Vintage Synth Repair

On Thursday 30 August 2007 20:00, David Vandenberg wrote:
> --- In vintagesynthrepair@yahoogroups.com, "Roy J. Tellason"
>
> <rtellason@...> wrote:
> > I get really tired of seeing this -- it's not that often that necessary.
> >
> > > I would also replace the positive and negative voltage
> > > regulators (their cheap)
> >
> > Ditto.  Those are not common failure items.
>
> That's funny, in the 30 years I have been restoring these old synths,
> 90% of the power supply problems I ran into, where either bad caps or
> blown voltage regulators.

Thirty years ago (and I've been a tech somewhat longer than that,  got my CET 
in 1981!) there weren't all that many "old synths" around...

Yeah,  3-terminal regulators do fail.  Occasionally.  *Very* occasionally.  
I'd suspect a lot of other tihngs before blindly replacing those,  unless I 
had reason to suspect that the design was poor and that the device had become 
thermally stressed.

Caps are another story,  and they do need to be replaced sometimes.  But not 
blindly,  en masse,  with only a few exceptions -- those black-bodied units 
with one red end were bad news in certain Thomas organs,  ferinstance.

-- 
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"
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Information is more dangerous than cannon to a society ruled by lies. --James 
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