Cap labeling/replacement.

[McElhatton, Pat]

 ----------
From:  cyborg0
Sent:  Thursday, March 05, 1998 3:19 PM
To:  synth-diy
Subject:  Cap labeling/replacement.

HEREs my prob.

I am trying to replace a couple of caps in the PS of my Oddy, since the
ones in the ODDY are oozing badly these days..

OK, first question, the original electrolytics say "250mfd".. Now, I
always was taught that the convention was that all cap values were
listed in microfarads, but "250mfd" LOOKS like millifarads...What is it?
Probably microfarads.  A quarter farad capacitor would be very large   
(much
larger than your synth).



 if i put a larger value cap (the original says 250mfd, and the closest
i could find was 330ufd) could that possible cause a DC offset? I assume
that it could only better the ripple rejection of the PS, but, once
again, thats textbook talking, and I dont have much faith in it lately!
:))
I don't think it will cause a DC offset.  To some extent you can use   
larger caps,
but as you increase the capacitance you increase the surge current when   
the
PS is first turned on, so you run the risk of blowing out diodes and such   
which
can't handle the current.  At least that's what I've seen with a few   
simple power
supplies where I was trying to reduce the AC component by adding in
humungous caps.

answers welcome!
rob