Electrolytic filter caps : Pre - installation longevity ?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by d l x r e v e r b, Jan 6, 2008.

  1. d l x r e v e r b

    d l x r e v e r b Member

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    How long will electrolytic filter capacitors remain good if stored away

    waiting to be installed in equipment ?
     
  2. Frostbite Slim

    Frostbite Slim Supporting Member

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    Really excellent question. I want to know also.
     
  3. phsyconoodler

    phsyconoodler Member

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    One year and then they are unsaleable.Many old ones are still useable as long as you re-form them with a variac,but it's best to get new stock and not worry about that.
    So if you see NOS filter caps on E-Bay,don't buy them unless you know how to re-form them or like swapping them in and out of a complete amp build.
    We can't see inside filter caps to see if the electrolytic compound is dried out,so why take a chance?
    Now I may be wrong here,so those who truly know please pipe in.
     
  4. John Phillips

    John Phillips Member

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    I wouldn't install one over ten years old at all, and not over five years old in a critical application. I don't think I'd draw a line as soon as a year - amps which haven't been turned on for a year or more are usually perfectly OK.

    Basically 'NOS filter caps' are an oxymoron though...
     
  5. 67super

    67super Member

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    Not in the context of guitar amps but in other applications requireing electrolytic caps I routinly use stock that is over a year old. Like John said I wouldn't use something 10 and maybe even 5 but 1 or 2 years has never been a problem.
     
  6. teleamp

    teleamp Senior Member

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    I have read somewhere that the shelf life of new production electrolytics is 5 years. After 5 years, reforming is suggested.

    MikeY
     
  7. SatelliteAmps

    SatelliteAmps Member

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