Teac V-909RX - Input Signal

V-909RX/V-707RX/V-707R
65.5
DBX
PCB
ADJUSTMENT
(V-909RX/V-707RX)
Note:
:
;
Since the DBX PCB assembly has been precisely adjusted at the
factory,
this
adjustment
is
not
usually
needed
unless
any
of
the
trimmers
have
been
changed,
or
any
components
on
the
PCB
have
sustained damage.
5-6-1 PREPARATION
1. Disconnect the wires from the P10 connectors on the DBX PCB.
Turn the deck OFF to prevent accidental damage when dis-
connecting or reconnecting.
5-6-2 ENCODING ADJUSTMET
SETTING
INPUT SIGNAL
2. Make the following initial settings.
e POWER switch: ON (for supplying power via the P11 connector
to the DBX PCB).
NR system switch: OUT
DBX PCB trimmers: Approximate center positions
All other front panel switches and controls have no effect
on this adjustment.
Check in the REC/PAUSE mode.
ADJUST
(or CHECK) RESULT
REMARKS
100 Hz/—8.2 dB
(300 mV)
1. RMS SYM
Clean 200 Hz sine- Refer to Figs.
R53/R63
wave.
5-7
and
5-8.
2. Encoding level (300 mV)
3, VCASYM
100 Hz/—8.2 dB
4.
Encoding
single
(300
mV)
frequency re-
sponse 10 kHz/—8.2 dB
(300 mV)
400 Hz/—68.2 dB*3
(300 uV)
5. Encoding opera-
400 Hz/—8.2 dB*!
«1
R52/R62 8.2 dB*? (300mv) | ia Reperence F
TP.52/TP.62: Arelatively straight horizontal
line on the scope face.
(Level variation: 5 mV or less)
R51/R61
+0.2 dB £0.5 dB against
Ref.2
(290 mV ~ 325 mV)
~—3.3 dB +0.5 dB against
Ref. 2:
(194 mV ~ 217 mV)
~—30 dB +0.5 dB against
Ref.2
(8.96 mV ~ 10.1 mV)
*3 60 dB
against Ref. 1
tion level
400 Hz/+11.8.dB*4
(3.00 V)
+10 dB +0.5 dB against
Ref. 2 *4 +20 dB
(0.896 V ~ 1.01 V) tae Ref.1
Distortion: 0.3% or less
Low distortion
AF OSCILLATOR
Distortion: 0.02% or less
Output: 3 V or more
Distortion: 0.02% or less
Output: 3 V or more
Fig.
5-8
RMS
SYM
check
(Incorrect)
ea np
OSCILLOSCOPE
DBX PCB AC VOLTMETER
P11:CONNECTED ,
H
ATTENUATOR TP53 (TPE3)O eye
° 3 o——? TP51 (TP61) Gee
a TLO@@ J tit P10-29
7
A
FRI
Fig. 5-9
AC VOLTMETER
OSCILLOSCOPE
Low distortion
AF OSCILLATOR DBX PCB
(s) P14 :CONNECTED |
'
ATTENUATOR
TP52
(TP63)
@@®@®
©
OLE
@
@
@
3
yTPs1
(TP61)
0.9
O@O@®
EXT.
TRIG.
(AR)
22
Fig. 5-10