From: Lee Silverman <ST101137@brownvm.brown.edu>
Subject: Dolby Stuff
Reply-To: ST101137@brownvm.brown.edu
Organization: The Internet
Date: Tue, 14 Apr 1992 20:28:39 GMT

|Don't blame Dolby for bad tape decks
  (or something to that effect, said by R. Stern)

I agree.  Dolby is a great system, and I use Dolby B all the time.
I'm not perpared to ask anyone to go out and spend the money that I've
spent on my two tape decks (which, by the way, wouldn't have bought
*half* or Richard's Nak Dragon) but consider this reason to use dolby:

Many people argue that dolby cuts down the high-frequency response of
a tape.  I agree WHOLEHEARTEDLY.  It most certainly does, and Ihor's
discussion with the guys at Dolby proves that.  But it cuts it minimally.
Compare that cut to the damage done to a tape by the piles and piles
of hiss that get added when you don't use NR.  More of the high-end is
obscured by the hiss than gets cut out by dolby, for the same number
of generations of copies.

Don't believe me?  Good, that shows you're thinking, at least.
Go home and try it.  Make a 10th generation tape of a CD, so you know
you have a clean source.  Copy the first one using No NR.  Copy the
second one by using the CORRECT method of using Dolby B with your setup.
Now, listen and decide which sounds better.  If they both sound like crap,
then either:A)You did something wrong with the dolby.  B)You need
to recalibrate your decks; take them to a repair shop. C)You need
better tape decks, or D)You need to lower your standards.

The generally accepted method of copying a tape with Dolby:
On just about every dubbing deck in the world, you'll find only one
dolby switch; that means that you can't both ENCODE and DECODE the
dolby.  So record the first time (from the CD) using Dolby, but don't
use it afterwards; just do the copying straight.  To play it back,
however, use NR.  It'll decode the originally encoded signal.

If you want, try it with dolby on the whole time, and see if that works.
Different manufacturers do things differently.

If you have two single decks, to copy a dolby tape use Dolby to play back
and dolby to record.  Playing back with dolby gives you a CLEAN, unencoded
signal to work with, and recording with dolby encodes it for that tape
correctly.

Now, judge for yourself which tape sounds better, and on that basis,
decide whether or not you like dolby.

I did a 15 gen copy test a few nights ago.  I must admit that
neither of the tapes were any better for the wear.  However, a few points:
The Dolby C tape didn't survive past 6 gens.  Switching between decks
has shown me that Dolby C is untransportable and shouldn't be used for trading
tapes.
The no NR tape had a good bit of signal on it, but probably just as
much hiss.  The amount of hiss seems to be added exponentially as
the generations go up; almost none at 5 gens, audible at 7, impinging
at 11, dominating at 13, and roaring at 15.   I could hardly hear the
music over the hiss.
The dolby B tape also had hiss, but not so much that the tape was
unlistenable. It also had a significant portion of the high end
missing.  But it sure sounded better than the no n/r tape!

Since 10 gens isn't a really reasonable number for Phish trading,
it might be OK to only do 5 gens; tapes seldom go that far on the net.
But 10 gens really drives the point home, and by 15 it's POUNDING on
your ears.

Dolby B is the only way to fly.


Set the Record Levels for the high gear of your soul!!
Pandion                                       Pandion@Brown.edu
(Lee Silverman)                               ST101137@BROWNVM