* The various Test Modes are initiated by pressing
these buttons during the Power-Up sequence.
** Press STOP immediately after the machine is powered
up.
The alpha-numeric display should indicate "test,"
if
so, proceed to next keystroke.
# SY-88 sync card will not operate properly with system versions below
3.01. Contact Tascam if version 1.03 is found.
Do not remove the WORD SYNC screw. The back panel improves the ground
connection and minimizes noise.
! After installing new firmware, a "First Birthday" is required to initialize
the system.
Set all S1 dip switches to ON, power up for three seconds, power down
and set all S1 dip switches to the OFF position.
ABOUT ERROR RATE
Some manuafacturers are reluctant to allow users to access error information
an essential feature that provides useful feedback. I encourage users to
"provide useful feedback" to the Manufacturers by telling them how important
easy-access error indication is.
WARRANTY COVERAGE
Tascam's DA-88 warranty is currently 90 days for labor and one year
for parts. In the first year of its release, Alesis sent a warranty upgrade
to all of its ADAT XT customers. Now increased to 1 year parts and labor,
it was formerly 90 days for labor/head assembly and one year "free of defects."
The XT headstack is warranted for 1 year or 1500 hours. Tascam's expected
head life is 1000 hours.
TAPE RECOMMENDATIONS
In the Fall of ‘96, at a SPARS meeting — The Society of Professional
Audio Recording Studios — a representative from BASF made a presentation
on the subject of recording tape and its relationship with head wear. While
I briefly touched on this subject in the October’96 EQ, these points need
to be stated:
-
All tapes have a built-in abrasive "component" that is designed to help
keep heads clean "while you work." If tapes were completely non-abrasive,
the heads would clog and you’d get nothing done.
-
Major wear occurs during the first half of a head’s expected life. This
is normal. Just as an auto engine has a break-in period, it takes a while
for the head’s contour to precisely match that of the tape’s path. And,
if you didn’t know, tapes differ in degree of stiffness and this alters
the "path" taken.
-
High humidity, smoke (from cigarettes, etc.) and dust (from sheet rock
or whatever) increase abrasiveness and decrease head life. No figures were
given, but 40% humidity is a good reference point. The opposite extreme
increases the potential for dangerous static electricity. My shop is currently
at 79 degrees and 22% humidity — the latter a 50% drop from summer’s end
— and now, without air conditioning. Any less moisture and a humidifier
will be necessary.
-
Just as dog food can be optimized for the age of your pet, certain types
of tape may be better for heads as they wear. If you stick with one brand
for a long time, a change might yield either an improvement or a degradation.
All politics aside, it really is hard to recommend the "best" tape because
so many factors contribute to performance. Always check the error rate
to be sure.
DTRS: DO YOU KNOW WHAT IT MEANS?
DTRS (Digital Tape Recording System) is the official name for the Hi-8
digital eight-track format used by Tascam in models DA-38 and DA-88 as
well as their made-for-Sony PCM-800. During a repair class in October,
I learned about Tascam’s intensive search for the ultimate DTRS compatible
tape and was given both Sony DARS-60MP and BASF tapes for evaluation. They
seem quite good. Look for the DTRS logo on other brands of tape as well.
( A spot check at a local store in my neighborhood yielded three lengths
of Ampex DA8, DTRS certified stock.) Stay away from
DIC tape ! ! !
HOW TO BREAK-IN NEW
HEADS
Some "young" DA-88 heads can be very sharp and, under certain conditions,
tend to "grab" the tape. Those "certain" conditions occur when tension
is applied to the tape before the head is spinning or fully up to speed.
This, in my opinion, is a software problem that is exacerbated when heads
are manually cleaned or with certain batches of tape. You must allow
time for the alcohol to dry!!! Whether the heads
are sharp or damp, either condition may cause the tape to stall and/orwrap
around the rotary head. One example of this would be to attempt to format
a tape from the middle of it's length. This is also a combined idiosyncrasy
of weather, its affect on (and variations of) tape formulation.
