[sdiy] Lifespan of Electrolytics?

[Tim Ressel]

Yo,

I have heard tales of woe concerning electrolytics.
One story is that if they are run with a significant
percentage of the working voltage, something bad will
happen. I'm not sure I believe that. Another concern
is electrolytics that have not been used for a long
time. The electrolyte 'goes bad' somehow. You're
supposed to bring the voltage up slowly when firing up
a unit after a long idle period, to 'reform' the
electrolyte. 

I have had none of these problems. However, when I
received my used Heathkit tube power supply, I brought
it up slowly with a variac, just to be safe.

Does anyone have a circuit for testing caps??

--TR



--- Joe Kramer <musetrap at earthlink.net> wrote:
> Hi Folks,
>     I recently got ahold of a Tapco 4400 reverb for
> cheap because one channel
> was dead.  After chasing down a handful of 4136s and
> systematically replacing
> each one, I came to find that the actual problem was
> a bad electrolytic in the
> signal path.  The circuit board is dated 2/17/77. 
> I'm guessing that several
> more of the caps in this board are marginal.  What
> is the expected lifespan of
> electrolytics, and what are the effects of old and
> aging ones?  Is it worth the
> trouble going through any old gear including synths
> that are past, say, about
> twenty years and giving them a electrolytic
> overhaul?  Anyone have firsthand
> (or secondhand) testimonials?  Thanks.
> 
> Regards,
> Joe Kramer
> 
> 
> 
> 
> 
> 


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