Tube Replacement Suggestions

Discussion in 'Amps and Cabs [BG]' started by jerplaysbass, Apr 19, 2005.

  1. jerplaysbass


    Apr 19, 2005
    Hello All,

    It’s come time to replace the preamp tubes in my SVT 3. It uses 4 12AX7s and 1 12UA7. Has any one had experience replacing tubes? I see a lot of reviews on how they sound in guitar amps but nothing for bass pres. I'm looking for more of a fat and warm sound then something with high gain. Any suggestions?

  2. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY
    I like the JJ's from Eurotubes, and Bob is super nice and knowlegeable. The JJ12AX7S's are smooth but balanced across the tonal range...with some fat bottom. I'm running a matched balanced quad in my amp right now.

    I also like the Ei tubes...but I'm not sure how available they are...I find them lively without being brittle...but they have a high fail rate, so you'd need to buy more than you need to make sure some weren't bad out of the box. I like the ones with the longer grey plates...but I have one that's got a long/smooth/silver plate that's not terrible.

    I have a few Electro Harmonix 12AX7's around...they're supposedly the higher quality of the Sovtek lines...I didn't like this one in my bass amps...not enough on the top end...dark and not tons of definition.

    If you've got money to spend, go find NOS Mullards or RCAs...RCA Black plates are expensive, but you could find some grey plates at a reasonable price...I like these for my guitar amps more than bass...but they're good across the board. Mullards are known for pronounced mids, and are one of the reasons why those ol' brit amps sound like they did. I haven't tried em, but Groove Tubes make a Mullard replica that's been getting good reviews.

    Whatever you do, get a MATCHED set for your amp.
  3. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY
    Um... I didn't ask...what's wrong with your tubes? Most pre tubes should last a long time if not a lifetime. It's more likely power tubes that go.
  4. jerplaysbass


    Apr 19, 2005
    Thank you very much for the info. As far as my reasoning for replacing them, I've just noticed a general degerading in tone. I've tested the tube gain on preamp and the more i dial in, the crappier it sounds. It didn't use to be like that. I figured nows a good time as ever to upgrade.
  5. tombowlus

    tombowlus If it sounds good, it is good Gold Supporting Member

    Apr 3, 2003
    North central Ohio
    Editor-in-Chief, Bass Gear Magazine
    Ideally, it'd be fun to have a selection of various preamp tubes to try out. But, when you need to replace 5 tubes, that can get a bit expensive.

    What tone are you after? More full, more warm, more tight, more highs, etc.?

    I've had good luck with NOS Telefunkens and Mullards for 12AX7's, and Amperex Bugle Boys for 12AU7's, but these ain't cheap (well, the Bugle Boys aren't too bad). Of the newer production 12AX7's, I also really like JJ's, as well as the Groove Tubes Mullard reissues.

    Check out this thread for more information:

    12AX7 bass preamp tubes Favorites and Lifespan

  6. jerplaysbass


    Apr 19, 2005
    Thanks for everyone’s help. I have decided to give the JJ ECC83S. Seems like that is what a majority of bass players are recommending and they are at a great price.
    Thanks again
  7. Bongolation


    Nov 9, 2001
    No Bogus Endorsements
    It's a reasonable tube. It's relatively short-plate, which helps with longevity in high vibration applications (that's why the Sovtek 12AX7WA is the primary OEM tube - it's very short-plate and rugged).

    Don't expect to hear huge differences between preamp tubes with bass, though of course replacing a bad tube with a good one will be quite noticeable.

    If your head is well isolated from vibration, you might like a Sovtek 12AX7LPS, which is an excellent tube in a bass head, but somewhat fragile because it's a longplate (I use one as the preamp tube in my vintage Sunn head...don't tell Bob! ;) ).

    My own #1 preamp tube is the standard vintage Mullard or the Dutch Amperex "Globe," which is essentially the same tube. If you know the tube codes, you can find near-new vintage Mullards rebadged with various OEM lables (EICO, Hammond, Bogen, etc.) for about the same price as many new 12AX7s.

    The single most important part in selecting a new preamp tube is getting it from a quality reseller who extensively tests and burns-in raw stock. There is a high rejection rate in most preamp tubes as they come straight from the importers.

    Good luck!