[net.records] Omni-Disk

mat (03/14/83)

(I already attatched part of this to another article.  Sorry for the
duplication)
Telarc released an interesting two-disk set a couple of months ago.
For those of you who aren't into such things, Telarc was the first outfit
with digitally masteed vinyl disks.  To prove a point about the system
they were using, they recorded the 1812 overture with real cannon shots,
demonstrating how much can be packed into a phonograph groove.  Your cartridge
probably can't track it, but that's another question.
The new set is called the OmniDisk and hasthe following:
Side 1:  No music, no test sounds, no groove!  It is an alignment gauge,
	and seems to be pretty good, if you know your tonearms optimum overhang.
If you don't, you will need to use a gauge that relies on a line through the
pivot point.
Side 2:  Various bands with wideband and band-limited pink noise, as well
as tracking tests.  For example, how do you REALLY check the anti-skating
force? Telarc's answer is to provide a band that becomes incrementally harder
to track.  It is a mixture of two frequencies near 1000z, and sounds awful,
but mistracking is VERY audible.  If one channel mistracks before the other,
your anti--skating force is off.  There are also bands with swept and pulsed
sine waves, and out-of-phase pink noise.  About the only thing it won't
check is how well the turntable matches the room's color scheme.
Except for a couple of equalization tests, no test gear is needed.  Certainly
all of the important ones that bear on record wear are covered with no gear
at all.
Side 3:  There are five short excerpts from Telarc recordings, all known
to be difficult to track, and each repeated 4 times, stepping up 2 dB each
time.  Yes, the cannon shots are there.  If you can track those, your system
is a real winner!
Side 4:  You've read this far.  This is the payoff.  Side four has got
two bands, separated by a stop groove.  Band one is a modified version
of Britten's ``Young Person's Guide to the Orchestra'', with the conductor
clearly announcing each of the instrumental groups as they play seperately.
A diagram and Photo of the orchestra layout are provided so that you can check
the imaging.  The second cut is a remake of the Beach Boy's ``Good Vibrations''.
This is woth the price of the whole OmniDisk set.  Played on a reasonable
system with plenty of reserve, it WILL blow you away. The immaging, dynamics,
and frequency range (OH THAT BASS) are better than anything I have heard
anywhere else. Play this one quietly the first time, or you may have
to go to Volgagrad to find the voice coils from your woofers.
Oddly enough, this is possibly the first ``mixdown'' cut that Telarc has done,
and the realism is greater than with most digitally mastered audio
disks that I have heard.

One last observation:  It should be obvious from the two cuts on side four
that even on conventional vinyl, the skill and determination of the recording
and mastering teams are the most critical parts of making a great recording
(I'm talking about the RECORDING, not the performance it records)  This is
the bottleneck in producing extraordinary recordings.  Will the DCD address this?
I suspect not.  We will still be buying many recordings with inferior sonic
qualities; in fact, I suspect that most of our recordings will be about
the same as they are now, except that there will be no surface noise and
better dynamic range on a good deck.  If the DCD disks are going to
cost over $15, there ought to be something given in return.  I am afraid that
it will be the word ``digital'' on the disk, and not much more.
Oh, weel, they call that Marketing.

Buy the set.  It is great.
					Duke of Denet
					Merk Terribile

jeff (03/15/83)

Yes but WHERE on the disc is the anti-skate measured?  Unless the anti-skate
arises from a magnet or a counterweight (e.g., SME) it will differ at
different radii.

kar (03/17/83)

	We've heard that the OmniDisk has the cannon shots on it from the 1812
that Telarc recorded.  I bought the 1812 record a couple of years ago, and it
is fantastic.  This is the first recording of the piece I have heard in which
the cannons do not sound like someone beating on garbage cans with baseball
bats.  I played the record for my father and his unconcious reaction to the
first cannon shot was to duck.  It is that realistic.

	It is rather difficult to track, however.  At slightly more than the
maximum recommended tracking force, I can still hear the stylus bouncing around
in the groove on the last shot, and the tone arm itself moves visibly.

	The best part, however, is the carillon.  It's hard to describe.