DSL20CR Output Transformer

Discussion in 'The Workbench' started by Javimart1212, Jan 26, 2021.

  1. Javimart1212

    Javimart1212 Member

    Joined:
    Jun 21, 2017
    Messages:
    86
    Likes Received:
    68
    So, suddenly my damn P.O.S. DSL20CR started going off with a loud runaway crackle and pop, so loud that it can leave standby without rattling the walls. I thought it was the power tubes and put a new set in; it didn't help. Well as I inadvertently removed the speaker cable from jack, I could hear the output transformer sounding like its sizzling which is the noise that comes through the speaker. Im pretty sure its a goner, but where could I get a new one or one that's compatible? Thanks
     
    Last edited: Jan 26, 2021
  2. KraftyBob

    KraftyBob Well-Known Member Gold Supporting Member

    Joined:
    Sep 5, 2017
    Messages:
    1,839
    Likes Received:
    2,359
    Location:
    Chicago Suburbs - USA
    Do you know for sure your OT is bad? If you didn’t play anything while the cab was unplugged then it’s highly unlikely that did anything. The OT needs a load when it’s being fed a signal. If there’s no signal the OT is sitting idle.

    You should take some measure first to confirm, then order a new one if needed. You can check with Mercury Magnetic’s but they are typically higher priced. Also look for Heyboer and Hammond.

    Try plugging your guitar directly into the effects return. If you have sound then the problem is not in the power amp section. Start rolling preamp tubes.

    If you need to check your OT disconnect it and between any primary and secondary lead make sure there isn't a short. Check each side to ground (metal housing when disconnected) - there shouldn’t be a connection. On the primary side check the ohms between the center tap and each plate wire - it should measure approximately the same. Then check ohms between the two plate wires - it should be double the center tap reading. Measuring ohms between the secondary wires should yield essentially 0 ohms. It doesn’t work like the primary side.
     
    Last edited: Jan 26, 2021
    tce63 likes this.
  3. Javimart1212

    Javimart1212 Member

    Joined:
    Jun 21, 2017
    Messages:
    86
    Likes Received:
    68
    I can't even take it off of standby without getting slammed by that noise. It is super loud so I cannot test the effects return. The OT sounds like it's sizzling when no speaker is plugged in, and as soon as I do, BAM deafening sound.
     
  4. thetragichero

    thetragichero Well-Known Member

    Joined:
    Jun 6, 2010
    Messages:
    3,113
    Likes Received:
    1,062
    Location:
    flo rida
    sounds like your amp is sick. have it looked at by a qualified professional
     
  5. KraftyBob

    KraftyBob Well-Known Member Gold Supporting Member

    Joined:
    Sep 5, 2017
    Messages:
    1,839
    Likes Received:
    2,359
    Location:
    Chicago Suburbs - USA
    Try swapping the preamp tubes. Easy enough to do to rule that out.
     
  6. Gene Ballzz

    Gene Ballzz Well-Known Member

    Joined:
    Feb 19, 2013
    Messages:
    2,456
    Likes Received:
    2,225
    Location:
    Las Vegas, NV
    Yes! Or even try firing it up with no preamp tubes. If it fires up with out the noise, you know it not a problem in the OT/power section. Then one by one (starting with the PI/closest to the power tubes) begin to re-install. Cheap and easy troubleshooting!
    Just A Thought?
    Gene
     
    KraftyBob and Guitar-Rocker like this.

Share This Page