NOS Power Tubes

Discussion in 'Ampage Area' started by stevo, Oct 6, 2018.

  1. loudnlousy

    loudnlousy Friend of Fred

    Age:
    53
    Oct 18, 2015
    Hildesheim, Germany
    Nope. But I moved the boxes from one to another unopened.
    Actually I had not more than 4 rehearsal places in 40 years.
     
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  2. stevo

    stevo Country Gent

    May 1, 2012
    Atlanta
    For the most part, that is very true. And the high interest in JAN tubes didn't end up being a great thing as the tubes weren't always designed for audio. So they're rugged and long lasting, but don't always have the best guitar tone and can be microphonic. I have several JAN12AX7s and they go in reverb and phase inverter positions. Sound pretty good, but I like some modern ones better. But I found some old Tung Sols that have great tone, but are a bit touchy with the microphonics.
     
  3. Outlaw

    Outlaw Gretschie

    423
    Jul 13, 2011
    UK
    When buying NOS valves/tubes i always look for nice shiney looking pins, if they look dull they almost certainly tubes that have been pulled from an amp and could be near the end of there usefull life.
     
  4. chicago slim

    chicago slim Gretschie

    Age:
    65
    466
    Dec 27, 2008
    Bowling Green, KY
    I got three sets of NOS Tung Sol 5881's, about 35 years ago. They do sound fantastic, and seem to last forever. I would occasionally buy new 6L6's to replace them, but the new tubes never sounded as good. I let two sets go, when I sold vintage amps. I'm down to my last set of Tung Sol's.

    I also have a few NOS pre-amp tubes. Mostly GE 6811's, that were made for Korean war era walkie/talkies. They are made to withstand more vibration, than normal 12AX7's. But, they don't really sound much different.

    For modern tubes, I found that JJ 6V6S's, get pretty close to the Tung Sol 5881 sound. I also found a modern set of Svetlana 6L6GC's, that seems to have more of a hi-fi sound, than most modern 6L6's. Electro-Harmnix 6V6GT's and 12AT7's, have both served me well.
     
  5. stevo

    stevo Country Gent

    May 1, 2012
    Atlanta
    FYI: I just plugged in a pair of modern Tung Sols that I forgot I had and they sound very much like the old ones only a tad fatter.
     
  6. hcsterg

    hcsterg Country Gent

    Feb 13, 2012
    France
    Guys, I already wrote this somewhere in the forum, I guess (where ? :oops:)...

    What you call NOS tubes are OLD before being new, if I can say so... Being unused, still in sealed box doesn't mean they're not ageing and affected with characteristics dispersions or lowering vacuum. Where and how have they been preserved ? Some batches of NOS tubes are less lucky than others... You can both have very good, mixed and poor surprises.

    I have 2 batches of 1959 tubes, originated form French Army Signal Corp : one is JAN-6L6WGB/5881 from Tung-Sol, in perfect performance condition, the other is JAN-6L6GAY "coke bottle yellow base" type from Sylvania, and most of them have lost a bit of vacuum, some with a tendency to overheat in usual working conditions...

    That said, you probably remember that "tight and high" vacuum tubes are "harder sounding" and more powerfull than "loose or lower" vacuum tubes which compress and clips more gently. The difference is obvious between my two batches of NOS 6L6, among others.

    The vacuum condition of a tube has a great influence on his tone, and IMHO, it often explains why you find good or poor performances with NOS tubes, "brand new right out of the box", varying from one batch to another, even from one sample to another, even from the same brand or batch.

    I should take pictures of these tubes as is and under test to illustrate what I write... :rolleyes::oops:

    A+!
     
    Last edited: Oct 10, 2018
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  7. wabash slim

    wabash slim Friend of Fred

    Age:
    69
    Feb 10, 2010
    lafayette in
    You also need to consider that tube technology is 100 years old or more, and the only people using them are some audiophiles and guitarists. Tubes have been on the way out for fifty years, and we're the only ones keeping them alive.
     
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  8. stevo

    stevo Country Gent

    May 1, 2012
    Atlanta
    Yes - and it was easier to find the really good ones 20 years ago as there were treasure stores of fresh boxed NOS tubes that had never been touched and were apparently stored in good environments. But the FIT rate of these old tubes didn't get better with age, so just because it's NOS doesn't mean it's good. They will, as you alluded to, have the same failure rate as before only higher due to the age and conditions of storage.

    This being said, when you find a good power tube, you might just find a really good one and the tone can be magical. But I can honestly say that modern tubes - Tung Sol re-issues and TAD 6L6WGC specifically - sound really really good. So good that most people won't want to take the trouble to search out the better sounding NOS tubes.

    I really have to divide it between power tubes and preamp tubes though. My experience with NOS preamp tubes has been that modern ones often perform better in both tone and noise/microphonics. I have JAN Philips 12AX7s that are killer - can take the vibrations, don't have microphonics and have lasted for years. But the tone wasn't all that exciting, so I relegated them to phase inverters and other positions due to their longevity and put modern ones in V1 and V2. Every once in a while, I pull out the old Tung Sol and/or Mullard 12AX7s and plug them in and they sound great in V1 and V2. But I'm not sure anymore if they actually sound better. Certainly they're not worth what people charge for them today. But I got them back when it was worth it. And half of my Tung Sols can get microphonic with high volume.
     
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