NOS tubes

Discussion in 'Glowing Bottle Tube Amp Forum' started by golfnut, Nov 22, 2018.

  1. golfnut

    golfnut Friend of Leo's

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    I just picked up a pair of Jan Philips 6L6WGB from the tubestore. I wasn't expecting a change in tone and wasn't sure I even needed to replace the JJ tubes that were in there. However I didn't have a set of backup power tubes so I figured why not.
    After the change I found I had noticeably more volume and clean headroom. The bass seemed tighter. Overall a tone improvement. So I'm wondering if the JJ tubes that were in there may have been worn. Or there could be another reason that it sounds better. Full details:

    Amp: Allen Accomplice.
    Recommend Bias range: 30-35MA

    I decided to check the bias on the old tubes first before I took them out. After about a 20 minute warm up I found them idling at 29-30ma. I could have sworn when I biased a couple months ago that I was closer to the "Allen" recommended maximum of 35MA. Lately I've been getting a bit of an ugly tone mainly in the mids. Wondering if it was because I had this biased on the cold side.
    So then I put in the NOS tubes and biased to 34-35 MA (Just about exactly the pair were within 1MA or slightly less of each other). I let them amp warm up for 20 minutes.
    I then plugged in and noticed the improvement. So was it because the new tubes were fresh and the old ones possibly worn out or because I biased it warmer? Is 5ma warmer that much of a difference?
     
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  2. Old Tele man

    Old Tele man Friend of Leo's

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    NOS tubes were (usually) "true" MILSPEC devices, meaning they were excellent. Today's namesakes, however, are related only by their names, since current tolerances are almost ±50%.
     
  3. Milspec

    Milspec Friend of Leo's

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    I am no expert on vintage tubes, but I do have a lot of experience with "milspec" standards. To anyone who has spent time in the military, military specs means cheapest contractor. That said, I do believe that vintage tubes were of better materials. The trick is getting good ones, as they can test NOS yet be very noisey. I have not run into that problem with modern tubes so maybe it is the aging process to blame? I just know that I went through 4 NOS rated tubes to find one that was quiet on my vintage Century amplifier.

    As to the OP's question, I think the answer is that you gained improvements due to being newer (usage wise) and vintage. Not just due to wear, but because you expected to hear an improvement. There is a real placebo effect when you purchase new gear that can't be denied, which is probably why we all keep buying new stuff and keep making changes to our gear.
     
  4. Old Tele man

    Old Tele man Friend of Leo's

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    Very TRUE about the "lowest" bidders, however, Quality Control and Lot Sample Testing almost guaranteed all tubes met or exceeded specs.

    This was the era when Leo's amps could be simply biased to schematic values and power tubes replaced with almost certainty that operation was gonna be acceptable. No body tested or matched tubes back in the 1950-60's...this didn't become popular until US-manufacturers exited the market and imported tubes became common.
     
  5. golfnut

    golfnut Friend of Leo's

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    Actually, as I said in the OP I did not expect to hear any improvement whatsoever. I bought NOS power tubes in hopes of longevity. I'm thinking I probably heard an improvement due to biasing warmer. I just wanted to see if anyone may have agreed with that.
     
  6. Nickfl

    Nickfl Tele-Afflicted

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    Or, it didn't become popular until the internet allowed audiophile cork sniffing voodoo to spread to the point that it became "common knowledge". Now "everyone knows" you have to pay extra for matched tubes, even though most don't know what is matched or why
     
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  7. Old Tele man

    Old Tele man Friend of Leo's

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    VooDoo electronic VACUUM snake oil! :lol:
     
  8. jrblue

    jrblue Tele-Afflicted

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    My understanding of military grade tubes is that they were (and this is usually many decades past) often ruggedized, less microphonic, and tested -- not that they are just built to the same specs as the cheapest version of the generic tube type. I have had excellent luck with military grade preamp tubes. I agree with everyone who says that current manufacture, including reissues, are basically terrible. I'm not one to knee-jerk praise on vintage stuff -- I have vintage, used, and brand new equipment -- and there are plenty of older tubes that are disappointing, but wow -- I have a really hard time finding new production tubes that are anything but terrible, to the point that I am seriously thinking of changing over to solid state. Finding good NOS tubes without getting shafted used to be easy enough... now it's like searching for sasquatch.
     
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  9. twotone60

    twotone60 Tele-Meister

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    I know that David is rather fond of JJ power tubes - my Chihuahua shipped with one - but their QC has been questioned here many times. Perhaps you are just hearing a better quality tube producing a cleaner sound with more headroom.
     
  10. Shidoin

    Shidoin Tele-Holic Silver Supporter

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    I don’t know about tone improvement; but I do about longevity; my ‘58 Gibson GA-20T has it’s original tubes, and they just tested vert strong. Good to go for another 60 years!
     
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  11. Old Tele man

    Old Tele man Friend of Leo's

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    Same thing here with my 1969 Fender Super Reverb: still running on all of its original RCA tubes (although I do have a pair of 'original' SVETLANA's as spares).
     
