BDRI troubleshooting help please

Discussion in 'Amp Input - Normal or Bright' started by Uncle Jimmy, May 27, 2020.

  1. Uncle Jimmy

    Uncle Jimmy Senior Stratmaster

    Age:
    72
    Messages:
    1,649
    Joined:
    Aug 22, 2011
    Location:
    Connecticut
    Well, the trusty old blues deluxe reissue went and got all weird on me. volume went WAY down, at first thought a tube. Pulled the back cover off and fired it up. All tubes have a healthy glow, no redplating.

    No sizzled anything on the pcb.

    My money is on the output transformer. When I strum a chord, I can hear it, but it's faint and sounds very far away.

    Any thoughts, advice etc greatly appreciated!
     
  2. Stormy Monday

    Stormy Monday Blooze daddy Silver Member

    Messages:
    13,580
    Joined:
    Jan 19, 2011
    Location:
    almost gone
    I always start with a tube that might have gone
     
  3. archetype

    archetype Senior Stratmaster Silver Member

    Messages:
    3,265
    Joined:
    Nov 26, 2016
    Location:
    Western NY, USA
    Tube time. Start with replacing the output tubes and work backward from there.
     
  4. Vic Interceptor

    Vic Interceptor Strat-Talker

    Messages:
    437
    Joined:
    Dec 28, 2017
    Location:
    Dixie
    no. start with the preamp tube first. Power tubes last. Low volume = preamp tube went out. But the Blues Deluxe and Deville are notorious for their terrible PCB's so do not rule out a grounding issue.
     
    Thrup'ny Bit likes this.
  5. Stevem

    Stevem Senior Stratmaster

    Messages:
    1,372
    Joined:
    Sep 3, 2014
    Location:
    NY
    In a dark room look very closely at the inside of the output tubes when you strum with what would have been a loud chord, if you see the inside of the output tubes flash up brite ( not the orange yellow heater color) when you do that then you indeed have a bad output transformer.

    The tubes flashing up Brite proves out that they are driving the output transformer as they should and the rest of the amp is well, but but the transformer has a shorted winding.

    Inside this hole,( or holes your tubes may have ) that you see in the photo of the plate structure of this 6L6 tube is where you will see the briteness increase as you play.

    Note also that many times the root cause of a failed output transformer is a shorted output tube, even the effect of a long ago shorted output / tube fuse blowing session takes its toll on these marginal made output transformers and the heat brakes down the very thin Enamel insulation on the otherwise bare wires that the transformer is wound with.
     

    Attached Files:

    Last edited: May 28, 2020
    Thrup'ny Bit and Robins like this.
  6. AxemanVR

    AxemanVR I appreciate, therefore I am... Silver Member

    Messages:
    5,066
    Joined:
    Feb 8, 2014
    Location:
    Minnesota USA
    `
    I agree with the others.

    If it is the OT, that's one thing. But, if not, you can't always tell by looking at the tubes. Besides, you should always have a new set on hand anyway, because tubes will go bad eventually...




    `
     
  7. Uncle Jimmy

    Uncle Jimmy Senior Stratmaster

    Age:
    72
    Messages:
    1,649
    Joined:
    Aug 22, 2011
    Location:
    Connecticut
    Thanks all, waiting for a full set of tubes. Going to put a 12ay7 in v1 as ell.