Marshall & Dr. Z out of phase with ABY Box -- HELP!

Discussion in 'Amps and Cabs' started by imguitardan, Jan 22, 2008.


  1. imguitardan

    imguitardan Member

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    These two amps sound great. I'm using a Dr. Z Mazerati (AC30 type head) with a '73 Marshall Super Lead through a Morley ABY box and into the same open back 212 with the speakers separated (Vintage 30's). One amp to each 8 ohm speaker. Each amp sounds great in the A OR B mode but when I combine the two (A AND B) the bass drops out and it sounds anemic and weak. Is this fixable? Did I do something wrong?

    BTW: I have both amps in the same electrical output but I put a gray ground lift on one of the amps so there's no ground loop noise. Any help would be appreciated.
     
  2. doublee

    doublee Member

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    It doesnt have a 'phase' button? If not, maybe putting a buffered box before the aby may help
     
  3. imguitardan

    imguitardan Member

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    How do I know if I have a buffered box?
     
  4. boltino

    boltino Member

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    Radial makes a couple of ABYs with a phase switch on them. That should fix the problem.

    You might be able to wire a speaker cable with a flipped phase to remedy this as well. (Not 100% positive if this is ok, it should be, but maybe someone else can chime in)
     
  5. Edmundo

    Edmundo Supporting Member

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    Flips the leads at the end of one your speaker cables...done.
     
  6. welcometoashley

    welcometoashley Supporting Member

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    barber makes the launch pad that can correct out-of-phase amps when using two...
     
  7. imguitardan

    imguitardan Member

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    If the phase issue isn't the problem, will switching the leads on the speaker cable hurt anything? What if I use that cable with a different amp/setup...will that be OK?
     
  8. Edmundo

    Edmundo Supporting Member

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    Nope
    Yup
     
  9. imguitardan

    imguitardan Member

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    Sweet! I hope that works. The iron is heating as I type...
     
  10. Edmundo

    Edmundo Supporting Member

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    It's always good to keep a flipped-phase speaker cable handy. :AOK
     
  11. imguitardan

    imguitardan Member

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    Just to make sure...I'm switching one end of my speaker cable's negative and positive wires and leaving the other end normal?
     
  12. imguitardan

    imguitardan Member

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    Please confirm that the above post is the correct procedure...but it sounds like it worked!
     
  13. dorianadams

    dorianadams Member

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    Love that phase reverse swiitch on Matchless amps. Huge time saver for such a simple( and rare for some reason) feature.
     
  14. boltino

    boltino Member

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    yep, that's correct.

    Me too. :AOK
     

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