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Whats the Bias on a tube preamp???

Discussion in 'Amps and Cabs [BG]' started by vene-nemesis, Jan 12, 2006.


  1. vene-nemesis

    vene-nemesis Banned

    Jul 17, 2003
    Bilbao España
    ...and how do you reset it???
     
  2. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    Most preamp tubes are cathode biased. This means, there really is no bias adjustment. You just have to worry about proper gain factors.
     
  3. vene-nemesis

    vene-nemesis Banned

    Jul 17, 2003
    Bilbao España
    Im asking because ampeg claims that i should ask the repairman to reset the bias of the SVP-pro when it gets new tubes.
     
  4. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    Well, if it is anything like the swr IOD, there is actually a power tube in it that does need biasing. They may have had it set up to actually have a bias adjustment. Without a schematic, I couldn't begin to tell you how.
     
  5. vene-nemesis

    vene-nemesis Banned

    Jul 17, 2003
    Bilbao España
    Aww i just have the block diagram :bawl: ...