Forum Top Banner Ad


Ebay Classic organs



No announcement yet.

Hum problem on one channel on Rodgers 580

This topic is closed.
  • Filter
  • Time
  • Show
Clear All
new posts

  • Hum problem on one channel on Rodgers 580

    I am now the proud owner of a Rodgers 580 digital organ. This organ was dead when I got it, but after extensive work, and rebuilding the keyboards with the glue problem, plays pretty good. However, I have 2 problems. One of them sounds like a transformer buzz, and the other is hum on 1 channel. I had to rebuild the audio pre-amp due to the 1000mfd 35v capacitors leaked and caused some minor damage to the board. After cleaning and replacing the caps, was able to get the organ to play. The hum is also heard through the headphones. When connecting the external speakers, the hum is there, but not as bad, but the transformer buzz sounds like it is being amplified. This is the only thing that is keeping me from getting this organ ready to put on the market. Hope someone can give me some suggestions. I'm thinking one of the caps I replaced could be bad, but not sure. B630

  • #2
    if a cap were bad, you'd have hum on both channels equally, as the two caps filter the + and - legs of the 12 volt supply, used by both channels.

    Transformers like that do sometimes buzz, and the cure is simply to isolate it mechanically some way from the console. I had to do this when I owned a 580 by loosening the screws that held it down and installing some felt washers under the feet. You'll have to tinker with it until you find a solution.

    The hum is almost surely a grounding problem with the one channel. You'll just have to check and double-check everything to try to find it. Check cables and other places where signal exits and enters different boards.
    *** Please post your questions about technical service or repair matters ON THE FORUM. Do not send your questions to me or another member by private message. Information shared is for the benefit of the entire organ community, but other folks will not be helped by information we exchange in private messages!


    • #3
      Sounds like a good suggestion. I'll check the grounds and try cushioning the power transformer. Thanks for the info.


      • #4
        After cushioning the transformer, and found the power transformer itself was not properly grounded, eliminated the hum and have a slight bit of white noise. However, when bringing the volume level down a bit, that was eliminated. Thanks for all your help on this issue. Now it's ready to sell.