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Path: utzoo!watmath!clyde!cbosgd!ihnp4!tellab1!etan
From: etan@tellab1.UUCP (Nate Stelton)
Newsgroups: net.music,net.music.synth
Subject: Re: Digital Reverb?
Message-ID: <858@tellab1.UUCP>
Date: Mon, 24-Mar-86 10:28:08 EST
Article-I.D.: tellab1.858
Posted: Mon Mar 24 10:28:08 1986
Date-Received: Thu, 27-Mar-86 06:40:54 EST
References: <3095@potomac.UUCP> <2913@sjuvax.UUCP> <2920@sjuvax.UUCP>
Reply-To: etan@tellab1.UUCP (Nate Stelton)
Organization: Tellabs, Inc., Lisle, IL
Lines: 32
Xref: watmath net.music:12867 net.music.synth:969

In article <2920@sjuvax.UUCP> lp102918@sjuvax.UUCP (Larry Palena) writes:
>       ...I know this is gonna sound like a stupid question,but hey!!!,
>       stupidity is a virtue.What is *digital* about digital delays??
>       Do they sample the delayed signal,or use microprocessors 
>      to control feedback,or both??...

I'm no expert, but my understanding of DDL's is that the sound is sampled
much the same way that digital recorders, digital phone lines, and sampling
keyboards perform this task.  The information is stored in RAM, and released
at the end of it's sample duration (set by the 'delay' knob).  DDL's are
functionally the same as an echoplex.  I believe microprocessors are used to
control the management of the memory in terms of how long to sample, when to
write over what parts of memory, and more recently, extensive MIDI and user
interface.

>      ...also,why has mechanical (ie. spring-controlled) reverb died??
>      Was it particularly prone to failure? I have a Fender-Twin (circa.
>      '69) with mechanical that doesn't work,but when it did I thought
>      it was *fantastic*,super-genuine!!...

I wouldn't say it's died yet, but eventually...  The main problems with
spring reverbs are the "boing" (try mixing drum tracks through one), and the
physical sensitivity (don't bump it with the amp cranked, and don't drop it
while moving the equipment).  As far as mechanical reverbs go, plate reverbs
out-perform the springs for sound quality, but they haven't figured out how
to put them in guitar amps yet.

I am curious about how digital reverbs work.  how do they produce the smear?
How many samples are taken, played back, and heard at a given point in time?
Anyone care to expound?

                                    -etan