[sdiy] Saw core JFET mystery

[Dave Manley]

On 3/1/2010 12:41 PM, Eric Brombaugh wrote:
>
> Perhaps David meant the "De Franco resistor", a technique discovered by
> Sergio De Franco to improve the response time of JFET reset transistors
> in VCOs? Googling turns up these documents with some details:
>
> http://www.oakleysound.com/vco4-doc.pdf
> http://www.oakleysound.com/vco5-bg.pdf
>
> Eric

More here with schematic:

See R17: http://home.swipnet.se/cfmd/synths/friends/stopp/asm1vco-1.1.pdf

Text: http://home.swipnet.se/cfmd/synths/friends/stopp/#3.1

-Dave

P.S.  It is definitely "De Franco".  Not sure about the "Sergio".  There 
is a UCSF professor Sergio Franco, that has published a number of times 
on synth related circuits.  He also has a relatively good text book on 
opamp circuit design.