Trying to find specialty capacitor for preamp.?

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.

Since I can only post one picture. The other 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, (-).

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  • 6 years ago
    Favorite Answer

    IT WAS A VERY COMMON VALUE CAPACITOR USING AS A POWER SUPPLY FILTER OR POWER STAGE OUTPUT COUPLING, ANY ELECTROLOYTIC CAPACITOR IN DIFFERENT SIZE CAN BE USED,SELECT CAPACITOR ANY VALUE BETWEEN 4700uF TO 6800uF , VOLATAGE RATE BETWEEN 35V TO 75V SHALL DO.

    HOWEVER, YOUR TROUBLE SHOOTING WAS WRONG, REPLACING THIS CAPACITOR WOULD NOT HEAL THE TROUBLE.

    THOSE CAPACITORS LOOK GOOD FROM IMAGE, TO MAKE SURE THEY WORK WELL OR NOT BEFORE BUYING THEM, TAKE THEM OUT AND MEASURE WITH A GOOD CAPACITOR TESTER AND MAKE SURE DO A LEAKAGE TEST SET TO 35V DC.

  • 6 years ago

    Only two of the leads on your capacitor are actually doing anything electronically, the minus lead and the B lead. The other two are just used for mechanical anchoring. What you can do is carefully measure the lead spacing, then find one at (say) mouser.com that with the same lead spacing. Standard lead spacings for this range of capacitance are 7.5mm and 10 mm. You'll also need to make sure the new capacitor fits within the height and diameter of the old ones, but this is usually not an issue, as technology advances and things tend to get smaller, if anything. If this will be in an environment where vibration is an issue, then you may want to anchor the new capacitor with a bit of silicon cement, in lieu of leads A and C.

  • ?
    Lv 7
    6 years ago

    These are the main power supply caps and they are shared by all channels. Your problem could be a small coupling capacitor but most likely it's a connector, a transistor or IC with a bad bonding wire inside. Get a can of freeze spray and shoot each part (using the straw), especially chips one at a time until you get a reaction. You may also be able to get a reaction by tapping parts with the plastic handle of a screw driver. When you have a part that reacts to the slightest tap and not it's neighbors, that is where to look an or replace the part. It could be that it simply needs the solder remelted or a connector reseated. It is worth while to simply disconnect and reconnect any and all connectors you find. Good luck.

  • Anonymous
    6 years ago

    Check if there is somethinh matching:

    http://www.alliedelec.com/passive-components/capac...

    Nippon Chemi-Con is proabably Nichicon, and it looks like those are snap-in types. Just measure diameter and height.

    And if they are older, the replacement types might well be smaller.. In any case, these look like power supply capacitors - not really critical.

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  • 6 years ago

    What you have is an aluminum electrolytic cap. 35 v / 4700uF. Any cap which is close will work fine if it is a filter cap. It is probably not critical value because it is ~ 20% tolerance.

    http://www.jameco.com/webapp/wcs/stores/servlet/St...

    http://www.digikey.com/product-search/en?pv13=181&...

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