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From: mwilliams@mahler.DEC (Mike Williams 229-6258 LTN1-2/B17)
Newsgroups: net.audio
Subject: Cassettes / Audio Amatuer
Message-ID: <1477@decwrl.UUCP>
Date: Wed, 3-Apr-85 13:38:10 EST
Article-I.D.: decwrl.1477
Posted: Wed Apr  3 13:38:10 1985
Date-Received: Thu, 4-Apr-85 08:08:06 EST
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Subjects:	Cassette durability query
		Audio Amateur query


  For 6 or so years, I have been using TDK SA cassettes in my BIC T3. A good 
number of these were also used in a car deck (Jensen RE505?) which I no longer 
have. I have been experiencing regular failures of my older/more-frequently-
listened-to tapes. There are two failure modes. One is that over time, the 
tape does not wind uniformly (w.r.t. position) on the internal spools. That is,
the edge of the tape which is at radius r from the spool is not in the same 
plane as the edge of the tape which is at radius R. Obviously, as this 
progresses, the tape edges contact the case increasing the effort required to
pull the tape out causing tape stretching or tripping the mechanical end of 
tape detector. 

The other failure mode is not as gradual. The tape does a 90 deg barrel roll
inserting its edge into the seam of the case. From this key starting point, 
a whole host of wonderful things can happen, the worst of which is that a 
crisp seam forms along the length of the tape. This failure occurs most 
commonly in tapes that are in early-stage type 2 failures. 

I suspect that the fault is in the media, more than the tape drive. I never
have problems with new tapes, and this only occurs in my cassettes that have 
many hours of play time, or that are among the older ones. Given that I'd
rather stick a needle in my eye than onto one of my records (I tape the first
time I play), and that the record cleaning ceremony I go through would put many 
semiconductor foundries to shame, I would like to get as many miles out of 
a tape as possible. My questions to the net are:

	1. Would anyone care to venture an EDUCATED guess as to what is
	   happening?

	2. Is this a common problem with the TDK SA?

	3. Are my expectations for tape longevity too high?

	4. Is there a tape made that has a reputation for longevity AND
	   acoustic quality? (What's Maxell's rep?)

	5. My principal suspicion is tape case warpage. Does this vary
	   with case construction (glued vs. screwed vs. both)? If so,
	   which has the best chances of outliving the others?

Anticipating some responses:

	I do plan to get into CD, but a lot of what's in my record library
	won't be available for a long time, if at all.

	These problems have spanned several tape alignments (which were
	done at different shops).


I've also seen references to The Audio Amateur in various discussions. Would
somebody please post some relevant subscription info - $$$, address, typical
content.

Thanks in advance,

Mike Williams

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