For all machines, it is highly recommended that users take advantage
of new heads by formatting at least a "box" of tapes (typically 10). It
is common practice at video studios to record "black" across an entire
length of tape well in advance of any targeted use. Formatting tapes, from
beginning to end, minimizes the intermittent starts and stops that can
aggravate "stiction" between heads and tape. Not only is it a great way
to break-in new heads, it also makes better pre-formatted tapes.
Once a DA-88 displays an error message, the transport will neither function
nor eject a tape. This safeguard protects the tape from damage. Do
not attempt to manually remove the tape. At the first sign of
trouble, TURN THE MACHINE OFF. Power-up by simultaneously pressing
FF, STOP and PLAY, then press STOP. You have successfully entered "TEST"
mode if the display momentarily indicates "TEST." If not, try again. (
By entering TEST mode, you are more likely to be able to safely eject a
tape.) Once TEST appears, wait for the TASCAM (or user-customized)
banner to be displayed on the meters, then press EJECT. Do not attempt
to do anything else while in TEST mode. Power down after the tape is ejected.
Do your own trouble-shooting
If the problem persists, change the brand or batch of tape. All tapes
with the DTRS logo (Sony, AMPEX and
BASF
that I know of) work very well and are very similar. (hint! hint!)
Maxell tapes, especially their "Broadcast" series, have been successfully
used by Record Plant Remote. Metal Particle (MP) tapes are recommended
for situations requiring heavy shuttling. Metal Evaporated (ME) tapes yield
better RF output and lower error rates. HOWEVER,
"ME" tapes do not
behave well under stress and so should only be used for archiving and long-form
projects. Both Fuji and TDK 8mm tapes may not work well on
your DTRS machine, although a good technician can optimize the record current
and ATF (playback) so that these tapes can be used. As an "insurance
policy," always check the error rate after formatting a tape. Here's
why...
TAPE: VARIATIONS ON A THEME
We are all familiar with the sonic differences of various analog cassette
tapes. Distortion, bass and treble response all vary with tape formulation
and thickness. Variations are corrected via record current (bias) and EQ
adjustments, but cassette decks can never be optimized as easily or as
well as professional open-reel equipment. Optimizing tape performance
for DAT, Adat and DTRS is another story...
The goal for digital and analog tapes is similar: minimum drop-outs
(error rate) and maximum signal strength (output level). Weak signals in
the analog world result in hiss, while digital tapes are recorded at saturation
(maximum) and, if the signal falls below the threshold of recoverability,
that familiar mashing, digital chain saw sound will result.
Another fact about saturation recording is that no erase head is required.
The new signal simply blasts away the old! While a single analog head can
send or retrieve tape signals, a pair of heads are required in the digital
domain (both pairs for overdubs). The pairs are fairly well matched when
new — one head could almost do the job if absolutely no errors are encountered.
Since this is an impossibility over time, a single clogged or worn head
will send the error rate into orbit.
TRACKING: OBSTACLES TO QUICK LOCK-UPS
In addition to digital audio information, both DAT and DTRS embed Automatic
Tracking Frequencies (ATF) within the usable helical recording space. (The
Adat system uses a linear control track for this purpose.) DTRS uses four
repeating tracking signals whose frequencies are between 100 kHz and 200
kHz. This is low frequency information when compared to the region between
3.15 Mhz and 6.3 Mhz where digital information is encoded.
For DTRS, slow, multiple-machine lockups can be a sign that the tracking
signals are too hard to read. Across-the-board tracking problems for all
machines — including DAT and Adat — are mostly mechanically related. Poor
tape-path and out-of-spec supply or take-up tension can also contribute
to a sluggish transport.
SWABBING THE DECK
There are many opinions about head cleaning...
Follow this link for more information
-- and pictures too ! ! !
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Eddie
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