Checks - Yamaha SPX50D Service Manual

SPX50D
CHECKS
1
.
PREPARATIONS
1
-1
Preparatory Settings
•
Unless otherwise specified,
the
volume
on
the
front panel
and switches
on the
rear
panel are to
be
set
as follows:
INPUT VOL.
MAX
SW
101,
102
"T"
• Each
load of the
OUTPUT
L
and R conm-
ector
is
to
be
serially
connected
to a load
resistor
(lOkohms)
•
After inspection, set
switches
SW101
and
1
02
to
"N".
1
-2
Measuring Instruments
• For the
distortion
measurement,
a
low-
pass
filter
with cut-off
frequency
of
80
kHz and
—
6dB/0CT must
be used.
.
•
For the noise
level
measurement,
a
low-
pass
filter
with the cut-off
frequency
of
12.7kHz and
—
6dB/0CT must
be used.
• The
output
impedance
of the
AF
signal
generator
must
be
less
than
600
ohms.
• The
input
impedance
of
the
measuring
instruments
must
be over
1
Mohms.
2.
INSPECTIONS
2-1 Gain
When
a
input
signal of
—
1
6.0dBm
at
1
kHz
is
applied to
the
INPUT
connector,
output signals of
—
6.0
±1
dBm
will
be
obtained
at
the
OUTPUT
L
and R conne-
ctors.
2-2 Frequency Characteristics
When
an input signal of
-30dBm
is
ap-
plied
from the
INPUT
connector, the
fre-
quency characteristics of the
OUTPUT
L
and R connectors are within
the range
listed
in
the table
below.
The
reference
frequency used
is
1
kHz.
1
—
1
^
fii
INPUT VOL.
MAX
SW
10
1,102
"T" (TEST)
o
OUTPUT
OUTPUT
L,
R h
t
PHONE JACK
1
0k Q
SW101,
102
l±
"N"
to
1
-
2
(1)
80KHz
—
6dB/0CT
(2)
/
'{
12.7KHZ
—
6dB/OCT
7
'{
—
to
(3)
>h°-r>xli 600Q
1UT60I. to
(4)
IMQ a±c0Zt.
2
—
1
#
INPUTiST-j:
9
-
1
6.0dBm/1 kHz
M
OUTPUT
L
Rl/ R
^
^-6.0
±
1
.OdBm t
to
2-2
INPUTJST-il
-30dBm
WAfj'ft^^fPin
L/iB#.
L,
R co^
OUTPUT
1±. 1
kHz
«
*lpt
LTTaX)|EHl^<7)b
to
20Hz~1
1kHz
0±2 dB
12kHz
0±|dB
2-3
m.
$
2
-
2
0.08
%arcozto
2
—
4
INPUT
1
kHz
L,
R
OUTPUT
6.
OdBm
%aTTW'^ti^ Z
to
20Hz~1
1kHz
0±^ dB
12kHz 0 +
3
dB