Path: utzoo!attcan!uunet!midway!linac!uwm.edu!csd4.csd.uwm.edu!info-high-audio-request
From: JFARRINGTON@EAGLE.WESLEYAN.EDU (Jim Farrington)
Newsgroups: rec.audio.high-end
Subject: Tape Squeals
Message-ID: <6869@uwm.edu>
Date: 10 Oct 90 13:07:01 GMT
Sender: news@uwm.edu
Lines: 32
Approved: tjk@csd4.csd.uwm.edu

In reply to Steve Graham's squealing reels, I think I can throw some light
on the subject (though you may not like the answer).  Until the '70s one
of the main components to audio tape was whale oil as it was and is the best
agent for keeping tape supple.  When whaling began to be frowned upon, companies
began to look for new agents to replace the whale oil.  As we are hearing
now, the stuff they began using in the '70s is now disappearing from the
tape which is becoming brittle and "sticky".  The high-pitched squeal you hear 
is actually the tape catching and releasing on the heads many thousands of 
times per second.  Ampex tapes from this time are notoriously bad in this
respect.

Last Formula 9 helps on the heads to reduce friction, but is not the whole
answer.  What you need to do is go to a fabric store and buy some stuff called
"Pellon", a non-woven material used as a backing when making clothes.  Cut
it up to make little patches you can hold between forefinger and thumb. 
The hard part, at least time-consuming-wise, is to sit there and run the
tape through fast forward (not in contact with the heads) while pinching
the tape between the covers of the pellon-patch.  Depending on the severity
of the problem this may need to be done more than once.  This is the only
known way to render the tape playable so as to get one more pass over the
heads and re-recorded.

Jim Farrington
Music Librarian
Wesleyan University                     
JFARRINGTON@WESLEYAN.BITNET
jfarrington@eagle.wesleyan.edu
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