Layman's guide to playback azimuth adjustment
ccrider
In response to many azimuth questions and allusions,
I composed this rather generic document describing the methods I've
used to
set playback azimuth on decks I've used for playback in the past.
I've done this with great success on both 2 and 3 head decks,
and more specifically, on an AIWA AD-F810, AIWA AD-F850,
some old Pioneer 2 head I had at one point, multiple Kenwood, Fisher,
Sony,
and Onkyo dubbing decks, and others.
The following method certainly has a way of bringing out the best in
tapes made
in decks other than my current record deck. Your mileage may vary.
Tapes made in the head-flipping autoreverse type decks are typically
most
in need of an azimuth adjustment, although anything can happen over
time
to even the best Naks.
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DISCLAIMER:
If you fuck your decks up doing this, it's not now,
nor will it ever be, my problem. Those who are either technically
inept
or unwilling to accept responsibility for their actions should
probably
seek professional help of some kind(technical, psychological,
sociological,
horticultural, pharmaceutical, whatever...)
----------------------------------
Now that that's said... here's the layman's guide to playback azimuth
adjustment
when there's no actual knob or feature.
The azimuth adjust screw is typically located just to the left along
side of the playback head.
On a regular, standard 2 head tape deck(and many 3 head decks),
that screw has a spring behind it.
I don't know the layout of some of the more exotic Nak's head
assemblies
but if it's anything like any standard 2 head tape deck,
then that's exactly where you'd find that screw.
Note: You will probably have to remove the faceplate on the door in
order
to gain easy access to the head screws. If your deck doesn't
have
a removable door, then you're probably going to find it
difficult to
get access to the screw in question. Sometimes there's also a
little
hole in the faceplate of the deck that lines up with the screw
when
the head assembly is engaged during playback.
There is usually a bit of enamel or glue painted on that screw to
prevent it
from turning during regular usage. Cracking that seal may cause the
screw to
turn ever so slightly on it's own when the head assembly
engages/disengages
in normal operation... Not to mention the fact that it may void your
warranty. The screw(with the spring behind it) may be tight and
generally prevent it from slipping out most of the time... or it
could
be a bit looser, causing it to slip out more frequently.
I have done this on both types of azimuth screws(tight and loose),
and I haven't found this fact to be much of a problem during tape
play.
In other words, once it's set, it shouldn't slip out during that side
of
the tape anyway. You may notice it slipping out after repeated full
stops
and starts of the tape, where the head assembly is
engaging/disengaging.
It all really depends on how "clunky" the assembly engages(if
it's smooth you probably won't knock it out as easily),
and how tight the screw is.
In any case, you should know that once you break that seal, you
really should
make it a habit to set the playback azimuth for every tape side you
ever play
in it again.
It's not really that big of a deal... once you've done it a few
times, it's
second nature, and should only take a couple of seconds to adjust.
You'll probably need a fairly small Phillips-head
screwdriver(I recommend buying a jeweler's screwdriver set for this
from Radio Shack).
The trick is to accentuate or exaggerate the high frequencies, and
cut the mids and lows
down all the way. Keep the balance in the center. I have a dual
channel, 10 band
EQ/analyzer(NOT in the recording loop), and I put all the freqs all
the
way down except for the highest 2 or 3 freqs. Then, I turn up the
treble on my receiver to boot. This makes the highs extremely
exaggerated, but
also makes it very easy to tell whether you got all the highs your
going
to get or not(be careful to turn the volume down some so that you
don't blow
your tweeters or ears for that matter). If the tape in question
requires Dolby
for proper decoding, performing the azimuth adjustment with Dolby
turned OFF may
make it easier.
Engage the heads and turn the playback azimuth screw back and forth
and you'll hear the highs come in and out(left and right as well).
Basically(and unfortunately), but interestingly enough,
the point at which the azimuth is properly aligned is typically the
point
where the high-end hiss is most clear and defined in BOTH channels.
