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Yamaha CA 401

Discussion in 'Yamaha' started by bond.70, Oct 12, 2018.

  1. bond.70

    bond.70 New Member

    Messages:
    25
    Bought for 42€ few days ago, good overall conditions, connected to my ipod then to Sennheiser Momentum headphones, really disappointed, the sound was flat, without bass, Phil Collins seemed a ghost!...with headphones directly to ipod the sound is big, full of details, crispy and Collins is so real and present!...not only the amp was not able to give me more audio level but it was able to ruin completely the sound!
     

     

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  2. avionic

    avionic " Black Knights " Subscriber

    Messages:
    42,959
    Location:
    Fort Dodge, Iowa
    CA-410 perhaps? Bad tantalum caps in the tone circuit.Probably a few electrolytic capacitors past their prime.As well as drifted fusible resistors. Check the idle current/bias.

    [​IMG]
     
  3. avionic

    avionic " Black Knights " Subscriber

    Messages:
    42,959
    Location:
    Fort Dodge, Iowa
    Not to mention dirty switches and controls.
     
  4. bond.70

    bond.70 New Member

    Messages:
    25
    330F4874-F7EF-4429-A232-39D561DD39C4.jpeg B837FB9C-3268-47B3-A2D0-7CD731750C18.jpeg 31E59B64-81EC-4721-AFD3-53837CDEC1DC.jpeg
     
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  5. bond.70

    bond.70 New Member

    Messages:
    25
    Hi yes sorry CA-410
     
  6. avionic

    avionic " Black Knights " Subscriber

    Messages:
    42,959
    Location:
    Fort Dodge, Iowa
    Looks in pretty good shape..
     

     

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  7. bond.70

    bond.70 New Member

    Messages:
    25
    Yes it has only two tiny almost invisible marks around the input selector and one small chip on the wood were I will put a bit of wood putty to fill the imperfection...but as you said I have to check inside and I'm quite sure it needs a full recap!
     
  8. bond.70

    bond.70 New Member

    Messages:
    25
    Opened it and found one of the two big 4700uf caps a bit swallen on top...
    All the other caps are Nichicon some tantalum caps around...
     
  9. amr2

    amr2 Well-Known Member

    Messages:
    520
    I would do a full recap. I’m sure it will sound very good once revisted.
     
  10. bond.70

    bond.70 New Member

    Messages:
    25
    first I would put a couple of Nichicon 6800uf 63V in place of the old 4700uf 40V then to follow all the others electrolytics they are Nichicon as well but 40 years old, but what about the tantalums? the tone control board is full of them for example...
     
  11. amr2

    amr2 Well-Known Member

    Messages:
    520
    Personally I don’t like tantalums, they have tendency to create short circuit failures. Depending on the position in the circuit, I usually change them with film or Low Leakage (UKL).
     

     

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  12. amr2

    amr2 Well-Known Member

    Messages:
    520
    But you can leave the tantalums alone
     
  13. avionic

    avionic " Black Knights " Subscriber

    Messages:
    42,959
    Location:
    Fort Dodge, Iowa
    Get rid of the tantalums..Especially in the tone board.
     

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