Hi,

>   I thought the MF-6 was simply a switched-capacitor "boxcar" filter
> like you are already using for the primary filter?  How does it reject
> harmonics?

Switched capacitor filters are analogous to conventional multi oppamp
filters such as Biquad or State Variable.

They merely use the switched capacitor as a (sort of) digitally variable
resistor.

They don't respond to harmonics.

The Commutating Filter is a completely different beast, which DOES respond
to harmonics.

Personally, I think that Box Car Integrator is the wrong term for
these.......

cheers ............. Zim