Mesa .22 Studio + bias question

Discussion in 'Amps and Cabs' started by art_z, May 29, 2008.

  1. art_z

    art_z Silver Supporting Member

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    Is this amp cathode biased? I want to replace the EL84 tubes (they look to be original .. gasp!) with some nice JJs but am curious if I need to take it to a tech to get biased or is it cathode biased where I just pop them in and go.

    tried a search but couldn't find anything.
     
  2. pcutt

    pcutt Member

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    I used to have one and didn't do any biasing, just popped in new ones. I did this because the manual seemed to indicate that no special effort was required other than a simple swap. Check out the manual; you can find it online.
     
  3. mike80

    mike80 Member

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    Mesas are plug and play amps that never need biasing. Just swap tubes and go.
     
  4. kludge

    kludge The droid you're looking for

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    They also expect you to buy MESA-branded tubes only, so the bias is correct.

    Which is the answer here, I think... buy MESA tubes at whatever horrendous markup, plug 'em in, and go.
     
  5. Lance

    Lance Member

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    Agreed. They are specifically biased for Boogie output tubes. Preamp tubes, put whatever you want in there. But for power, it's got to be Mesa, or you'll have problems. At least, that's what Mesa told me. I heeded those words, and never tried anything else.
     
  6. DownByLaw

    DownByLaw Supporting Member

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    You'll want to use tubes that are spec'd for the .22. Mesa has them, but a few of the well known vendors will have the right stuff if you tell them it's for the .22. If you want to treat yourself, give Mesa a call and see if they have any NOS Sylvanias on hand. That's all I used in mine as they blew away everything else in that amp. Lasted longer as well. Original equipment in mine.

    Patrick
     
  7. mike80

    mike80 Member

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    Sure, they want you to buy Mesa branded tubes, at a rediculous price. But, they will work with other tubes, and Mesa branded tubes are the worst sounding tubes I've ever had in my amp.

    According to them, they use the equivalent of a Groove Tubes rating between 4 and 7 hardness.

    I've been using JJ E34L tubes for the last two years in my Dual Recto (which I was told weren't within Mesa's specs), and haven't had any problems. I used them for 2 years in another Recto I had before that. Mesas aren't that sensitive that they will blow if you don't use Mesa branded tubes. But, if it's an amp that's under warranty, you should use them just to retain the warranty.

    If you want to be safe, you could contact one of the tube vendors, and let them know your settings and the amp type. Doug's Tubes is one of them, and Bob at Eurotubes can help you on the JJs. I'm not really sure if there are any others out there.
     
  8. mike80

    mike80 Member

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    Also, IIRC, Mesa's EL84s aren't labelled like their normal power tubes are with the color system.
     
  9. art_z

    art_z Silver Supporting Member

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    thanks guys!
     
  10. Blue Strat

    Blue Strat Member

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    All you have to do is order EL84s that are "rated" for a Mesa amp. Several tube dealers know what this means (like us), some don't.
     

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