Let's talk New Production Tubes (non-NOS) --- 12AX7

Discussion in 'Audio Hardware' started by TheVinylAddict, Jul 24, 2018.

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  1. TheVinylAddict

    TheVinylAddict Look what I found Thread Starter

    Location:
    AZ
    October 22nd, 1973 the last NOS tube rolled off the assembly line.... :laugh::agree::blah:
     
  2. TheVinylAddict

    TheVinylAddict Look what I found Thread Starter

    Location:
    AZ
    That's what counts at the end of the day... we think alike there.

    But in fact finding mode :)... so just trying to find the facts, at some point someone somewhere cares!

    It's just good to know and fun to find out!
     
  3. Rolltide

    Rolltide Forum Resident

    Location:
    Vallejo, CA
    I'd say the early 80's. Stuff like the Philips JAN, Mullard-Mitchem CV series, RFT, Soviet military stuff, etc. If I had to guess by the 90's things were being built on new tooling for primarily guitar customers.
     
  4. Question about new production 12AX7's. I've got two GL-12AT7's with gold plated pins and two Mullard 12AX7's not the 4004 ones. These samples are not more than a few years old. To me and my untrained eye they look identical on the inside. The Mullards pin are steel but other than that they appear to be identical. Are they the same with different labels?
     
  5. allied333

    allied333 Audiophile

    Location:
    nowhere
    A 12AX7 is substantially different than a 12AT7.
     
  6. TheVinylAddict

    TheVinylAddict Look what I found Thread Starter

    Location:
    AZ
    Question - and I ask because I get different answers to this question from people who do it for a living - how important is it to buy matched tubes when buying new production? My phono preamp calls for three 12ax7's.... and till now I was planning on getting only matched.

    Then, after talking to a tube shop today near me, they said "we never match tubes when it's for preamps, we do for power amps, but it is not necessary for preamps." Now, realize the shop's audience / target market is guitar amps, not sure if that makes a difference. No, it wasn't Guitar Center, it was About Us | Amplified Parts , which is close to me.
     
  7. Davey

    Davey NP: Portishead ~ Portishead (1997)

    Location:
    SF Bay Area, USA
    I would think the matching between the two sections in each tube would be more important for you since each tube has a left channel and right channel in your case (I think that's the way the Tavish is designed), but new tubes are usually pretty closely matched internally. My case is a little different since my preamp has multiple paralleled sections for lower noise and distortion, and higher current drive, and so it has separate tubes for each channel (two 12AX7 tubes on each side for input, then passive RIAA, then one 12AX7 tube on each side for second gain stage, then one 6GK5 on each side for output stage, so 8 tubes in all), and matching would be more critical, especially since it also doesn't use negative feedback. Just depends on the circuit.

    So I don't really see a need for matched tubes in your case.
     
    Last edited: Jul 30, 2018
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  8. TheVinylAddict

    TheVinylAddict Look what I found Thread Starter

    Location:
    AZ
    So right after posting, I thought "why not ask the designer of my phono stage" and sent an email. Well, he emailed me back quickly, and came and saw you had responded too.

    He said: "The three input tubes should all be the same brand and type, they don't necessarily need to be matched"

    So in this case for this phono preamp, according to the designer, you nailed it! Thanks!
     
  9. Subagent

    Subagent down the rabbit hole, they argue over esoterica

    Location:
    Arlington, VA
    I think the line is drawn the very moment a particular tube goes out of production, or the company gets out of the business or just goes out of business.
     
  10. allied333

    allied333 Audiophile

    Location:
    nowhere
    Very good miniature tubes are made in the 1950s. Some nice tubes in the 1960s too. 1970 saw a general decline in manufacturing tubes, but Philips was still manufacturing tubes till around 1980-82ish. On the other hand Shuguang in China never stopped making tubes since around 1950. Russians were also making tubes continuously from around 1920.
     
