Help - I screwed something up

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by @randall, Jan 17, 2015.

  1. @randall

    @randall Member

    Jan 13, 2015
    Canton, GA
    I just finished installing the Fromel mod on my HRDV. I must have mixed up something in the installation, because my pots are all mixed up. Anybody have any ideas? Here are the details.

    In the clean channel, when all pots are turned to zero and I turn up the clean volume, I get no volume.
    But when I turn up the MID I get volume.
    When the MID pot is up and I’m playing and I turn up the clean VOLUME pot, it acts like a second gain and makes the volume even louder.
    REVERB works
    PRESENCE works
    TREBLE works
    BASS works … but also adds gain
    When I turn on the drive channel, I get no volume from any of the pots unless I’ve got the DRIVE and MASTER pots all the way up, and then I just hear a whisper of overdrive … very faint, almost no volume.

    I know nobody can diagnose an amp over email, but am wondering if I should go through the all the steps again and check my work. There were a few places on the PCB where the previous owner had pulled up solder pads, and I had to either scrape open a trace and solder to it, or solder to the next point in the circuit path. I do have continuity everywhere though, the power tubes are biased correctly, etc.
  2. Bush

    Bush Member

    Dec 29, 2014
    I'd start by taking another look at the schematic.

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