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replacing tubes in cheap preamps

Discussion in 'Preamps & Processing' started by spinchris, Jan 16, 2006.

  1. spinchris

    spinchris Guest

    i've been thinking about saving myself some money by replacing the stock 12AX7 tube inside my $80 preamp with a better tube. (i think i ran across the bnb tubes site in one of these forums).

    is this something slightly common? would it be worth it? would i get myself a more pleasing sound or a bad electrical shock?

    (note: i did find a similar question on an ART pre from awhile back, but any new input would be appreciated.)

    thanks in advance.
  2. TeddyG

    TeddyG Well-Known Member

    Jan 20, 2005
    Good question!

    I believe "no" would be the answer? Don't hold me to that!


    Because your 80 dollar pre and the "???$$$" speakers and the rest of the gear it's attached to(Assuming similarly "budget-minded" stuff), may not be able to allow you to discern any minor(Often incredibly so) differences - positive or negative - that may be there with a different tube? NOT SLAMMING YOUR GEAR!!!(See below)

    That said, TRY IT!!! Could Happen!? I can't, in all good conscience, recommend you run out and snag a "vintage" $100 dollar Telefunken, for your $80 pre, but, when you see a nice NOS(New Old Stock) or used RCA, or GE or Sylvania, or darned near any tube with a reasonable price($2, $10?), you may hear a difference - with luck, a difference you like..!? And, even if you don't you'll have an "extra" tube(s) - in stock..! If nothing else, you can tell your friends that you "changed-out the cheap tube that came with it for a "better whatever"? They'll nod appreciatively and knowingly - it'll be great! No kidding! We are ALL impressed by this stuff! And NONE OF US will EVER let you know that we "hear no difference" - guaranteed!!! I LOVE this business!

    BTW: You MAY void any warranty by just opening the box!? Though the manufacturer of my pre, when asked, told me to try another tube, I might like it - they did!!!???? Hard to beat the honesty! Seriously, they had NO choce but to include a new, just made, tube. They can't count on anything else - for the bucks they charged me for the device itself...

    I have 8 or 9 "extra" tubes sitting here, including an old Telefunken(I paid a literal few bucks for it, works fine, but is likely NOT "THE" old Telefunken!). Read-up on tubes! The number of "different" tubes, all with the same #, all from the same company(ies) is astounding - and - all said to have a certain "sound"??? In my 500 dollar pre, with my speakers and my ears, I can't hear the difference in any of them...... Well, one seems a bit "louder"(Shows higher level on the meters, I think?)... When I get my 3000 buck pre AND mic AND speakers, I'd darned well BETTER hear the difference! With my old ears.....? I never will... sigh...

    If you know any "ham" radio operators, ask them to let you know the next time there's a "hamfest"(Amateur radio flea market) in your area! Often MANY tubes there, most of "who knows?" quality, and priced that way! VERY LOW! Though, often you'll find an actual tube vender, many of which try to check their tubes to some degree - BUT, not often for "subtle sound differences", perse - that's an "audio person thing"... and YES, many of them "know" "audio people"! Watch what you pay!!!

    Got old relatives??? Check their attic! Or, even their living room tables..? They may have a picece of tube gear, like an old radio? If it includes a 12AX7(Or whatever you need) "change-it-out" with your "new" tube? I've got a lovely(Rather garish actually, but, ahh, "vintage") Zenith table radio, from my wife's Aunt, sitting right here looking, ahh, "pretty"(?), real wood cabinet and all, from the 60's(Has FM?), which has several tubes in it. Radio works(OK, it "hums along with the music" - it needs re-capped), and while I haven't checked, it may very-well include a 12AX7 - very common! Keep your eyes open(And your ears --- follow the "hummmmm".)......

    Teddy G.
  3. spinchris

    spinchris Guest

    thanks for the response and advice, ted. i'll definitely keep doing my research and experimenting.
  4. covenant66

    covenant66 Guest

    A real answer

  5. Cucco

    Cucco Distinguished Member

    Mar 8, 2004
    Fredericksburg, VA
    Re: A real answer

    :shock: :shock: :shock: :!:


    VacRac, Summit, Millennia, Avalon (even though I hate them), TubeTech, Manley, Groove Tubes (no, not the brick, the VIPre), SPL, and many others.

    I'll agree that many of the cheaper designs are starved plates and the tubes are there for decoration, but some (including some ART gear) are not starved. It's worth checking into.

    However, most $80 (if not all) preamps are starved plate designs, so you probably would get no benefit from changing.

  6. therecordingart

    therecordingart Well-Known Member

    Jul 28, 2004
    Re: A real answer

    Focuswrong? You're kidding right? Ok they have some good in their high end product, but in my opinion it still doesn't sit next to Neve and API.

    Tube preamps always will be popular, and I don't see why you are making it out the be that tubes are a new trend.
  7. 8th_note

    8th_note Guest

    Maybe because you've never listened to one? Geez.

    You can get a new tube to try out for $10 to $12 plus shipping - not a huge investment. I suggest you also try Tube Depot as well as BNB. I've bought tubes from both and they are equally good to deal with.

    A couple good options are the JJ/Tesla tubes and the E.I. tubes. Both have received good reviews and are inexpensive.

    I have a Presonus BlueTube and I haven't tried swapping the tube but I've wondered if it would make any difference. Common sense would indicate that there shouldn't be all that much difference in tubes with a starved plate design but you never know. I hope you try it and let us know what happened!
  8. TeddyG

    TeddyG Well-Known Member

    Jan 20, 2005
    I'm not sure - I think the answer was there, but - I'm not sure?

    Inotherwords, maybe(?), some designs USE the tube as much more of a marketing tool - right? The tube is "used", but, well-below it's potential(Or maybe not far below if tube quality is low?) - possibly/mainly so it doesn't "blow" - at least prior to the warranty expiring(Ha!). Anyway, used at "low power", it has little chance to "sound like" anything more than it's solid-state counterpart - if that?

    Some even "use" the tube at such low potential that they feel the need to put LED's behind it, so it appears to "glow". Maybe not needed for a proper tube that IS being "pushed" up closer to specs..? Actually, getting the 12AU7A, to "glow" like the 500z, in my "ham" amplifier, would require a 50 watt halogen light behind it!!! All tubes "glow" differently, not neccessarily a fault(Though harder to market, to some, even if working properly, if it don't "glow good", ey?).

  9. farside

    farside Active Member

    Sep 28, 2005
    Clients like it when things light up ...true story
  10. Kev

    Kev Well-Known Member

    Nov 13, 2001
    that's already been done
    not with 50 watt
    but with some yellow LEDs
    I won't name the manufacturer


    I'll just point to a web site where someone else does ... :D


    flip the lid and know what's inside the box,
    it's the only way.
  11. TeddyG

    TeddyG Well-Known Member

    Jan 20, 2005
    Yeah, I've read the "poop"(Literally), on this piece of "gear"... The picture is a scream... but, I don't know whether to scream with joy or sadness.....?


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