HELP with tube change!

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by vladorg, Jun 19, 2004.


  1. vladorg

    vladorg Supporting Member

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    Hi guys,
    I'm trying to change the tubes in my Mesa DC 5 amp so I had Bob Pletka from www.eurotubes.com send me a full set of JJ's for my DC 5 - 6 12AX7's and 2 6L6GC's. The problem is that one of the 12AX7's that he sent me is labeled as a balanced tube for the phase inverter?!?!?Here's my question-does anyone know which slot is for the phase inverter(imagine that the 12AX7 tubes are six in line #1 being the one closest to the input jack)?Any help or suggestions are greatly appreciated!!!Thanks in advance,

    Vlad
     
  2. VaughnC

    VaughnC Supporting Member

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    While I'm not intimately familiar with the DC5, generally speaking, due to the typical signal flow in a guitar amp, the phase inverter tube is usually the one that's nearest to the output tubes.
     
  3. vladorg

    vladorg Supporting Member

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    Thanks for the reply Vaughn,here's teh problem though-I've heard that also but the tube layout on the DC 5 makes the first 6L6(closer to input jack) over 12AX7 #2 and the second 6L6 almost over 12AX7 #4 and in between is 12AX7 #3. So?!?
     
  4. vladorg

    vladorg Supporting Member

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    It's all figured out now-it was teh V6 preamp tube.the furthest awy from the input jack and certainly not the closest to the power tubes.This amp now sings BTW.I almost had forgotten how much Mesa tubes sucked and the JJ's rocked:dude
     
  5. GreenTea

    GreenTea Member

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    For my Traynor YCV-40, the "balanced" 12ax7 is the farthest preamp tube from the power tubes. Call Bob or check the schmatic for your amp.
     
  6. vladorg

    vladorg Supporting Member

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    Hey skeltone,
    pretty much the same applies to the DC-5.Like I said before it is all fixed now.Thanks,

    Vlad
     

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