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Breakup Point on Tube Amps

Discussion in 'Amps and Cabs [BG]' started by chaosMK, Sep 23, 2005.


  1. chaosMK

    chaosMK

    May 26, 2005
    Albuquerque, NM
    Hi-fi into an old tube amp
    I am trying to troubleshoot some fuzz coming out of my Mesa Bass 400. I am kind of new to tube amps and tube distortion.

    Basically I am at 7-8 preamp, 7-8 master and get fuzz on low notes. If I turn up the volume more, I get fuzz on more notes. Using a Mesa Powerhouse 4x10 cabinet, with an active bass (plugged into the channel suited for active basses).

    Is this about the normal breakup point for tube amps? Does the breakup point occur earlier if the tubes are going?

    If this is because I am driving the amp to the breakup point, how can I reduce this problem and still have high/clear output?
     
  2. Sounds about right to me. Depending on the amp of course anything past about 5 or 6 on the volume knob and things start getting gritty.
     
  3. thedoctor

    thedoctor

    Jun 20, 2005
    Try a fresh battery set in your axe. My EMGs get REAL cranky below about 7 volts. Someone needs to shoot that rabbit!
     
  4. chaosMK

    chaosMK

    May 26, 2005
    Albuquerque, NM
    Hi-fi into an old tube amp
    The battery is about a month old (and lasts about 6 months- year on my bass) and fuzz issues dont appear to be connected to the basses EQs.
     
  5. Fealach

    Fealach Guest

    Apr 23, 2003
    Gone to a better place
    I don't have experience with that particular amp, BUT...

    I know someone who had a 400, and remember him describing it as a big huge fuzz machine. It's been said part of the reason behind all the extra tubes in the 400+ was to get a cleaner sound at higher volumes. In the 400+ manual it states that the master should never go above 5 in normal use. Doesn't sound like a problem with the amp, different tubes might help, or might not.
     
  6. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    I hope you don't have the stock tubes in there... I hate the stock tubes, and have JJs in mine which give fuller tone and a lot more clean headroom than the stock ones did when I first tried the amp. That said, a while back I started getting fuzz again, and lo and behold after extensive screwing with the amp it was the battery in my bass.
     
  7. popinfresh

    popinfresh

    Dec 23, 2004
    Melbourne, Aus
    Replace the stock tubes if you have them in (or Mesa branded tubes at least).

    That's extremely loud for any situation to have your amp up to those settings. Are you sure the tubes arn't old or on their way out?

    Fealach - He says he has the 400, not 400+. So he'd only be using the six power tubes. Not 12 6l6's like the 400+ :)

    Also, threadstarter, what are your EQ settings?
     
  8. Fealach

    Fealach Guest

    Apr 23, 2003
    Gone to a better place
    Exactly. I never said any different.


    Some might infer something if a cleaner amp, with perhaps more headroom from the increased tubes, was not designed to be turned up past 5, there could be a connection to a similar, but not clean, amp with half the tubes when turned up well past 5. What that might be I have no idea. :rolleyes:
     
  9. popinfresh

    popinfresh

    Dec 23, 2004
    Melbourne, Aus
    Agh, reread your post and read it wrong first time through. Sorry bout that :)
     
  10. Masher88

    Masher88 Believe in absurdities and you commit atrocities

    May 7, 2005
    Cleveland, OH
    7-8 on the gain knob is pretty gritty for the Mesa 400+. And turning the master up to 7-8 while the gain is up that high...is just plain loud! It's going to be loud and fuzzy sounding...that's just how it is at those settings. The Mesa 400+ is considered a pretty clean sounding tube amp by most people. I haven't tried out a Mesa 400, though so, it may be a different animal altogether. I'm not sure what you are expecting, but almost all tube amps at those gain settings are going to start fuzzing out around there. Alot of people like this overdrive sound...but some don't and prefer it really loud and really clean...but they don't buy tube amps! ;)
     
  11. BINGO! We have a winner Johnny.
     
  12. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    Oh, the the origional 400! You need to get some 6550s in there if you need more clean headroom!