brent@itm.UUCP (Brent) (03/29/84)
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cassettes - part 6
On now to loop-bin duplication. We'll look at three manufacturers:
Gauss, Electro-Sound, and Magnefax. First the best: Gauss
Gauss uses a horizontal loop-bin. That is the two plates of
glass that the master tape squiggles in between are parallel to the
floor. It looks sorta like a continuous cloth ribbon for a NEC spinwriter.
The tape is pulled out of one end of the bin, passed over the play head,
and gets pushed into the other end. Usually they use 1" tape for masters.
The top-end machine moves the master tape at up to 240 ips. The signal
from this machine gets passed along to up to 10 slave units. These look
like traditional horizontal-mount reel-to-reel decks, except they use
bulk reels of cassette tape (known as "pancakes" for obvious reasons)
The cassette tape can move at up to 240 ips as well. Now, if you're
clever, you see that with the cassette tape moving at the same speed at
the master tape, you have to record the master tape at the same speed
as cassette playback: 1 7/8 ips. Now try to find a reel-to-reel deck
that will record half-track mono or quarter-track stereo on 1" tape
at 1 7/8 ips. Hint: only Studer will build such a beast, and they
are high. It seems the final quality of the cassettes produced by this
process are limited only by the master tape. As you can imagine
at 1 7/8 ips on 1" tape in half-track mono, tape head alignment is
super critical.
At lower speeds, say slaves at 60 ips and master a 120, on good
quality tape (Agfa PE 611) I am told the quality of the cassettes from
Gauss equipment is so close to the master tape, it's frightening. The
nearest commercial Gauss installation to me is in Nashville. I have
seen the Gauss demoed at the trade shows, but have never been to an
actual dup house using them. I am told they are real woolyboogers
to keep running right.
Cost: High. Loop-Bin master unit: $40,000, each slave $20,000.
So a three position dup set-up will cost $100,000 for the Gauss, not
counting the King 790s: you'll probably need 2 at $26,000 each, not
counting the Studer deck, 1/4" master deck, etc, etc. Now you know
why they run them at 240 ips: to make them pay for themselves.
Next time: the machines most people use.
--
Brent Laminack (akgua!itm!brent)