NAD 7155 User manual

SERVICE
MANUAL
AM/FM
STEREO
RECEIVER

NAD
7155
SERVICE
MANUAL
NOTE:
This
manual
covers
all
versions.
A:
U.S.A.
Al:
Canada
B:
U.K,
B1:
Australia
C:
EUROPE
and
others
C1:
W-Germany
TABLE
OF
CONTENTS
LOCATION
MAP
SPECIFICATION
INTERNAL
VIEW
SUGGESTED
INSTRUMENTATION
HOOKUP
FM
ALIGNMENTS
AM
ALIGNMENTS
AMPLIFIER
ALIGNMENTS
AMPLIFIER
P.C.B.
LAYOUT
DIAGRAM
SCHEMATIC
DIAGRAM
(AMPLIFIER
SECTION)
TUNER
P.C.B.
LAYOUT
DIAGRAM
SCHEMATIC
DIAGRAM
(TUNER
SECTION)
WIRING
DIAGRAM
EXPLODED
VIEW
PARTS
LIST
EXPLODED
VIEW
ELECTRICAL
PARTS
LIST
PAGE

REAR
PANEL
1.
AC
Line
Cord.
9.
Phono
Input.
|
2.
AC
Convenience
Outlets
10.
Phono
Capacitance.
(Not
in
European
models)
11.
CD/Aux
Input.
3.
Speakers
A.
12,
Tape
1
Rec/Play.
4.
Speakers
B.
13,
Tape
2
Rec/Play.
5.
Antenna
Terminals.
14,
Preamp
Out,
Main
In
6.
AM
Rod
Antenna.
15.
Soft
Clipping.
7.
Phono
Ground.
16.
Speaker
Impedance.
8.
MM/MC.
17.
Bridging.
6 7 5
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INC.
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FRONT
PANEL
1,
Power.
Phones.
Speaker
Selector.
Bass.
Treble.
Bass
EQ.
Infrasonic
Filter
Defeat.
.
Mono.
.
Dyn
Sep
Defeat.
10.
Recording
Input
Selector.
11.
Listen
Input
Selector.
‘Service
PERSONNEL
12,
Low
Level.
43.
Loudness
Compensation.
14.
Volume/Balance.
15.
Tuning
Display.
16.
Status
Indicators.
17.
Pre-sets.
18.
Enter.
19.
AM/FM
20.
Up/Down
Tuning.
21.
Search.
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12
13

SPECIFICATIONS
NOTE:
Measurements
referenced
to
8
ohms
are
taken
with
the
Speaker
Impedance
Selector
set
to
“8
ohm
(High).
Measurements
for
4
and
2
ohms
are
taken
with
the
impedance
selector
at
‘4
ohm
(Normal)’’.
Specifications
are
measured
in
accordance
with
EIA
Standard
RS-490
(IHF
A-202)
for
amplifiers
and
ANSI-IEEE
Standard
185
(1975)
(IHF
T-200)
for
tuners,
Tuner
sensitivity
is
measured
via
75
ohm
coaxial
input
and
converted
to
equivalent
300
ohm
values.
Power
Amplifier
Section,
Stereo
Mode
CONTINUOUS
AVERAGE
POWER
OUTPUT
INTO
8
OHMS
(min.
RMS
power
per
channel
into
8
ohms,
20
Hz
-
20
kHz,
both
channels
driven,
with
no
more
than
the
rated
distortion).
Rated
distortion
(THD),
20
Hz
-
20
kHz.
Clipping
power
(max.
continuous
power
per
channel).
8
ohms:
4
ohms:
IHF
dynamic
headroom
at
8
ohms.
IHF
dynamic
power
(max.
short-term
power
per
channel).
8
ohms:
4
ohm:
2
ohms:
Slew
factor.
Slew
rate.
Damping
factor
(ref.
8
ohms,
at
50
Hz).
Input
impedance.
Input
sensitivity
for
1
W/55
W
out.
Power
amp.
gain.
THD
(Total
Harmonic
Distortion,
20
Hz
-
20
kHz,
from
250
mW
to
rated
output).
SMPTE
I.M.
(Intermodulation
Distortion
60
Hz
:
7
kHz,
4:1,
from
250
mW
to
rated
output).
IHF
I.M.
(CCIR
IM
Distortion,
19
to
20
kHz
at
rated
output).
Bridged
(Monophonic)
Mode
CONTINUOUS
AVERAGE
POWER
OUTPUT
INTO
8
OHMS
(min.
RMS
power
into
8
ohms,
20 Hz
-
20
kHz,
with
no
more
than
the
rated
distortion).
IHF
Dynamic
Headroom
at
8
ohms.
Dynamic
power
(max.
short-term
output,
8
ohms).
All
versions
except
USA.
55
W
(17.4
dBW)
0.03
%
65W
75
W
+2.6dB
100
W
100
W
130
W
>
50
20
V/usec.
>
50
22
k
ohms.
0.13
V/0.95
V
26.8
dB.
<
0.03
%
<
0.03
%
<0.03
%
125
W
(21
dBW)
+2.5dB
250
W
USA
version
only.
55
W
(17.4
dBW)
0.03
%
75W
90W
+3dB
110
W
130
W
150
W
150
W
(22
dBW)

