Tube Option

Discussion in 'Amps and Cabs' started by eru, Jan 10, 2008.


  1. eru

    eru Member

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    Self-biased SE A amp, so don't yell at me about biasing.

    what exactly is involved in changing preamp/poweramp tube types (stock is 12ax7/el84) and what kind of variety is actually an option?
     
  2. Blue Strat

    Blue Strat Member

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    Read about preamp tube swaps here. http://www.kcanostubes.com/content/newsletter_details.asp?ArticleID=4

    For power tube swaps, you're very limited with an EL84 amp because most other power tubes have "octal" (8 pin) bases and won't even fit in the same socket.

    The only swap I can think of for an EL84 without rewiring the socket is a 7189/A.
     
  3. rockon1

    rockon1 Member

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    As far as pre amp tubes use can try 5751's,12AT7's 12AY7's,12AV7's,12Au7's(in order of gain reduction) no problem. Bob
     
  4. drbob1

    drbob1 Silver Supporting Member

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    Quick summary: any 12A_ tube (12AX7, 12AY7, 12AU7, 12AZ7, 12AT7) and their military derivatives (you have to check a tube compatibility list, I can only remember the 5651, 7025 off hand). No real substitute for the power tubes, the 7819 is just a military EL84, not significantly different... If you're handy and can rewire the socket for octal preamp tubes (and if the PT can handle the voltage and the OT is somewhere in the ballpark for output resistance) you can open up a lot of possibilities...
     
  5. rockon1

    rockon1 Member

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    Yeah I left out some equivelents... 6072(12AY7),6021(12AT7)6681(12AX7) 7025(low noise 12AX7), 7247(12DW7)5965(12AV7)5963,6189(12AU7)
    Bob
     
  6. eru

    eru Member

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    Thanks, guys.

    I finally put in a 12AT7 today and it made a big difference. I was trying to find a 12AU7, but I don't think I need it.

    Between this and the RC Booster out front that really adds something nice to the clean tone, the speaker/cab is by far the weak point of my rig and will probably be the thing upgraded next.

    -eru
     

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