Which
reminds me... you must have your room laid out in an acoustically
correct
manner, with the speakers equidistant(both horizontally and
vertically) from where
you stand(in front of your deck). If your system is not arranged
such that
your decks are in the center between the speakers,
then you're going to have a tough time. In any case, slowly turn the
screw
back and forth in ever decreasing sweeps or arcs until you find it's
at it's
optimum position. It shouldn't take more than half a turn in either
direction to
produce the desired results. When the highs are as good as it gets,
then it's set as good as it's gonna be for that tape(very profound
statement... I know, I know....). Take great care not to apply too
much pressure
to the screwdriver, as you may bend or otherwise damage the head
assembly.
Also, make sure you don't have a TV, CRT, computer monitor, etc.
anywhere in the
same room as your decks, as this will induce high-end noise or whine
into the decks,
and prevent you from making good judgement. This is a general rule
for taping
anyway, but unfortunately, most people are not aware of the
horrible(IMHO) noise
that TV's induce into their recordings. It always seems like good
logic to
have the TV and the stereo all right near each other so you can hook
the VCR,
TV, and all that stuff up. Too bad that logic has ruined many a
tape.
Tapes are better than TV, and you should be monitoring your recording
anyway,
so turn the damn thing off and listen to the tunes instead! OK,
enough about that...
It's a given that you should have good, well balanced hearing, with
good
high frequency response(16Khz-22Khz).... or a stereo oscilloscope...
;)
After playing with it on several tapes, you start to know what to
look for
right away. Sometimes though, it still takes some effort to focus
your
hearing on the highest of the highs. It only takes 2 or 3 hundredths
of a degree
in azimuth to make the difference between clipping everything above
15Khz to
bringing the full spectrum into "focus." This translates into
extremely small
increments in change of the screw. With a little bit of practice,
and sometimes
a lot of patience, you'll feel like you know what you're doing.
To get the head realigned to something resembling factory
reference(maybe you then want to use the deck not for playback,
but for record sometime), you could do one of two things.
You could tune the azimuth to a store-bought, prerecorded tape with
lots of clear
and dynamic highs(something with lots of hi-hats and other cymbals),
or you
can make your own reference tape(preferably on Metal bias tape, with
no
Dolby, and before cracking the enamel on the screw) from a dynamic
digital
source(preferably all digital) with lots of clear, crisp highs.
As long as you always use the same reference tape,
all the recordings you make should be consistent. However, as long
as the head
is not so misaligned that the tape doesn't completely cover it, the
recording
you make with it should be able to be "refocused" on playback with
an
adjustment to the azimuth.
I make it a personal rule never to touch the playback azimuth on my 3
head
record deck, so it remains as consistent as possible. It also helps
to write
the name of the record deck used on the J-card of a given tape to
keep
track of your different alignments over the years. It helps to be
able to
determine whether or not a tape can be properly played on another
deck without
adjustment.
*** Note of caution: I know of many Naks which don't have the same
head
assembly/transport layout as most cheaper/other decks. The screw is
typically
more accessible on these decks, but in a different place. Any plain
old
cheap-o, non-Nak deck should have the screw located to the left of
the head.
I have never personally seen the azimuth screw on the right side of a
non-autoreverse
head(the flipping around kind found in many auto-reverse dubbing
decks).
The screw to the right on a non-autoreverse head is typically the
stationary
head mounting screw, and SHOULD NOT BE TOUCHED! Decks that have
auto-reverse
with the head that flips around 180 degrees will usually have two
screws on
the barrel inside which the head sits. The other end of the screws
typically
acts as a stopper for the heads when they do their 180 degree flip.
If you
turn the screw on the left side when the head is in the forward
direction,
this will change the playback azimuth for the forward direction.
Likewise, the
screw on the right side will affect the head when it's flipped in the
reverse
direction. If your deck has the type of auto-reverse where the
playback head
is stationary(with four actual heads on the playback head, 2
capstans, and
alternating pinch rollers), then I'm not sure you should be trying to
do
anything with the head alignment.
If you find any of this useful, or you have anything to add or
question, please
lemme know.
Good luck, and dub on!
-Dan
____________________________________________________________________________________
/ / \ \ \ \ \ \ \ \ Finger me for my aging
Dead List
\ \ \___/ \ \ \ \___ \___/ as of May '95...
\ \ \ \ \ \ \ \ \ \ "In the land of the
night, the ship of
\___\___ \ \ __\__ \___/ \____ \ \ the sun is drawn by the
Grateful Dead."
-ccr...@access.digex.net
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