[sdiy] Genital Electric P/V converter LIVES

[Ken Stone]

It is a pitch to voltage converter that was frequently (but not always)
found in Serge panels.

Ken

>Way to go Harry!  Woo Hoo!  You da man!
>
>Just one thing: What the hell is a GE-101 PV
>converter?
>
>--TimR
>
>--- Harry Bissell Jr <harrybissell at prodigy.net> wrote:
>
>> My Gentle Electric GE-101 PV converter has come
>> back from the grave. I bought it "as is but in good
>> shape" from someone on AH. It was blown to kingdom
>> come, probably from reverse voltage on the power
>> supplies. I paid way too much for it in the
>> condition
>> received (but hey, it was 'as-is' right ???)
>> 
>> My first clues to an amateur repair attempt was that
>> ALL THE ELECTROLYTIC caps were replaced, cheap
>> sockets
>> were inserted for all the opamps (also replaced).
>> 
>> another clue. One IC had the non inverting input
>> drilled OFF CENTER to accomodate a guard ring
>> (common
>> S/H technique).  The person (dis)effecting the
>> repair
>> put in an IC socket with that pin 'folded under' so
>> no
>> connection was made. Were they going to hook it up
>> later, or did they just bone it ???  I think (from
>> the
>> mass capacitor destruction) the latter...
>> 
>> Sad is that the potted modules (2) were blown out...
>> the fundamental extractor AND the expo module. Even
>> the 2K Q81 tempco was toast. All the cmos chips were
>> trashed, as well as a large number of transistors
>> and
>> diodes.
>> 
>> Glad is that I was able to reverse engineer the
>> modules
>> with hammer, chisel, and propane torch.  I just
>> found
>> the last problem, which was a defective opamp that
>> still worked, but maybe had an extrememly LOW input
>> impedance due to internal damage.  Replaced it with,
>> yup... a 741 and it started working. OK so 741's
>> suck... but I'm fresh out of LM301s
>> 
>> It was a lot of pain to fix this, but I wanted it
>> for
>> educational purposes. If it HAD worked, would I have
>> smashed the potted modules open ???  Probably not.
>> How well does it work ?  I'm not sure yet, but it
>> does
>> the P/V thing as advertised.
>> 
>> Maybe when its in a box, I should send it to another
>> Gentle Electric owner for an A/B test ???   :^P
>> 
>> Anyway... I just wanted everyone to know there is
>> life-after-talking-about-your-manhood on s-diy 
>> 
>> H^) harry
>> 
>
>
>
>		
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>
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au or sasami at cgs.synth.net
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>