Archive of the former Yahoo!Groups mailing list: MOTM
Subject: Re: [motm] phase shifting WAS: module concept
From: "Paul Schreiber" <synth1@...>
Date: 2000-04-17
A filter can shift one frequency a set amount. BUT...for a anything-in,
anything-out circuit, you cascade
a zillion ∗all-pass filters∗ (also called a PDN: phase-differencing
network). Electronotes had a good
issue on the proper design of these. You need a 90 degree shift from say 20
to 20kHz: takes something
like 14-16 filters in a row. This is what Bode called a "dome filter".
Paul S.