1. Win a Broadcaster or one of 3 Teles! The annual Supporting Member Giveaway is on. To enter Click Here. To see all the prizes and full details Click Here. To view the thread about the giveaway Click Here.

Question on replacing amp tubes

Discussion in 'Glowing Bottle Tube Amp Forum' started by rdec873, Feb 24, 2021.

  1. rdec873

    rdec873 NEW MEMBER!

    Age:
    47
    Posts:
    2
    Joined:
    Apr 4, 2020
    Location:
    Cary, NC
    I just upgraded my Vox AC15 tubes to Tung Sol. As I was pulling the old ones out, I noticed a couple things.
    1) The EL84’s were both China no-names which was expected.
    2) The 12AX7’s were a different story. 1 of them was a no-name brand, one was something called “Ruby” and the tube that was contained in the metal housing was a “Sovtek”.

    Here are my questions.
    1) Was it bad that there were clearly unmatched tubes in the amp, and
    2) Is it worth keeping the Sovtek as a backup in case I have an issue with one of the new ones. The others are most likely garbage

    Thanks
     
  2. MuddyWolf

    MuddyWolf Tele-Meister

    Age:
    58
    Posts:
    452
    Joined:
    May 11, 2017
    Location:
    Paradise, Ca
    Preamp tubes dont need to be matched.

    Keep all old preamp tubes as backups unless they have started to fail, like crackling cutting out or going microphonic.

    Brands buy tubes in bulk and mark their own name on them. So a mark on a tube means nothing .
     
    rdec873 and northernguitar like this.
  3. Lowerleftcoast

    Lowerleftcoast Friend of Leo's

    Posts:
    3,444
    Joined:
    Dec 30, 2019
    Location:
    california
    I am not sure if Ruby is viable anymore. They are/were a company like groovetubes and tube amp doctor. They would rebrand tubes manufactured in china and russia. They warranted the tubes for 6 months. They did not manufacture tubes.

    The 12ax7 tubes I have from ruby are JJ 12ax7. Usually the tube still had the JJ logo. They also had "special tube request" 6L6GC and EL34 made in china tubes which ime were good sounding/performing tubes.

    The only tubes in an amp that need to match are the power tubes. I very seldom have preamp tubes of the same brand in any amp. Try each of the 12ax7 in V1 to see if there is one you prefer. Sometimes you can clearly hear a difference.
     
    Last edited: Feb 24, 2021
    rdec873 and northernguitar like this.
  4. northernguitar

    northernguitar Friend of Leo's

    Posts:
    2,618
    Joined:
    Jan 18, 2009
    Location:
    North of Toronto
    Keep all the old tubes, they could have plenty of life in them! A former lead player in my cover band used to insist he change tubes every six months-all of them. Ridiculous! I scored many excellent preamp tubes. Though I couldn't use the outputs, I shoulda grabbed them too.
     
    Wally, Lowerleftcoast and rdec873 like this.
  5. Jay Jernigan

    Jay Jernigan Tele-Afflicted

    Posts:
    1,551
    Joined:
    Feb 11, 2013
    Location:
    10-uh-C
    Don't keep a tube that you know, for sure, is bad. Box and mark any "iffy" tubes. Keep the rest handy.
     
    northernguitar likes this.
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.