Tascam 388 Studio 8 - Recorder;Reproducer Section Adjustment; Recording Blas Adjustment; Reproduce Frequency Response; Reproduce Level

1-5. RECORDER/REPRODUCER SECTION
ADJUSTMENT
1-6-1. Reproduce Level
1) Connect a level meter to the TAPE OUT "1"
jack on the rear panel.
2) Reproduce a TEAC test tape YTT-1003,
400 Hz and adjust the trim pot R128 for
-12.6 dB (230 mV) readingon the level meter.
(If you use Reference Fluxivity 250 nWb/m
tape, adjust the trim for -10 dB reading.)
3) Connect the level meter to the remaining
channel outputs (2 to 8) and proceed to the
adjustment in the same manner by adjusting.
R128: for channel 1, 2, 5, 6
R228: for channel 3, 4,1, 8
OSCILLOSCOPE
OSCILLATOR
9 o
AMP SPKR
ATTENUATOR
r n iNPuT
UNIT
under TEST
AC VOLTMETER
OUTPUT
IvH
o o
1-5-1. Reproduce Level Caiibration
1-5-2. Reproduce Frequency Response
1) Connect a level meter to the TAPE OUT "1"
jack on the rear panel.
2) Reproduce a test tape YTT-1003 and reads
the output level; it should be within the
following limits.
3) If the output level is out of the limits, adjust
the trim pot R124.
4) For the remaining channeis (2 to 8), aiso
proceed the check and adjustment in the same
manner.
R124: channeM, 2, 5, 6
R224: channel 3,4, 7, 8
( OBI
+ 6
+ 4
+ 2 H
o
-2 -
Fig. 1-5-2. Reproduce Frequency Response
1-6-3. Bias Tuning and Bias Trap
These adjustments have necessarv
factory and realignment will ^
except for the following circurnstanc . . .
♦ When the REC/REPRO head ERASE head
and/or Bias amplifier is replaced. , .
* When the MASTER BIAS unit is repiacea.
Use the following procedures to adjus
A.BIAS TUNING u
1. Place all channel REC FUNCTION switches
to ON and set the tape deck mto the RE-
CORD mode. -i-oi-.-
2. Connect a DO volt-meter between TPOI
(TP02, TP03, TP04) and TP11 '^.13.
TP14) by using an insólate n®""'
L101 (L201, L301, L401) on the BIAS PCB
(1) and BIAS PCB (2) to obtain a mínimum
reading on the DC meter. Be sure to use a
non-conductive screwdriver (i.e. wood, plástic,
etc.).
CAUTION: Do not try to obtain máximum
reading on the DC volt-meter,
which would occasion an extreme
amount of Bias Amp output load.
B BIAS TRAP
1. Connect an "AC" level meter between TP1
and ground on the REC/PLAY AMP PCB.
2. Place all the REC FUNCTION switches to
ON and set the deck into the RECORD
mode.
3. Adjust L104/L204 to obtain a minimum
reading on the level meter.
1-5-4. Record ing Bias Adjustment
1) Connect AC Voltmeter between TP 2 and TPG
ón the REC/PLAY AMP PCB.
2) Adjust trim pots on the BIAS PCB for a
120 mV reading on the AC Voltmeter.
Trim pots to be adjusted:
C103
C203
C303
C403
channel 1, 5
channel 2, 6
channel 3, 7
channel 4, 8
after
1-5-5. Record ing Level
This alignment should be performed
completion of the bias adjustment.
1) Connect test equipment as shown in Fig. 1 -5-1.
Connect an AF signal generator to PGM BUSS
IN jacks.
Connect level meters to both TAPE OUT and
PGM OUT jacks.
(If two meters are not available, use one
meter alternately.)
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