Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site peora.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!decwrl!pyramid!pesnta!peora!jer
From: jer@peora.UUCP (J. Eric Roskos)
Newsgroups: net.music.synth
Subject: Re: Digital Reverb? (& delay)
Message-ID: <2048@peora.UUCP>
Date: Wed, 26-Mar-86 08:54:56 EST
Article-I.D.: peora.2048
Posted: Wed Mar 26 08:54:56 1986
Date-Received: Thu, 27-Mar-86 07:44:40 EST
References: <3095@potomac.UUCP> <2913@sjuvax.UUCP> <2920@sjuvax.UUCP> <943@pucc-j> <1141@unc.unc.UUCP>
Organization: Concurrent Computer Corporation, Orlando, Fl
Lines: 19
Keywords: Delay line, shift register, RAM

> Of course, a long hardware shift register should be easier to control
> than the RAM, but I didn't realize that such a register exists (unless
> you're referring to an analog bucket-brigade delay line). Is this really
> what is used in the commercial digital delays?

Yes... there is a 1024-bit shift register, the SAD-1024, made specifically
for this purpose.  I remember it was used in two of the (much-maligned)
PAIA analog synthesizer kits I built a few years back, before digital
synthesizers became affordable.  If I recall correctly, it's really two
512-bit shift registers in the same package, which you can chain together;
this gives you access to the middle of the shift register.  Some chorusing
circuits I've seen work by slightly varying the rate at which the register
is clocked, which cause slight phase and frequency shifts.  I think Radio
Shack used to carry the SAD-1024 when it first came out, but I think
they quit carrying it after awhile.
-- 
E. Roskos

"It's Halley's comet!"