PSA: Do you verify your cab wiring/switching?

Discussion in 'Amp Tech Center' started by clintj, Apr 16, 2018.

  1. clintj

    clintj Friend of Leo's

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    This came up during some work on a Marshall 1960A cab last week. Had the whole thing apart, and upon reassembly and testing found one that slipped by QA.

    For background, these cabs are selectable for either dual 8 ohm stereo, or mono in 4 or 16 ohm. The readings checked out correct for each side in stereo, but I got 8 or 16 in mono. After some tracing, I got out the magnifier goggles and found what's in the below pic. One set of pins for a jack was never soldered to the board 21 years ago. Soldered it, and it tested correct.

    This cab had been running on two speakers when 4 ohm mode, which would have halved its power rating. IMG_20180411_135707.jpg
     
    robrob and Wally like this.
  2. Wally

    Wally Telefied Ad Free Member

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    Good catch! This is why I suggest to players that they have a multimeter and learn how to check impedances.
     
    muscmp likes this.
  3. Paulie Walnuts

    Paulie Walnuts Tele-Meister

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    Wow someone is going to be very happy after that amp servicing
     
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