[sdiy] Ring Mod (was Re: Hadamard Transform Network)

[mskala at ansuz.sooke.bc.ca]

On Fri, 19 May 2017, Paul Perry wrote:
> Shouldn't those filters be 90 degree phase shift allpass filters?

That's a different design.  The Weaver shifter uses two low-pass filters;
the Bode shifter uses two all-pass filters with a 90-degree phase
difference between them in the audio path, though the original Bode patent
( http://www.google.ca/patents/US3800088 ) also described using a
Weaver-type configuration with low-pass filters to generate the
through-zero quadrature carrier.

-- 
Matthew Skala
mskala at ansuz.sooke.bc.ca                 People before principles.
http://ansuz.sooke.bc.ca/