Preamplifier
Section
Phono
Input
Input
impedance,
Input
sensitivity
(1
kHz),
Input
overload
at
20
Hz/1
kHz/20
kHz.
THD
(20
Hz
-
20
kHz)
and
IM
Dist.
at
+30
dB
level.
RIAA
response
accuracy.
S/N
ratio,
IHF
A-weighted,
with
cartridge
connected.
Line
Level
Inputs (Aux.,
Tape)
Input
Impedance.
Input
sensitivity.
Maximum
input
signal.
Signal
to
noise
ratio,
A-weighted.
Frequency
response,
20
Hz
-
20
kHz.
Outputs
Preamp
output
impedance.
Maximum
output
level.
Tape
output
impedance.
Tape
output
infrasonic
filter.
Controls
Treble.
Bass,
Speaker
equalization.
Infrasonic
filter.
Audio
muting
(low
level).
MM:
Mc:
MM:
MC:
MM:
Mc:
MM:
MC:
R
47k
ohms
C
100/200/320
pF
R
100
ohms
C
1000
pF
0.33
mV
for
1
W
out.
2.5
mV
for
55
W
out.
0.02
mV
for
1
W
out.
0.15
mV
for
55
W
out.
27
mV/230
mV/2
V.
1.2
mV/12 mV/88
mV.
<0.04
%
+0.5
dB.
80
dB
re
5
mV.
80
dB
re
0.5
mV.
R
10kohms;C
220
pF.
20
mV
for
1
W
out.
150
mV
for
55
W
out.
>10V
88
dB
re
1
W.
103
dB
re
55 W.
+0.5
dB.
800
ohms.
10
Vv.
1000
ohms
(buffered).
—3dB
at
15
Hz,
12
dB/octave.
+7
dB
at
10
kHz.
+7
dB
at
100
Hz.
+3
dB
at
70
Hz.
+6
dB
at
32
Hz.
—
3B
at
15
Hz,
12
dB/octave.
—
20
4B.
EM
Tuner
Section
Input
sensitivity
Mono,
—30
dB
THD
+N:
Capture
ratio
at
25,
45
&
65
dBf.
AM
rejection.
Selectivity,
Image
rejection.
R.
F.
intermodulation.
|.
F,
rejection.
SCA
rejection.
Subcarrier
suppression
(19
+
38
kHz).
THD
at
100
%
modulation,
Signal
to
noise
ratio,
A-weighted,
65
dBf.
Frequency
response,
30
-
15
kHz.
Stereo
separation
(Dyn
Sep
off),
AM
Tuner
Section
Usable
sensitivity.
Selectivity.
Image
rejection.
|,
F,
rejection.
Physical
Specifications
Dimensions
(width
x
height
x
depth).
Net
weight.
Shipping
weight.
Power
consumption.
Mono,
50
dB
S/N:
Stereo,
50
dB
S/N:
Stereo,
60
dB
S/N:
Alternate
channel:
Adjacent
channel:
Mono:
Stereo:
Mono:
Stereo:
1
kHz:
30
Hz
-
10
kHz:
50
usec.
deemphasis
75
psec.
10.3
dBf.
9.8
dBf.
(1.8
#V/300
ohms)
(1.7
#V/300
ohms)
15.8
dBf.
13.2
dBf.
(3.2
nV)
(2.5
uv)
33.2
dB.
32
dBf.
(25
nV)
(22
uv)
43.1
dBf.
42
dBf.
(78
nV)
(70
pv)
<1,.5
dB.
>
65
dB.
70
GB.
8
dB.
85
dB.
70
dB.
90
GB.
70
dB.
60
dB.
1
kHz
100
Hz
-
6
kHz
0,09
%
0.2%
0,09
%
0.3%
82
dB.
75
dB.
(typ.
80 dB
at
75
dBf)
+0.5
dB.
50
dB.
40
dB.
300
uV/meter.
35
dB.
50
dB.
50
dB.
42
x
10.8
x
38
cm.
16.5
x
4.25
x
15
in.
9.18
Kg./20
Ib,
4
oz.
10.6
Kg./23
Ib.
6
oz.
50/60
Hz
at
110,
120,
220
or
240
VAC.
340
W.

