Need to find capacitor for my preamp.

Discussion in 'Community Discussion' started by velocityg4, Jul 17, 2015.

  1. velocityg4 macrumors 68040

    velocityg4

    Joined:
    Dec 19, 2004
    Location:
    Georgia
    #1
    I'm trying to find this specialty audio grade capacitor for my venerable Yamaha Pre-Amp (C-80 as I recall). When in use for an hour or so audio in the right channel will get static or cut out. I've gone over everything on the board. I can't find any cracked solder joints. The pots all seem fine. All I could find were these two slightly bulged capacitors. So I think they are the problem.

    The problem is I can find ones which match their voltage and uf ratings. But they are all two pin and appear to be rather small. While the capacitors I need are four pin and rather large.

    One side reads Nippon Chemi-Con. Audio Neg. Black 85 (degree symbol) C. It appears the part number on top is 58GAH. They are rated (B) 35v4700uf(M), (A)(C) Blank, (-).

    IMG_0937.JPG IMG_0938.JPG IMG_0939.JPG
     
  2. D.T. macrumors 603

    D.T.

    Joined:
    Sep 15, 2011
    Location:
    Vilano Beach, FL
    #2
    Check out mouser.com, that's where I score my caps, they carry a _huge_ assortment, possibly some high grade like you're wanting.
     
  3. chown33, Jul 17, 2015
    Last edited: Jul 17, 2015

    chown33 macrumors 604

    Joined:
    Aug 9, 2009
    #4
    Also try digikey.com for caps.

    Here's the manufacturer of the existing caps:
    http://www.chemi-con.co.jp/e/

    Search their site to find their US distributors.


    Crackling in the output can also be caused by a failing transistor. Basically, it malfunctions when it gets warm.

    It might be a power transistor in the output stage, or one of the small-signal transistors earlier in the amp channel. There might be no visible indication that the transistor is bad. Some freeze-spray may help find it, or it may not.

    Without a schematic and some way to look at signals in the channel (e.g. oscilloscope), you'd probably have to take it to a repair shop.
     

Share This Page