'synthetic' Ge transistor?

[jean-charles maillet]

>Of course, if anyone has an idea for a ckt that allows a
>synthetic transistor to be made with selectable characteristics
>this would be a boon to all those struggling to replace oddball
>ones in lightning struck bits of vintage gear.....
>
>hopefully,
>paul perry melbourne australia

Paul,

I have recently submitted an article to Glass Audio which details a new
algorithm for modeling Vacuum Tube Triodes though it could be applied to
transistors with soft knee responses.  Although I don't mention it in the
article the polynomial functions which are used in the algorithm could be
synthsized using translinear circuit concepts devised by Seevink.  In
essence transistor circuits now have the potential of duplicating the large
signal characteristics of VT devices AND circuits ... though it would
probably involve fairly large topologies and therefore would only appeal to
big guys like SONY who could afford the R$D cost of chip fabbing.  At some
point in the future I will look into a discrete implementation.  You may
want to take a look at my webpage for the details.

On a brighter note, I too spent many years looking to source good germanium
transistors for Fuzz Face pedals and others who specialise in the fuzz
things have found better sources for these devices (Japan).  I scored a
pair of 2n257's from R.G. Keen in Austin Tx and they work really nice ...
this latest version of the Fuzz Face comes very close to the real thing.
You can reach him at keen at mail.eden.com

jc

/////////////////////////////   vivaAnalog    \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

/////////////////////   http://www.lynx.bc.ca/~jc/    \\\\\\\\\\\\\\\\\\\\\\\

     Vacuum tube modeling - Great guitar players - Traynor amp schematics

//////////////////////////////////
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\