Found old tubes

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by jzguitar, Aug 22, 2005.

  1. jzguitar

    jzguitar Member

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    Hey everyone

    I poked around in an old 50's-era reel-to-reel tape recorder and found some tubes. One was a 12AX7 that I'm assuming is a Mullard. The code is MC1 B6H. I've included a pic of the tube, too. I'm out of town and can't try it in my amp, so I'm not sure how worn it is or if it's microphonic. Any thoughts on this tube? I'll check out the other tubes in the recorder, too.
    Thanks!

    [​IMG]
     
  2. Big White Tele

    Big White Tele Member

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    Cool, It might be a Brimar, That logo looks like BVA.
     
  3. Killa-B

    Killa-B Member

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    The "BVA" logo means British Valve Association I believe. I've seen it on both Brimar adn Mullard tube boxes.
     
  4. Big White Tele

    Big White Tele Member

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    Cool, Thanks for the info, Ive only seen it on Brimars, but Ive really never paid much attention! Its great to learn.Thanks again!!
     
  5. Jeff West

    Jeff West Member

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    Yes, that one was manufactured in Mullard plant in Blackburn, England in August '56. Will have the "bent rectangle" getter ring at the top, not halo like later '50s Blackburn Mullard longplate 12AX7s that also switch to f91 and then f92 type codes rather than mC1. Shortplate Mullards started early '59, although you can still find longplates from throughout most of that year. You can also find '56 British Mullards like this one with full Bugle Boy logos sometimes, among other brands, but the "B" factory code will always indicate Blackburn manufacture even if it says "Made In Holland" erroneously on the tube.

    I like actual Dutch-made Philips longplates from the '50s as well, and they have various mC codes right thru '59, but will have the delta or "sideways triangle" factory code (often taken for a "4") instead of "B".

    I like those mC1 Mullards in guitar amps quite well, although they're especially esteemed for audio. Sound a little bit different than '60s-'70s shortplate Mullard I61s, I62s and I63s, although same family sound. A little more extended, slightly different high end, subjectively a little less midrange punch in a plexi, say, as gross generalizations. Can still get lots of overdrive and harmonics jumping out, though. Very high build quality and longevity, in my experience. Common lore on the internet is that the 17mm plates make them "more prone to microphonics" than shortplates, but I would disagree completely and suspect that's based more on heresay than experience, at least in the case of '50s Blackburn-made. Cool tube.

    What kind of reel to reel? Ferrograph? Vortexion? Can find Mullard longplates commonly in '50s U.S. made Voice of Music and Webcor recorders, also lots of Heath and Eico gear, among others, but they're usually rebranded in the case of those particular companies.

    Jeff W.
     
  6. jzguitar

    jzguitar Member

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    Thanks for all of the info! I'm looking forward to trying this out in my amp. I think the recorder was a Revere or something like that. It was my great-aunt's and has been just sitting around for many years.
     
  7. Igneous

    Igneous Member

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    NICE FIND DUDE!!! VERY RARE B-BURN YOU GOT THERE!!!

    l-plate with square getter--Hope its still strong!!!:dude
     
  8. gilwe

    gilwe Member

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    Hi all !

    I got to this thread while searching some information about similar tubes I found. The tubes read "Torvac ECC83, Made in England, mC1 B6H".

    Found them at a very old radio repairs tech, the man is about 90 years old !! He used to service tube equipment for his entire life, and still sits in his very small dusty place every day. I was amazed to see this particular treasure, along with many other tubes, used and unused, he has. Asking him for NOS 12AX7 tubes led me to his small storage place, where he pulled out a small rotten box with places for 100 tubes !! From those 100, about 50 are still there waiting for someone to pick them up ! BUT - no cheap. 20$ each "special price" for me he said he he ;) Said he could find me some used 6L6, EL34, EL84, ECC81 etc... anything else to look for?!

    So I'm trying to figure out what brand are they actually, and how many should I pick up. Are they the same as the above metioned Mullards ? They have the rectangular top as described here. No black plates. Are these the "all sought of" Mullards many guitar players are after ??

    I tried one in my Twin Reverb amp. Sounds good, but nothing better than RCA or General Electric ... What do you say ??
     
