80.photobucket.com/albums/j190/mikeymad/First_Shots_2008-01-26_0005.jpg
It was sourced from the comments found here. http://www.stereophile.com/content/woo-audio-wa2-1
 
So I ask, is there anything in the 6AS7 / 6080 family that exhibits a similar appearance? Long exposure or not, It's very sexy. 
I'm still running stock since I got my WA2 in Dec of 2011, but I'm putting feelers out there on the tube rolling front due to heavy use. (It serves as the main sound output on my PC...so it's getting a lot of idle  time. (I turn it off when leaving the house though)

I have tried a few pairs of RCA 6AS7G and re branded RCA 6AS7G black and grey plates, military and commercial, and I don't have any hum issues with my two SP's which are both OTL I believe.
I don't think some of my tubes are particularly excellent examples so it has to be related to the amp design.
 

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rosgr63 said:

I have tried a few pairs of RCA 6AS7G and re branded RCA 6AS7G black and grey plates, military and commercial, and I don't have any hum issues with my two SP's which are both OTL I believe.
I don't think some of my tubes are particularly excellent examples so it has to be related to the amp design.
 

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Amp design or not. Some tubes hum and some tubes don't, that's just how it is. Some tubes stop humming after a while, others never do. It's like a surprise when you buy them

 
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rosgr63 said:

I have tried a few pairs of RCA 6AS7G and re branded RCA 6AS7G black and grey plates, military and commercial, and I don't have any hum issues with my two SP's which are both OTL I believe.
I don't think some of my tubes are particularly excellent examples so it has to be related to the amp design.
 

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Allot of times some of these tubes have some heater to cathode leakage this can be somewhat reduced if the heater circuit
is run positive in respect to the cathode. With a AC ground through a capacitor I have done this in the last two amps I built
not sure if it it helped but can't heart.
  The 6AS7 was never intended to be used as a audio amp it was made to be a voltage regulator in a series pass circuit.

 
 

Tubes do not wear out they fade away instead. Yes the tubes were partly used Tung-sol 6080 and one of my Bendix 6080 is very weak now but I think that the Bendix tube has a manufacture defect that limited its lifespan. It all depends on the circuit and type of headphones like my othos which likes power.
 
I just finished rebuilding my Sencore TC28 tube tester, repaired its ultra sensitive leakage circuit and did a full factory calibration with a just a bit more sensitivity for my needs. I thought that the TS 6080 was needing a bit more volume and the Bendix was diffing out of balance and the Sencore really shows the reaming life almost nothing down to 20 microamps. Fresh tubes reads about 680 microamps on this tester. The Sencore large meter really gives wide swings between fresh and weak tubes which I like in a tester. The Sencore meter even jumps on my noisy RCA 6AS7 tubes when they ping during warm-up. I am planning to create a graph show the remaining tube life in one month steps or longer.  I have brought a GEC 6080 for $30 tube that was very clean and test at 790 micoamps steady on the tester, the highest I measured to date and I need one more in order to have a pair for the amp.
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hodgjy said:

I thought the same thing.  But, he might have purchases used tubes.  Also, tubes don't always last as long as they're rated to live.
 
6080s are rated to last about 5000 hours.  If left on 24x7, they should wear out in about 209 days.  That's not a very long life even assuming they didn't prematurely wear out before 5000 hours.
 


 

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Buying singles and matching yourself is probably the way to go to save money if you own a tester, especially if the tubes are normally sought out in pairs because of how they are used.

yes what you said is true, but the key reason I got this tester was to have a good shorts and leakage test. There are tubes that may test okay on a Hickok for example but will fail in my amp and can damaged the headphone as it happen to me once. Having a tester that has greater [size=medium]capacity [/size]to point out those troublesome tubes and preserve my investment is what drove me to get a tester in the first place. Having a tester that can confirm if the tubes are starting to get a bit weaker so that I can graph it is icing on the cake. 

John the scale on the TC28 is not for tubes and is not meant to be used for evaluating them.
All you need are the colored scales.
When you carry out the life test make sure it lasts for 60 seconds.

Anyone out there know the company that manufactured Hytron branded 6as7g tubes?

I have no reason to believe that it wasn't Hytron itself.

the ones that I see are CBS/Hytron tubes with the manufacture code of 210. Is there a three letter/number code on the tube?

I was speaking to a guy at ABC vacuum tubes who told me that these would not have been made by Hytron - I don't know anything about these except that they sound great.
Where would I find the code?

Look on the base of the tube for a three digit code. That's the EIA code. 210 is Hytron.

I have some Hytron 6AS7Gs. They don't look exactly like RCA or Sylvania or Tung Sol, who were the major makers of 6AS7Gs. So I believe they are Hytron. They carry the Hytron code.