[net.audio] followup on pre-echo

fritzz@sdccsu3.UUCP (fritzz the Zebra) (08/28/84)

	A little bit over a week ago I asked the net a question about
	why one can weakly hear a song before it starts on a record. In
	response I got two main answers, both of which I had suspected
	in the first place. One of these reasons is print through on the
	master tape, ie. where the magnetic information on a piece of
	tape rearranges the patterns on the next layer of tape on the
	reel. The other reason cited was called groove echo, in which
	the cutting tool deforms the master disk, and thus pushes the
	modulations over into grooves wich have alredy been cut.
	Responses varied from one end to the other, some stating that
	the problem was due entirely to print through ,and others saying
	that it was entirely groove echo. Then there were some responses
	saying that it could be one or the other depending on
	circumstances, which to me seems to be the most reasonable,
	although I still wonder which is the more prevalent cause.

	Thanks to all who replied.
-- 
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rfg@hound.UUCP (R.GRANTGES) (09/04/84)

[:-)]
I have a moderately extensive classical record library and I quality-
control audition records for one of the well known societies. Whenever
I hear a case of pre-echo, and I've heard a lot of them, I ask it: "Are
you tape print-through or groove interference?"  The answers were running
about two-to-one groove over tape when one day they admitted that they
lie a lot.
  -Dick Grantges   hound!rfg

mikey@trsvax.UUCP (09/07/84)

#R:sdccsu3:-222800:trsvax:55100054:000:621
trsvax!mikey    Sep  7 09:43:00 1984



Time the echo.  If it is exactly one revolution of the record, it is groove
distortion.  If it is not exactly one revolution of the record, it had
to come from somewhere else, presumably tape print thru.

mikey at trsvax


I heard some time ago of a record processor that when cutting a master disk,
would play it twice.  Once to find out where the loud passsages were that
were preceded by quite passages.  This system would then give a slightly
larger gap to the groves at the second tape playing and cutting process
to limit the echo.  I don't know if anyone is using this machine, but it
sounded like a good idea.