EC ZDS hum from one channel

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by The Killer Piglet, Nov 14, 2016.

  1. The Killer Piglet

    The Killer Piglet New

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    Well, it was a long shot at best but it was not the rectifier tube.
     
  2. bazelio

    bazelio Friend

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    Did you swap power tubes left to right?
    Did you try a completely new/different 6SL7 tube?
    Does the hum respond to the volume control?
    Do you have a second amp that you can connect to a ZDS preamp output to see if the hum is still amplified?
     
  3. The Killer Piglet

    The Killer Piglet New

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    Yes
    Yes
    No
    Had not tried, just did, yes
     
  4. bazelio

    bazelio Friend

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    Can you tell if it's a 120 Hz hum? I would guess it is (?) and then maybe there's something either wrong with a filter cap or some filter cap solder joint, etc. Totally a WAG, though.
     
  5. The Killer Piglet

    The Killer Piglet New

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    It sounds very much in that range
     
  6. The Killer Piglet

    The Killer Piglet New

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    Hi, folks

    to provide closure, I communicated with Mr. Uthus yesterday.
    He suggested checking a couple of solder points.
    Today I did so, and amp is in perfect working order now.

    Thank you, gentlemen, for your assistance and support.

    Hiram
     
  7. purr1n

    purr1n Desire for betterer is endless.

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    Glad he finally got a hold of you. I spoke to him yesterday too. First time since I learned that he broke his arm. He said that he would have rather it been chopped off.
     
  8. The Killer Piglet

    The Killer Piglet New

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    Ouch... pure coincidence, I'd not tried to reach him over the holidays; first email got instant response.
     
  9. khragon

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    I'm curious, which solder was it that was giving you trouble? Did you have to re-solder?

    Thanks.
     
  10. The Killer Piglet

    The Killer Piglet New

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    One of the large caps had lost a connection, added a drop of solder.
     
  11. khragon

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    Good to know, something to keep in mind. Thanks for the info.
     
  12. liamstrain

    liamstrain MOT: The Audio Guild

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    Good news!
     

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