Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site watcgl.UUCP
Path: utzoo!watmath!watcgl!dmmartindale
From: dmmartindale@watcgl.UUCP (Dave Martindale)
Newsgroups: net.audio
Subject: Re: equalizers
Message-ID: <713@watcgl.UUCP>
Date: Thu, 25-Aug-83 11:30:33 EDT
Article-I.D.: watcgl.713
Posted: Thu Aug 25 11:30:33 1983
Date-Received: Fri, 26-Aug-83 08:54:54 EDT
References: <735@hou5e.UUCP>
Organization: U of Waterloo, Ontario
Lines: 11

I have a Southwest Technical Products octave-band equalizer.  It is quite
noisy, and the overshoot on a square wave input is impressive.
I believe that its basic problem is that it uses 5558 op amps, which
are just dual 741's.  They are neither fast nor quiet.  The basic design
puts a group of 9 paralleled bandpass filters within the feedback loop of
another op amp; I believe this makes the circuit much more sensitive to
slow op amps.  However, for $100, I really can't complain too loudly; it
makes a nice toy but it isn't suitable for continuous use.  A friend
has an equalizer (also built from a kit) which didn't cost much more,
and behaves considerably better.  The manufacturer may have been MXR,
but I'm just guessing.