[sdiy] HPFs and ADSRs

[David G. Dixon]

> Search on "Bach" on this page:
> 
> http://schematica.com/resources/A_list_of_active_filter_circuit_topologies
> .htm

Wow, that's a lot of filter topologies!  Do they all sound more or less the
same?  Has anyone ever tried to build them all to compare?  Perhaps what we
need is an active filter lab module where all these different topologies
could be created by moving patch cords around and/or flipping switches.

Sounds like a good way to spend a sleepless night...