PC Power Supply for DIY

[Paul Schreiber]

Never use a switcher for audio unles you really know what's going on. Besides the noise (100's of mv), most switchers require a minimum load of 15% of the max. rated, or else they go out of regulation.

Like Tony said: use a linear. Look in Allied or Newark for Condor, Elpac, or Power One supplies (the good old 723 regulator is our friend!).

Paul Schreiber
Synthesis Technology
www.why.net/users/paults  The CEM HomePage!

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From: 	Tony Clark[SMTP:clark at andrews.edu]
Sent: 	Saturday, February 22, 1997 2:21 PM
To: 	Fred Becker
Cc: 	synth-diy at horus.sara.nl
Subject: 	Re: PC Power Supply for DIY

> I can get an old IBM PC for $10.  Is the power supply useful for powering a
> synth DIY project?  I would think so.  Would I have to keep the noisy fan?
> 
> Fred

   I wouldn't use one.  PC power supplies typically are good for only 
+5V, as most everything in a computer is run on that.  So the ratings on 
a PC power supply are something like this:  +5V @ 1.5A  +12V @ 0.4A
-12V @ 0.1A.
   Since most synth circuits only use +-12V (or 15) the current 
requirements aren't good enough.  That, and the PC supplies are hideously 
noisy!
   The better bet is to buy a good linear power supply.  I just ordered 
one made by Condor.  It'll push out +-15V @ 3.0A with less than 3mVpp 
ripple.  Now THAT's clean!  And it runs for $91.00 from Allied 
Electronics.

   Tony

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I can't drive (my Moog) 55!
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Tony Clark -- clark at andrews.edu 
http://www.andrews.edu/~clark
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