Teac A-3440 - Monitor Performance Adj.-1; Line Input Level Adjust; Mic Circuit Function Check; Output Amp. Gain Adj.

8-MONITOR PERFORMANCE ADJ.-1
8-1 LINE INPUT LEVEL ADJUST
—
N
wW
wk
OUTPUT SELECT SW........ SOURCE
INPUTSW ................. LINE
INPUT VR .............. Maximum
. Remove the special shorting connector joining ENCODER
SEND and ENCODER RCV jack 1 (Channel 1).
Connect a VTVM to the ENCODER SEND jack 1.
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T1280
Fig. 8-2 Shorting Connector
Apply a 400 Hz —22 dB (61.5 mV) signal from an AF
oscillator to LINE IN jack 1.
. Adjust the SOURCE CAL. VR194 for —8 dB (308 mV)
at ENCODER SEND jack 1.
NOTE: This is the Minimum Input Level
Change the input signal to —12 dB (195 mV).
. Adjust INPUT level control for —8 dB (308 mV) at the
ENCODER SEND jack 1.
NOTE: This setting represents the Specified Input Level
OSCILLOSCOPE
AMP SPKR
=
AC Voltmeter
OSCILLATOR
ENCODER
SEND
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T~1367
Fig. 8-3 Test Connections for Monitor Check
8-2. MIC CIRCUIT FUNCTION CHECK
6
7
8
INPUT SW .... MIC (ATT =0 dB)
. Apply a 400 Hz signal at —60 dB +2 dB (975 uV
615 uV) to the MIC input jack (on front panel).
. Check for —8 dB (308 mV) at ENCODER SEND jack 1.
INPUT SW ....MIC (ATT = 20 dB)
. Check for an output 20 dB +1 dB below the 308 mV
output obtained in steps 6 and 7 above. (ie. Output
should now be — 28 dB or 30.8 mV)
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8-3. OUTPUT AMP. GAIN ADJ.
9.
10.
11.
12.
13.
14.
Be sure the control are set as in 8-1 (Specified Input
Level Setting).
Insert shorting connector between ENCODER SEND and
RCV jacks.
Connect a VTVM to the OUTPUT jack 1.
Set the OUTPUT Level ‘Control to position “8”. This is
the Specified Output Setting.
Apply a 400 Hz —12 dB (195 mV) signal from the oscil-
lator to LINE IN jack 1.
Adjust OUTPUT CAL R149 for —8 dB (308 mV) at
OUTPUT jack 1.
84 VU METER CALIBRATION
15.
Adjust METER CAL R159 for 0 VU reading on the VU
METER.
NOTE: Repeat the above procedures for channels 2, 3 and
4,
9-PLAYBACK PERFORMANCE ADJ.
9-1 PLAYBACK HEAD AZIMUTH ADJ.
NOTE: Before proceeding with the following head adjust-
ments be sure that the heads have been properly
mounted for HEIGHT, TILT and TANGENCY.
See page 10.
OSCILLOSCOPE
DECK
under TEST
T~813
Fig. 8-4 Head Alignment Fine Adjustment Set-up and
Test Connections (PLAYBACK)
OUTPUT
SELECT
SW..........
PLAY
.
Connect
a
VTVM
to
the
OUTPUT
jack
1.
.
Remove
the
head
housing
by
removing
the
2
retaining
SCTews.
.
Thread
a
TEAC
YTT-1003
Test
Tape
on
the
deck.
.
Play
(bm)
the
16
kHz
—10
dB
test
tone
from
section
2
of the test tape.
.
Slowly
rotate
the
Azimuth
screw
until
the
maximum
signal is read on the VTVM.
6. Connect an oscilloscope to the OUTPUT jack 1 and 3.
7.
Adjust
the
Azimuth
screw
if
necessary
until
the
following
phase
difference
figures
are
obtained.
See
next
page.
17
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