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From: ben@moncol.UUCP
Newsgroups: net.audio
Subject: Re: Cassette Head Alignment
Message-ID: <227@moncol.UUCP>
Date: Thu, 28-Mar-85 11:44:18 EST
Article-I.D.: moncol.227
Posted: Thu Mar 28 11:44:18 1985
Date-Received: Fri, 5-Apr-85 07:12:04 EST
References: <161@ucbcad.UUCP>
Organization: Monmouth College, West Long Branch, NJ 07764
Lines: 78


>A while back there was a discussion about cassette decks and head alignment.
>Someone mentioned that Nakamichi was the only manufacturer to align them
>right.  A friend of mine has an older Nak deck that I have used on occasion
>to record albums.  I also have an auto-reverse car cassette deck, which
>works by reversing the direction of the tape and switching its input
>to the other pair of gaps in the head.
>
>What I have noticed, only with the tapes recorded on the Nak, is that
>one play direction always sounds much better than the other.  I have tried
>to align the angle of the car deck's head to sound better (it was definitely
>out of alignment from day 1).  It is easy to do this while the tape is running,
>as there is a cutout that exposes the adjustment screw.  The result
>is that I can never get both directions to sound good.
>
>This implies to me that the Nak deck's head angle is not perfectly perpendicular
>to the tape.  If it were, I would be able to align the car deck's head
>perpendicular to the tape and both directions would sound fine.  This is
>because while recording on the Nak you must physically flip the tape over,
>so any leaning of the record head is reversed on the other side.  The
>...
>This sounds really bad.  This problem does not seem to occur with
>commercially prerecorded tapes, although they are not of the same
>quality as the home-recorded ones and it is difficult to compare.
>
>After all this, what is the problem?  Is the Nak correctly aligned
>and does that mean that auto-reverse decks are no good?  Or does
>it mean that this particular Nak deck is very poorly aligned?
>Or something else?

First of all, I think you misunderstood the recent articles on the Nak
decks.  Nak does not align their heads differently than other
manufacturers, they use a different equalization curve.  As a result,
tapes recorded on a Nak and played on another deck will have noticable
high frequency rolloff.

Second, although it is possible that the Nak has a head alignment
problem, it is almost certain that your auto-reverse deck does.
The problems stems from the cassette itself.  There is almost always
play in the guide rollers that control the tape path:  they tend to
slide to one side of the pin when the deck is playing forwards, and to
the other side when it is playing in reverse.  This kind of azimuth
error would certainly be noticeable, particularly if you use budget
tapes.  Nak is well aware of this problem, they solve it in one of two
interesting ways in their auto-reverse decks.  In the inexpensive
decks, they have motorized cassette drawer that removes the tape and
physically turns it over.  In their more expensive decks (as well as
their car decks), they use NAAC, a computerized system that analyses
azimuth error and uses servo motors to perform a head alignment as you
listen.

                                        Ben Broder
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