Teac TASCAM 32 - Output Select

6) Bias Trap Adjust:
Now is the time to do the bias trap in the record
circuit: with no input signal, adjust test point
TP1 located on the PC Board. Positive side of
the VTVM is connected to the test point,
negative side to ground. Tune inductor L105 for
minimum.
TP1
eee
L105
C131
7) Record Level Adjust:
We give these adjustments just to be accurate
and thorough, and remind you again that they
are seldom needed. Unless you have made some
really drastic change in your recorder, you
should not worry about this adjustment for at
least 6 months.
Again, to be thorough, at this point it would be
wise
to
check
erase
and
bias
again
before
pro-
ceeding. Once you start a major overhaul it might
be necessary to go through these 3 steps — erase,
bias and record level adjustments — 3 or 4 times
before
finally
moving
on
to
the
‘‘record
equaliza-
tion” and then, once more from erase through to
the end. Describing the way is probably giving
the manufacturing setup, or head replacement
sequence when all values of the record circuit
must be re-qualified. If noise is heard, signals
don't erase completely even after adjustment, or
there is not enough rotation of the bias trim pot
left to get a “drop’’ in bias, the whole adjustment
should be considered, but only under these
unusal circumstances.
However, we do recommend that you select a
brand of high quality tape and stick to it. Chang-
ing bias every day for different tapes will make
the recorder cranky and a little harder to adjust.
Constant messing with the controls is unwise
It is a much better idea to do as little as possible
and let the recorder “settle in’ to one kind of tape.
We are now ready to adjust the record circuitry.
We first check the low frequency input level at
400 Hz to get a reference. The steps are as
follows:.
. Adjust oscillator to 400 Hz.
. Select “LINE” on INPUT SELECT buttons.
. Set INPUT and OUTPUT knobs on the front
panel to the “7” position.
.Select “INPUT” on OUTPUT SELECT
buttons.
. Set both FUNCTION buttons to ON.
. Send in 0.316 V, set “O VU" on the 32 meter.
. Record the tone at 15 ips.
. Switch to “REPRO”, read the 32 meter.
.With trim pot #9 R176, 20k ohms (REC
LEVEL), adjust to “O VU”.
With only a few adjustments remaining in the
complete procedure, fet’s review all you have
done up to this point. Step by step, you have:
1. Cleaned and degaussed the tape path.
oS WN
oOOnwo Oo
TP-1 #10 «#9
1105 L104 L103 R176
LOW
45