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6L6 headroom

Discussion in 'Amps and Cabs [BG]' started by seanlava, Sep 13, 2005.


  1. seanlava

    seanlava

    Apr 14, 2005
    calling all tube heads! I'm currently running a Mesa Boogie Buster Bass all tube head (200 watts) into a 2x10 cab, and I'm finding that even with my moderately loud blues band, I don't have enough usable volume. When I play any accents or solo features, the amp clips into undesirable distortion. My question is; could the distortion be caused by the power tubes I'm using? I currently have Mesa STR 430 6L6 power tubes installed. I've heard that these tubes have a relatively low breakup threshold. Would another power tube allow me to get more clean volume from this amp?
     
  2. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY

    I would guess that you could get more clean headroom out of other tubes, but I would also guess that you're coming close to using that amp to the limits of its ability, especially if you're playing with a louder blues band with only a 2x10 cab. I bet you could have luck by both switching out your tubes (my preference would be JJ's from Bob @ Eurotubes), and by using a larger cab, either a 4x10 or maybe adding a 1x12 to your current rig.
     
  3. protoz

    protoz

    Nov 30, 2000
    Iowa
    You really can't change the tube type but adding more speakers would definately help you out.

    More speaker area=more volume=less strain on the amp
     
  4. seanlava

    seanlava

    Apr 14, 2005
    really? I just assumed that since the 2x10 has more power handling than the amp puts out, that it was as loud as it was going to be, even if more speakers were added.
     
  5. cheezewiz

    cheezewiz

    Mar 27, 2002
    Ohio

    No..that's not correct. Putting 200 watts into a 410 will almost always (depending on efficiency, etc), be louder than putting 200 watts into a similar 210.
     
  6. sound volume is dependant on how much air is moved, so if you think about it, 4 speakers will move alot more air than 2 even if its a lower power rating overall
     
  7. The 0x

    The 0x

    Aug 24, 2003
    Timonium, MD
    Don't use Mesa tubes, and install bias pots on that amp ASAP.
     
  8. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY

    Not necessarily...

    I agree about not using Mesa tubes, but you don't really have to do the adjustable bias pots...A good tube dealer CAN put together a killer set of matched tubes that run well within (and probably better than the mesa ones) the parameters of your head.

    When you buy your new 'non-Mesa' tubes, make sure that you identify the type of amp you have to the seller and go from there!
     
  9. What 210 cab are you using? Some are very inefficient (eg Acme). The best have a sensitivity rating of around 103dB. But generally a compact cab needs more clean watts than the big old dinosaurs we used in the 70's. The reason I can use a little 210 is that I have plenty of clean watts to drive it. If I still had my 100w Fender or 120w Acoustic amp from '76, I'd probably still have to use those flabby 215's just to get heard.
    My sound and my back have improved a lot since I moved on to compact solid-state amps and Eden 10's. If I want vintage grind, there's pedals for that.
     
  10. seanlava

    seanlava

    Apr 14, 2005
    I'm using a cab made for me by a cab making friend, so it has no stats that can be compared with commercial models.

    thank you all for your tips. Now i'm off to get some JJ tubes, and a new 4x10...
     
  11. That may be the problem, depending on your friend's ability to match the cab with the speaker's parameters. Sure, he may be the greatest woodworker in the world...but if the speaker doesn't match the cab, it'll be inefficient or sound lousy or both.
     
  12. Matt H

    Matt H

    Jul 30, 2005
    Ithaca, NY

    hell yes-

    now, the following poster may have been correct, a tube dealer may be able to match up a pair of tubes that are in the right range...


    however- mesa has these amps biased way too cold to begin with... they do this on all of their amps, it's not bass amp specific.

    tubes biased correctly (which i fundamentally believe just isn't going to happen with a stock mesa amp, regardless of the tubes used) can make a huge difference with headroom and volume (two different things).

    Screwing with your EQ can make a huge difference too.

    also- i just want to second the "more speakers" and "more efficient" speakers comments- that's the single most important factor as far as i'm concerned.