[sdiy] Discrete blackmer vca

[James Patchell]

Anybody here experiment making Blackmer VCA's from discrete 
transistors?  I know it has been done.   I am pretty sure Hearn Morley 
does or will sell a discrete one in a module.  I thought it might be fun 
to experiment a bit with them.  Kind of the cool thing about them is 
that they take an input current and produce an output current with a 
gain that is controled by a voltage.

For those who may not know what a blackmer vca is, here is a link to a 
prelim schematic of a very basic (and descrete) BMvca

http://www.noniandjim.com/Jim/SMB2/SMB2.html

-Jim