Mullard 7189a OK for marshall DSL201?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Roodboy, Feb 4, 2005.


  1. Roodboy

    Roodboy Supporting Member

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    I saw a pair if these tubes which looks sweet, it appears they can handle higher voltages than a regular el84. I think they are a miltary bersion of the el84. However, there is something about a "pinout" on this model which may make it incompatible for certain EL84 amps.
    I have two questions:
    Is the fact that it can handle a higher voltage mean its better?
    I don't know what this "pinout" really means but I would like to know if anyone knows if its OK for the DSL 201.
    Thanks in advance for the help.
    :D
     
  2. Wakarusa

    Wakarusa Member

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    The basing (pinout) on both types should be compatible. Lots of folks run EL84 in old Scott stereos when they don't want to drop the dollars on 7189's

    In addition to having a higher plate voltage rating, the 7189 is (in theory) designed with "high fidelity" in mind.

    I'd run 'em in a DSL201 without thinking twice.
     
  3. Roodboy

    Roodboy Supporting Member

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  4. illinimax

    illinimax Gold Supporting Member

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    Whoa!!! The 7189a is not the same pinout as a 7189 (EL84). Different enough that I'd recommend proceeding with extreme caution. I learned the hard way.
     
  5. hogy

    hogy Member

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    Please do not waste those tubes in that amp.
    No NOS quads of Bugle Boys for Peaveys either (to answer another common question).

    Hogy
     
  6. hogy

    hogy Member

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    That info is not correct. The pinout is the same.

    Hogy
     
  7. illinimax

    illinimax Gold Supporting Member

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    Hogy,
    The slight difference in pinout was enough to screw up my amp. Some (most?) 7189/EL84 circuits are ok with 7189a tubes. I'm just suggesting caution based upon my experience.
    BC
     
  8. hogy

    hogy Member

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    I get it now. The amp you tried them in must have used one of the unused tube socket connections as a solder terminal, either for the screen resistors or the grid stoppers, instead of leaving it unused. In that case there could be a problem.
    You're right, I'm sorry.

    Hogy
     
  9. illinimax

    illinimax Gold Supporting Member

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    No problem Hogy. It's interesting that some amps do that. I've read about other EL84 amps that don't get along with Ei and some NOS tubes for likely the same reason.
     
  10. Roodboy

    Roodboy Supporting Member

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    thanks for the help. I decided to bail on the 7189a and picked up a pair of Tesla (not JJ) El84's.
     
  11. illinimax

    illinimax Gold Supporting Member

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    Good choice. I just put a Tesla EF86 in my Matchless that I really like.
     
  12. Reeek

    Reeek Member

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    I have 8 NIB Tesla ECC803s . They are VERY nice preamp tubes. I rotate the same one around so I keep thea ll the other NIB's new :rolleyes:
     

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