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Thread: NOS tube guide

  1. #1
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    NOS tube guide

    Hi guys.

    I'm pretty new to the area of NOS tubes and I'm just wondering if anyone can recommend some good sources to learn about them. For example, a website(s) offering information about brands---like RCA, Sylvania, JAN, Mullard, etc---, characteristics---like blackplate, greyplate, black glass, etc---, and typical price ranges for such tubes. It would be nice to have a place(s) that would provide me with information that could tell me what the difference is between an RCA greyplate 6V6GT and a Sylvania blackplate 6V6GT and what a typical price would be like for each. Maybe what I'm asking for isn't really out there and I just need to keep reading. But, right now, it just seems like I can't find the information I'm looking for no matter how much I read. So any help would be great. Thanks very much.

    Justin

  2. #2
    Senior Member Old Tele man's Avatar
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    ...something to remember: near the "end" of vacuum tubes in USA in mid-1980's, most if not all USA tubes were actually made over seas and then re-labelled (also rebranded too!).

    ...so, true NOS would probably be between 1950's and 1960's when most USA-NOS tubes were actually made in USA.

    ...and, most of the MIL-SPEC NOS tubes still being sold today are from "way" back in the 1980's era!
    ...and the Devil said: "...yes, but it's a DRY heat!"

  3. #3
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    Thanks Tele man.

    So, suppose I go onto eBay and start looking for NOS tubes. If I find a set of, for example, Sylvania "NOS" tubes that are "made in USA", unless they were from the 50s or 60s, they may not actually be made in the USA but are just labeled that way. Is that correct?

  4. #4
    Supporting Member tubeswell's Avatar
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    As far as I am concerned, the late 50s was when mass tube manufacturing had reached a mass-production/quality heyday. That was when the people who designed and made tubes knew all about what to do to make great tubes, and tube manufacturers competed on quality. Alas after that, cost-cutting saw a gradual transition to cheapening shortcuts and eventual withdrawal from tube production by the big manufacturers who were convinced that transistors were the way of the future. After all, there is just more per se to making a tube than there is to making a transistor. ;-)

    There are heaps of raves about NOS tubes

    http://www.tonequest.com/articles/article3.htm

    http://www.audiotubes.com/nos.htm

    (I especially enjoy reading Brent Jessie's guff - sort of Dick Tracey meets tone-lizard.com)

    The only way to find out about NOS tubes is to dive in and start buying and trying. I have only ever tried NOS pre-amp tubes. My first purchases were GE JAN5751s made in the early 1960s, they were way better than Groove Tube rebranded (shite). Then I tried other GE tubes (triple spacer 12AT7WAs with black plates made in 1957 - the best 12AT7s I have heard), and then Phillips, Mullard, Amperex 12AX7s, which were generally nicer still, but some of which I had a few problems with, like the occasional bad triode (there are the odd duds - even amongst NOS tubes). However, based on my own humble experience I consider that NOS tubes are generally better quality, in terms of superior construction, more robust, longer lasting and less prone to microphonics, and most importantly - better sounding to my ears. How much are my ears being coloured by what I knew I spent on them? Who knows? But all the subtle psychology aside, I still think they sound better (So there).
    Building a better world (one tube amp at a time)

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    Thank you, tubeswell, for sharing your story about how you got started in NOS tubes. That's actually a big help to me in giving me an idea about how I should start out with this. I'll do as you've said and just dive in and starting buying and trying. Thanks again.

  6. #6
    Senior Member Enzo's Avatar
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    Keep on mind also that NOS simply means New Old Stock and nothing more. It says nothing about why the tube is here as a NOS item. Have they been stored nicely on a shelf for 30 years? Or did they come from someones tool box bouncing around the rear of a service van? Were they firsy quality tubes to begin with or were they seconds?

    These tubes are like any other commodity. SO the prices are all over the place. Rarity matters. And something like 7027s or 7591s might have been reeeeeeal expensive, and they they started making new ones again. There are still people willing to pay for old "real" ones, but most folks are happy to have a new stock "7027" or "7591" that plugs right into their amp and works more or less as it should. So a previously all but unobtainable tube at less than the cost of a family vacation might now be easier to come by with modern equivalents now on the market.

    And by the way, JAN was not a brand - it was short for Joint Army Navy, and referred to tubes made to mil spec. by various factories.


    And don't let mojo cloud your judgement.

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    Thank you, Enzo, for your valuable input. I'll keep what you've said in mind and let my ears be the judge. I've been using JJs in my amps and have been generally happy with them for years; so, I've never really felt a need to get the NOS stuff. However, I was bitten by the vintage amp bug a few years ago and have since been slowly learning to build my own amps so I can recreate some of those classics. I recently built a Fender Champ (5F1). And, if you're familiar with this amp, it requires a 5Y3 rectifier tube. But I can't seem to find a current production 5Y3 that is reported to work as it should in my 5F1 (eg the Sovtek is reported to cause voltages to run higher than they should). Thus, I have had to start looking into NOS tubes that are supposed to be an appropriate match for this amplifier. So, my interest in NOS tubes was born out of necessity. Anyway. Thanks again for your input.

  8. #8
    Senior Member Garydean's Avatar
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    FWIW
    Be careful when buying "NOS" tubes. Some dealers will sell NOS tube if it tests new.....the term NOS has taken on a new meaning to some dealers. I've run into sellers who claim their tubes are NOS and they have tarnished and bent pins. Yes, they test like they are new but they may have been used. I always ask first before plunking down $ on NOS.

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    On the NOS tubes, the labels/codes will tell you country of origin and sometimes the factory and week/year they were produced. The quality control on the NOS tubes was excellent. I wouldn't be afraid to buy an untested NOS tube, as long as it really was NOS. I'd be wary if they don't come with the original box that matches the tube brand.

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    Be wary too even if the tube is "tested"...it may have emissions up to par sure, but it could have a heater-cathode leak that makes it hum unbearably, or a distorted grid, or little getter left and/or lower than normal vacuum. The only good way to test an audio tube is to put it in the amp you want to use it for. What looks good on the tester and what sounds good in the amp are different things, and what looks new on the tester and what *is* new are different things!

  11. #11
    Senior Member Enzo's Avatar
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    Amen 6267.
    Education is what you're left with after you have forgotten what you have learned.

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    Senior Member TD_Madden's Avatar
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    Enzo, I like your new motto....sort of like this one:

    "Experience is what you get when you DON'T get what you want."

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