  12. aerhed

    aerhed Friend of Leo's

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    Those fat WGB's are pretty good and solid. They're in my top 10 for lower plate type 6L6. The same tubes were labeled 5881, but I like the Tung Sol style with the mica snubbers better.
     
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  13. Nickfl

    Nickfl Tele-Afflicted

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    I have it on good authority that is exactly the kind of oil they use in those reproduction paper in oil caps! :D
     
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  14. slider313

    slider313 Tele-Afflicted Silver Supporter

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    I don't think that's the case but you can rule it out by installing the JJ's and biasing them at 35ma. I believe the JAN Philips tubes just sound better, and that's exactly what you're hearing. I'm not a fan of JJ tubes but have tried a few 6V6's, 6L6GC's and 7591's and old stock versions of these tubes always sound better to me.
     
  15. agogetr

    agogetr Tele-Meister

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    my brother fixes amps on the east coast. he says the new tubes are junk and the old american ones are the only way to go. just a rumour of course
     
  16. Fourstringclover

    Fourstringclover TDPRI Member

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    I also had a similar experience when I replaced all 3 of my modern high gain ruby 12ax7s with JAN 12ax7s in my tweaker 40. The once somewhat dark amp became bright and clearer, so much that I had to turn down the treble 2-3 notches. The thing about the JAN tubes is they are a cut above nos, because they were made for when people lives could actually depended on the quality. It's crazy to think these sorta things were used in airplanes, submarines, and radios calling in artillary at one time, an he we are 70 years later blasting guitars thru em.
    "Come in!!! This is Bravo team, we need air support now!! I'm glad these new Sylvanias have such great midrange for clear speech, over!" Shoot, I've read that some Soviet military tubes were rated at 10,000 hours! That's nuts!!!
    If JJ tubes are just as good, then by that logic, Chinese RI Fenders should sound just as good as 50s American made Fenders. Maybee they just charge $1000+ for all that snake oil thats been soaked into the tweed.
    The reason all industry went to China was not because their goods were just as good or better, but cheaper. It's ironic to be writing this on "black friday" no less, lol.
    No, American industry and build quality did exist at one time. It's no myth, but almost mythical at this point.
     
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  17. BobbyB

    BobbyB Tele-Afflicted

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    Im sure the NOS tubes just sound better. Having said that, a cold bias in an amp sounds like s**t. Put the old tubes back in and increase the bias see if it helps.
     
  18. mad dog

    mad dog Friend of Leo's

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    Sounds like the JJs were just getting tired. There is another possiblity. Amps can be a bit picky on tubes. I tried JJ 6L6s in a couple amps, ended up preferring the NOS 6L6WGB. But in another amp, a modded Ampeg Gemini II, those same JJs beat any other tube I tried. So it could be, even if you had a new pair of JJs to put in your Accomplice, you'd prefer the other ones anyway.
     
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  19. Axis29

    Axis29 Poster Extraordinaire Ad Free Member

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    I think there are a few terms being thrown around incorrectly in this discussion and it's getting kinda confusing.

    The OP bought NOS JAN Phillips 6l6WGB tubes, right?

    NOS means New Old Stock. Supposedly these are virgin tubes that have not seen electrons since they left the factory.
    JAN means Joint Army Navy. These are those tubes that were manufactured for the US military and had to meet a minimum testing criteria. I have had nothing but good luck with JAN tubes.
    Then, there's the 6l6WGB. These are different than the JJs in many ways. Construction and design being the #1 factors. Different plates, different getters, different coatings, and probably even different size and shape of glass envelope.

    As for the difference in sound? I'm a huge fan of Phillips tubes. I have a pile of JAN Phillips preamp tubes and a I think 3 old 6L6WGBs. I like a lot of older tubes a lot of the time. But, I will admit to running GTs and Russian 'reissue' Tung Sols in most of my amps due to cost. Although, I really do like the TS reissue 5881s a lot. I have run JJs in a lot of my amps over the years and preferred them over some brands... But, they are rarely my go-to these days. I think the thing that hooked me on older tubes was the first pair of RCA blackplate 6v6's I scored for cheap back in the day.
     
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  20. schmee

    schmee Poster Extraordinaire

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    BTW, the 6L6WGB is a lower output tube. (I think 22 watts vs 30 watts for GLC?)You may just like the sound of that better. Higher output 6L6GC's can be a bit harsh sometimes at lower volumes.
    "Military grade" just means they meet the spec someone came up with. Then makers try to see what they have that will fit the spec and the low bidder that meets the spec gets the contract. Often it's all about packaging to mil requirements more than the product. It all depends on the spec. Sometimes they are very loose and sometimes they are tight specs. many times they just refer to commercial specs. One famous fauxpax is the 5V4 rectifier tube; the 5AR4 was relabeled as 5V4 for military sales. Many years later lucky guitar players find those "5V4"'s and recognize that they are actually the much more rare 5AR4! So the military got a tube that met their spec, but not what they asked for.
     
    Last edited: Nov 23, 2018
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