Need help repairing a DOD 690 chorus

Discussion in 'The Stomp Box' started by Salty_critters, Apr 3, 2020.

  1. Salty_critters

    Salty_critters TDPRI Member

    Posts:
    14
    Joined:
    Sep 16, 2018
    Location:
    Virginia
    Hey all, I'm hoping someone on here has some insight into this big-box chorus pedal. It's a DOD 690 Chorus, made in the late seventies I believe. I love the sound of it but it has started making unpleasant distorting noises, almost like a solid-state amp clipping but much harsher. I know next to nothing about solid state circuits or pedals so I'm not sure where to start! I also cannot locate a schematic for this pedal on the net. Any ideas what I should look into replacing?
     

    Attached Files:

  2. Lowerleftcoast

    Lowerleftcoast Tele-Holic

    Posts:
    959
    Joined:
    Dec 30, 2019
    Location:
    california
    Try "chop sticking". Poking at parts and solder joints with a non-conducting chop-stick type device. You are looking for poor solder joints or noisy parts.

    Clean the jacks and pots. The jacks are probably switched. Those switches should get cleaned.

    Aluminum electrolytic capacitors can cause problems when they get old. They are the ones that look like little cans. They are old.

    If any of the parts are in a socket, those contact points should be cleaned as well.
     
    rangercaster likes this.
  3. Salty_critters

    Salty_critters TDPRI Member

    Posts:
    14
    Joined:
    Sep 16, 2018
    Location:
    Virginia
    I guess I should mention, the crackling distortion only happens when a signal is passed through the pedal. At idle it's as quiet as it should be.

    The electrolytics are probably due for replacement, you're right. I'll give all contacts and pots a good scrub, I didnt see any cold joints.
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.