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From: todd@ivucsb.sba.ca.us (Todd Day)
Newsgroups: comp.dsp
Subject: Designing the analog filter adendum
Message-ID: <1989Sep27.030845.2927@ivucsb.sba.ca.us>
Date: 27 Sep 89 03:08:45 GMT
Reply-To: todd@ivucsb.sba.ca.us (Todd Day)
Organization: Disillusioned Graduate Hackers, Santa Barbara, CA
Lines: 16

I forgot to mention what analog filter I chose and why.

I chose Chebychev because it has no ripple in the passband and
takes half as many poles as the Butterworth.  Each complex pole
pair can be done with one op-amp, so the fewer pairs, the better.
However, we do have a phase problem.  My Chebychev design has a
phase lag of 180 degrees at 20kHz.  The phase starts taking off
at about 2kHz.  This is no big deal for me, as I am dealing with
yucky movie and TV signals, but for those hi-fi nuts who buy
expensive cable and interconnects, this is bloody murder...

-- 

Todd Day  |  todd@ivucsb.sba.ca.us  |  ivucsb!todd@anise.acc.com
"Ya know, some day these scientists are going to invent something
	that can outsmart a rabbit" -- Bugs Bunny