Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!jarthur!usc!apple!portal!cup.portal.com!R_Tim_Coslet
From: R_Tim_Coslet@cup.portal.com
Newsgroups: sci.electronics
Subject: Re: Need  circuit to drop music an octave
Message-ID: <32424@cup.portal.com>
Date: 4 Aug 90 02:46:17 GMT
References: <1990Jul20.223615.4305@portia.Stanford.EDU>
  <1332@fs1.ee.ubc.ca> <58975@lanl.gov>
Organization: The Portal System (TM)
Lines: 31

In article <1332@fs1.ee.ubc.ca>, jthornto@fs1.ee.ubc.ca (THORNTON JOHAN A) writ
es:
= In article <1990Jul20.223615.4305@portia.Stanford.EDU> ceg@nova.stanford.edu 
(Chris Gronbeck) writes:
=>
=>I'm looking for suggestions as to the best way to design a circuit to
=>drop music
=>one or more octaves.  A typlical application being making an electric guitar
=>perform like a bass.  Any hints would be useful.  Thanks.
=>
= 
= The basic octavo circuit is:
=   - send the signal into a clipper    __|~~
=   - feed output into a divide by two flip-flop
=   - wave-shape the output (filter...)

NO! The clipper by itself will destroy the "signal" information.

The only way I know of that will definitely do what you want is a
Digital Signal Processor doing a Fast Fourier Transform on the input,
divide the "frequencies" obtained by 2, and inverse Fourier Transform
to generate the output.

There is probably some less expensive "Analog" method (probably using
"modulators" of some sort) to rearange the spectrum, but I am not that
familiar with this.

                                        R. Tim Coslet

Usenet: R_Tim_Coslet@cup.portal.com
BIX:    r.tim_coslet