[sdiy] The PAiA 2700 VC LPF

[harry]

I bet the 3904 will work just fine... use some socket pins from
a screw machined type IC socket and plug 'em in until you
get a winner.  The 2n5089 is a good try also...

H^) harry

Scott Gravenhorst wrote:

> I'm looking at this filter again and it's so simple to
> build, well...  I'd prefer to use parts I have lying
> around.  I see that the 2N3391 has a beta of 250.  The
> parts I have here are pretty much 2N3904.  Is there a
> way to make a 'crippled' darlington pair that could
> increase the 2N3904's beta to 250 ?  I understand that
> a simple D-pair will multiply the gains, and I don't
> think 10,000 would be right.  My *guess* is that a
> resistor between the first transistor's emitter and
> the second's base ????  Also, can anyone tell me
> whether this filter is for expo of linear CV?
>
> =========================================================
> - Government: The other religion.
> - The media's credibility should always be questioned.
>
> -- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
> -- Linux Rex         | RedWebMail by RedStarWare
> -- FatMan: www.teklab.com/~chordman
> -- NonFatMan: members.xoom.com/_XMCM/chordman/index.html