Teac X-1000 - 3-5-1 Encoder Adjustment

|
X1000M/X1000
3-5-1
ENCODER
ADJUSTMENT
Connector's pin 1 and pin S
correspond to L-ch and R-ch.
AC VOLTMETER
Low
distortion
~
DBX
PC
ee
OSCILLOSCOPE
AF
OSCILLATOR
8903:
EA
cal
ATTENUATOR
Pres)
4
_
4
a
P701-1(5)
GND
GND
Distortion factor: 0.02% or less
Max.
output
level:
3V
or
more
‘j
Fig. 3-11 Encoder adjustment setup
This terminai is not the same
as the encoder and decoder
terminal (See Fig. 3-14).
U501-2 is not used.
Level variation:
5mV or less OSCILLOSCOPE
DBX PCB
TP.3(TP.4) (5)4
Y scorer DEFLECTION
WAVEFORME
Do not ground these
GND terminals.
v
4180mV
t
-180mV 7
SYMMETRY ADJUSTMENT WAVEFORM
VCA SYMMETRY ADJUSTMENT
WAVEFORM GENERATOR
Fig.
3-12
VCA
symmetry
adjustment
setup
(encoder)
MEASURING POINT:
ADJUST
{TEM
INPUT
INSTRUCTION
(or
CHECK)
RESULT
.
Preparation
Prepare
test
setup
as
shown
on
Fig.
3-11.
Preset
each
of
the
trimmers
of
the
encoder
section
on
the
PCB
to
their
approximate
center
teens
_
positions.
.
Input
setting
:
Apply
100Hz
level
to
get
RESULT
j
Attenuator
P702-1(5):
|
value,
300mV
(—-8.2dB)
.
RMS
symmetry
R765/R766
|
TP3(TP4):
Refer
to
Figs.
3-9
and
Clean
200Hz
sine-wave
3-10.
:
.
RMS
time
/
Check
TP3(TP4):
constant
385uV
(—66.1dB)
+20%
.
Encoder
nominal
Apply
1kHz
level
to
get
RESULT
Attenuator
P702-1(5):
level
value,
300mvV
(—8.2dB)
R737/R738
|
P703-1(5):
*4
300mV
(—8.2dB)"1
|__
Reference
1
|
.
VCA
symmetry
Change
test
setup
to
as
Fig.
3-12,
R757/R758
|
P703-1(5):
then
adjust.
:
A
relatively
straight
hori-
zontal
line
on
the
‘scope
face’.
(Level
variation:
5mV
or
less)
15