No breakup - should I replace tube?

Discussion in 'Amps and Cabs [BG]' started by project_c, Dec 16, 2012.

  1. project_c


    May 8, 2008
    London, UK
    I have a Fender Bassman tv15 which has always been a lot more difficult to push into overdrive / breakup than it should be. I am only able to get any tube grit / breakup with active basses with the gain on full and the volume at around 4 - any less than this and there's no breakup to the signal at all.

    The amp sounds great but I love the mild grit it adds when pushed hard, and it seems like I'm having to push a bit too hard to get there - is this a sign that the tubes need replacing, or is it something else?
  2. mellowgerman

    mellowgerman Supporting Member

    Jan 23, 2008
    Orlando, FL
    A lot of times the warm gooey breakup people associate with tube amps happens at the power stage of the amplifier. Since the TV15 features a solid state power amp, you won't be able to get the signature overdrive sound that a vintage Bassman would produce. I would expect that the tube preamp is more for a warm tone (in theory) than for overdrive.
  3. project_c


    May 8, 2008
    London, UK
    thanks for the reply but check the Friedland review on youtube - he is able to push these amps to breakup without much effort.
  4. B-string

    B-string Supporting Member

    Try a new high gain preamp tube.
  5. mellowgerman

    mellowgerman Supporting Member

    Jan 23, 2008
    Orlando, FL
    hmm you're right... perhaps it would be worth while to switch out the tube. There are a lot of different choices out there... maybe someone who also owns the amp and has played around with different tubes will chime in.
    Wish I could be of more help!
  6. two fingers

    two fingers Opinionated blowhard. But not mad about it. Gold Supporting Member

    Feb 7, 2005
    Eastern NC USA
    If the tube doesn't want to break up maybe you should try to work things out. There's obviously a lot going for your relationship if the tube is trying so hard not to let you go. Of course, it could turn into a fatal attraction kind of thing and nobody wants that. Good luck. Relationships can be hard.
  7. project_c


    May 8, 2008
    London, UK
    hmm maybe I'm not driving her hard enough. :)
  8. B-string

    B-string Supporting Member

    Be sure the volume on the bass is wide open. Raise the pickups closer to the strings.
  9. project_c


    May 8, 2008
    London, UK
    Thanks for the advice, the bass I'm using has a loud output so the issue isn't that the amp isn't getting enough from the bass. I was wondering if the lack of overdrive could be a sign of a dead / dying tube?
  10. B-string

    B-string Supporting Member

    It is possible, tubes can and do go weak.
  11. SirMjac28

    SirMjac28 Patiently Waiting For The Next British Invasion

    Aug 25, 2010
    The Great Midwest
    I think you are hearing the mic clipping ? I had the dual ten worst amp I've ever heard I bought it based on that video Ed did and I returned it the same day. I think the only way you can do it is to get a tube preamp pedal like a Tube Works Blue Tube pedal they are inexpensive and really respond well to different tubes.
  12. BawanaRik


    Mar 6, 2012
    New Jersey
    Get a pedal. Not all amps are designed to be over driven. A pedal is designed to be over driven.
  13. +1 & many passive basses are louder than many active basses. My passive Telecaster bass has far higher output than any active bass I've ever used.
    But, I think that amp's really only designed for a mild overdrive, but if u can't get that, perhaps a higher gain tube-tho it's probly already got a 12ax7 in it, so you'd have to find a higher gain 12ax7 I s'pose.
    I know (Fender's) "Groove Tubes" have a numbering/colour code starting the gain "level". Maybe others, but, again, I know nuthink!
  14. hdracer


    Feb 15, 2009
    Elk River, MN.
    I would pull out the stock Groove Tube 12ax7 and drop in a good tube.
    One of my favorites that doesn't cost a fortune is the Electro-Harmonix 12AX7 Gold Pin. I have them in all my 12ax7 sockets.
  15. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Are you using the active input or something? I only played one of them once, but I remember it being pretty easy to get distortion out of it with a Precision.
  16. edfriedland


    Sep 14, 2003
    Tucson, AZ
    I was able to get overdrive from the TV 15, but I was playing an active MM bass. It might be tougher with a passive instrument.
  17. project_c


    May 8, 2008
    London, UK
    Nope - that's definitely the amp breaking up, not the mic. And in terms of tone, I searched for a long time for an amp I liked, and to my ears, these things sound excellent, so the problem is not that I dislike the amp at all. I actually love it a lot.

    No, using the correct input (input 1) for tube grit, and I do also have a Precision which has a very loud output, and I'm unable to get anything like distortion from it with this amp.

    Yeah, I get what you're saying, but this amp is in fact designed just for that gentle and mild tube drive, it's one of the reasons I got it.

    Thanks for chiming in, Ed - actually, in the section before that, the gentle tube distortion you get with the passive Jazz, gain all the way up, is something I am unable to get even with an active Jazz ('11 USA deluxe), unless I also have the volume almost maxed out on the amp too. That's why I was wondering about this.

    Thanks for this suggestion - it can't hurt to try it, at least. I have a suspicion that I might have a weak / dying tube, and that's what is behind this. I can push this amp into gentle overdive, but it has to be almost maxed out on both gain and volume to get there, even with active basses, and I just think it shouldn't be this difficult.

Share This Page