  9. Blue Strat

    Blue Strat Member

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    Trust your ears. They're the only ones that matter;)
     
  10. gilwe

    gilwe Member

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    Yah I know, but I'm curious to know what are they actually ? Mullards ? Brimars ?
     
  11. Jeff West

    Jeff West Member

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    gilwe- By your description, definitely British made Mullard manufactured exactly 51 years ago. Not Brimar.

    Many would consider $20 per for these an extra fine bargain or better, I would say you can't go wrong. They are sought after by quite a few folks. Tend to sound a little different than later Mullards in same application, including later longplates IMO, but some would say they're inimitable. Likely to be more distinctive in Marshall or tweed than in Twin, IME. Pieces of prime British tube history no matter what else.
     
  12. DGDGBD

    DGDGBD Member

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    I picked up an old portable reel to reel a few years ago for $5 at a garage sale and found the same thing. Three mullard 12AX7's! they look the same as yours...Jackpot!
     
  13. Jeff West

    Jeff West Member

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    Yes, reel to reel recorders but also other gear. Good hunting-
     
  14. gilwe

    gilwe Member

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    Thanks Jeff !

    I think I'll make a purchase for a stock of 20 ! (how much do they sell on ebay btw ? Mike ?....)

    When else will I be able to buy those tubes in the future ? I think this is my only chance ;)

    I'm going to ask him to look for other types as well, he got many used ones.... What should I ask except for the standard 6L6, 6V6, EL34, EL84, 12AT7 ? any famous rectifiers ? anything else ?

    Not kidding but I think he is not going to live for too long, sad as this may sound... So at least these tubes are better to find themselves a good "home" !

    :D
     
  15. John Phillips

    John Phillips Member

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    I think it says that some old-production brands are over-hyped - even though they are good tubes. There is very little to no quality difference between any of the old-production US or Western European tube brands - so there is no real reason a Mullard should be worth any more than an RCA or GE. They do sound a little different, but at that point it's down to personal taste... and they all sound better than new-production tubes, to me.

    So that means that the less-hyped brands are real bargains, if you want old-production performance without paying Mullard/Telefunken prices.

    Mullards are good tubes, and I do think they sound great in British-style amps, but I also prefer GEs in my Mesas. Telefunkens I've never got the hype about at all, for guitar amps. I can see why hi-fi audio folks might like them, but that's yet another case of a something which is desirable for hi-fi being applied to guitar amplification without understanding why it's desirable for hi-fi. (Of course, if you do like the sound of a Telefunken in your guitar amp, fair enough! :))
     
  16. gilwe

    gilwe Member

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    It looks like the Telefunken and Mullards are more suitable for audio hi-fi equipment, while GE sounds exceptionally good (very sweet) on guitar amps. Much coloring (like what GE does) is not necesserily what you look for at the phono stage for example...
     
  17. KazJY

    KazJY Member

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    Jeepers, I've been trying to dump a beat up Zenith stand-up radio for $30 for awhile... I should pull the tubes, and maybe the amp out of it, and junk the rest now... good thread...!
     
  18. gilwe

    gilwe Member

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    Interesting finding. I compared a few tubes both in my Silverface Twin Reverb 135W and my TLA PA5001 mic pre. The tubes are all NOS:

    TORVAC/Mullard ECC83
    RCA 12AT7
    GE 12AT7

    Here's what I found -

    In my Twin Reverb - GE is the sweetest sounding (lot of color and mids)
    RCA is clean and warm but a little thinner than the GE.
    The Mullard was the least interesting !

    In my PA5001 -
    The Mullard was acting the best. Solid, defined, warm !
    The RCA sounded thin, the GE sounded muddy.

    So I think, like I said, those Mullards are probably much better in hi-fi equipment ! but other stuff for my Twin please.

    I looked at it again and it looks exactly like at the picture (long plate), excpet for the writing of course. I think I'll just buy the whole batch !

    ;)
     
  19. Jeff West

    Jeff West Member

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    Preference for 12AX7s other than vintage Mullards is a great thing from my POV, the more widespread the better (just don't hoard certain longplate Heerlens!)-
     
  20. gilwe

    gilwe Member

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    Guys,

    are these the ones told to be sold 150$ each ?? :confused:
     

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