Re(2): 2nd generation VCFs (was: Xpander VCF)

[tomg]

The mirror isn't up-down from stage to stage. It's side to
side in the stage....ie the current through the right transistor
is mirrored through the left....

Tom


> >The patent
> >calls for n,p,n,p current mirrors. n,n,n,n also works but has about
> >1/2 the gain. 
> 
> How could that be ? Current mirror means reverting the direction, so
> how could it possibly work with npn only ??