[sdiy] improved dynamic range diffpair-vca

[JH.]

>The schematic clearly says "6dB input dynamic range improvement" (which
>it clearly does) and not SNR improvement.  Your derivation of a 3dB SNR
>improvement looks fine to me, so both figures are correct.

Isn't dynamic range the span between a maximum level (clipping point, or a 
certain amount of THD), and the noise floor?

The maximum level is raised by 6dB, and the noise floor is raised by 3dB, 
resulting in 3dB improovement.

JH.