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  11. TarnishedEars

    TarnishedEars Forum Resident

    Location:
    The Seattle area
    Matched tubes are rarely necessary inside of preamps. Only no-feedback designs are likely to see any benefit from matched small signal tubes.
     
  12. TarnishedEars

    TarnishedEars Forum Resident

    Location:
    The Seattle area
    Did you just makeup this date? If not, what does this date really represent? FWIW: I remember that Phillips ECG was still selling brand new tubes up until about 1986. I remember being told at the time this was when tube production was to ceased forever inside of the US. So these were not NOS tubes, but new stock tubes at the time.
     
  13. Rolltide

    Rolltide Forum Resident

    Location:
    Vallejo, CA
    Maybe the three different humorous emoji was your sign he wasn't serious?
     
  14. TarnishedEars

    TarnishedEars Forum Resident

    Location:
    The Seattle area
    If it was an attempt at humor, it fell flat for me.
     
  15. TheVinylAddict

    TheVinylAddict Look what I found Thread Starter

    Location:
    AZ
    Thanks Rolltide... was offline.
     
  16. A round, easy date for tubes being pre or post NOS is 1990. The reason I say this is the two main publications that began the tube revival started about then. Glass Audio started in 1989 and Sound Practices started in 1992. Those two magazines really started the thrust of tube audio back up to the front and the concept of searching out older tubes came from them to the wider public.
     
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  17. classicrocker

    classicrocker Life is good!

    Location:
    Worcester, MA, USA
    I don't own tube stereo equipment but do own tube guitar amps and have collected a large number of 12AX7 "NOS" and "ANOS" tubes over the years and found the old defunct Vacuum Tube Valley magazine tube rolling shootouts to be informative. You can download all 20 issues here with the 12AX7 Guitar shootouts in issue 14 and for HIFI it is issue 15. The data is almost 19 years old but an interesting read IMHO.

    Pioneering Wireless (Radio) - eMagazines

    That being said the tubes I value for my guitar amp may not be the best for HiFi and vice a versa as I have a pair of lightly used Telefunken's which sound too sterile in the V1 position in my Fender Deluxe Reverb while a pair of 1950's RCA blackplate 12AX7's sound glorious.
     
  18. kevinsinnott

    kevinsinnott Forum Coffeeologist

    Location:
    Chicago, IL USA
    I was a subscriber to Sound Practices. One of my favorites. A real indie publication.
     
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  19. I'm just curious, what brand and model is your Phono preamp?
     
  20. octavius

    octavius Forum Resident

    Location:
    Slovakia
    I´v decided finally to buy Genalex Gold Lion 12ax7 GOLD PINS for my Tube Box S2. I hope I will not regret it :) I´v already NOS German tubes RFT ECC83 it sound great when I compare it with stock tubes which comes from factory... But I would like to buy a spare tubes so I decide for Genalex Gold Lion 12ax7. I hope it will have better or same sound not worse than current RFT :)
     
  21. DrZhivago

    DrZhivago Hedonist

    Location:
    Brisbane Australia
    You should not regret it. I run GL's in my Tube Box S2. They are the best of all new production 12AX7 tubes.

    Regards
     
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  22. octavius

    octavius Forum Resident

    Location:
    Slovakia
    Thx :) When you compare it with stock tubes there is probably huge differences right? I remember when I tried to swap stock tubes I thought something happened to my system :) Then I put back RFT and system sounds great.
     
  23. allied333

    allied333 Audiophile

    Location:
    nowhere
    I was talked out of owning the Knight KN95 and never had the change to audition the tubes.
     
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  24. Ron Scubadiver

    Ron Scubadiver Forum Resident

    Location:
    Houston TX
    Eventually, there will be no more NOS tubes left, or the few remaining ones will be priced out of sight.
     
  25. Try TJ Full Music 12AX7 and they will make you change your mind. I have a pair of gold pins Gold Lion 12AX7 in my tube drawer, they're not bad but not that great as some say either.
     
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