INTERNAL
VIEW
SUGGESTED
INSTRUMENTATION
HOOKUP
fi
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2
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OSCILLOSCOPE
FM
GENERATOR
AUDIO
OSC
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1
IN
(0)
|
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H
vINeUT—XINPUT
EXT.
MOD.
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1 1
t
USE
ONLY
IF
FM
GENERATOR
WITH
BUILT-IN
SWEEP
UNAVAILABLE
:
OSCILLOSCOPE
FM
GENERATOR
WITH
BUILT-IN
SWEEP
Rd
IE:
ST
10008
SWEEP
Y
INPUT
X
INPUT
[OUTPUT
RF
OUT.
VERT.
HORIZ,
$
¢
°
DETECTOR
PROBE
BALUN
AC.
VTVM
esa
fas
ee
cere
he
PIN1
IC
102
3000
UNIT
UNDER
TEST
AC
VTVM
INPUT
FROM
TUNER
IC:
TO
PIN1
Ic
102
TO
TUNER
GND.
AT
FRONTEND
out
TO
SCOPE
DISTORTION
METER
DISTORTION
PUT
Out
ry
PUT
Diodes
should
be
point-contact
germanium;
Some
commonly
available
types
are:
PICTORIAL
DIAGRAM
OF
DETECTOR
PROBE
RY
c2
CENTER
LEAD
TO
SCOPE
\
SHIELD
Keep
leads
as
shortas
minimize
stray
signal
0a80
OA81
AAIIS
1N60
1N34
1N22
possible,
to
pickup.

FM
ALIGNMENTS
NECESSARY
INSTRUMENTATION
FM
GENERATOR
(less
than
0.05%
THD)
STEREO
GENERATOR
(less
than
0.05%
THD,
more
than
50
dB
sep.)
AUDIO
GENERATOR
(not
necessary
if
FM
generator
has
built
in
sweep;
ie,
SOUND
TECHNOLOGY
ST
1000A
and
ST
1020A)
AC
VTVM's
(or
one
with
a
left/right
switch)-
THD
ANALYZER
(resolution
less
than
0.1%)
OSCILLOSCOPE
(5mV
or
better
sensitivity,
X
input
capability)
FREQUENCY
COUNTER
VOM
or
DMM
(high
impedance,
must
read
in
mV)
DETECTOR
PROBE
IMPORTANT
FRONTEND
oa
While
all
FM
generator
output
levels
hereafter
are
referred
to
the
300
ohm
input,
75
ohm
input
can
be
used,
but
be
aware
of
possible
equipment
groundloops
and
divide
the
RF
output
levels
by
2.
Before
alignments
commence
set
input
selector
and
record
selector
to
tuner
and
release
mono
dyn
sep
defeat
switches
(out).
Alignment
of
frontend
should
only
be
necessary
after
repair
to
frontend
or
crystal
oscillator
circuits
(pin
2
and
3
on
IC
110).
TUNING
VOLTAGE
(OSCILLATOR)
It
is
essential
to
check
tuning
voltage
before
aligning
the
rest
of
the
frontend.
Connect
DMM
between
ground
and
TP
102.
Tune
to
108
MHz
and
adjust
C
20
if
voltage
is
incorrect.
SPECIFICATION
24.7V
+
0.5V
Tune
to
88
MHz
and
read
voltage.
Adjust
L
6
if
voltage
is
incorrect.
SPECIFICATION
3.6V
+
0.5V>
Repeat
step
2
and
3
until
readings
are
within
tolerances.
RF
ADJUSTMENT
(TRACKING)
Connect
RF
generator
to
300
ohm
antenna
input
and
detectorprobe
to
pin
1
IC
102
with
ground
to
tunershield.
Adjust
sensitivity
of
oscilloscope
to
maximum
(SmV
or
better)
and
modulate
FM
generator
sweep
*
300
kHz
or
more.
Set
tuner
to
105
MHz,
enter
into
preset
5,
and
tune
generator
so
that
curve
appears
on
oscilloscope.
Turn
down
RF
input
level
so
that
curve
covers
approximately
1/2
of
oscilloscope
display.
Adjust
C
3,C
9,
C
11
and
C
15
to
maximum
curve
height
while
reducing
RF
input
to
keep
entire
curve
on
display.
Set
tuner
to
90
MHz,
enter
into
preset
1,
and
tune
generator
so
that
curve
appears
on
oscilloscope
display.
Adjust
L
1,
L
2,
L3
and
L
4
to
maximum
curve
height.
Repeat
steps
2,
3,
4
and
5
(use
preset
1
and
5)
until
both
frequencies
are
at
maximum
curve
height.
NOTE:
105
MHz
curveheight
is
typically
slightly
stronger
than
90
MHz.
IF
ADJUSTMENT
Set
tuner
to
approximately
98
MHz
(the
tuner
must
be
tuned
to
an
unoccupied
frequency)
enter
into
Preset
3,
and
tune
FM
generator
to
display
a
curve
on
oscilloscope.
Adjust
L
5
and
L
101
to
maximum
and
symmetrical
curve
on
the
display,
using
as
little
input
as
Possible.
NOTE:
Maximum
input
500
yV,
typical
curveheight
4
mV
at
150
uV
and
15
mV
at
300
nV.
|
i

DETECTOR
COARSE
ADJUSTMENT
(OPTIONAL,
NEEDED
ONLY
IF
DETECTOR
WAS
REPAIRED)
Reduce
sweep
modulation
level
to
+
75
kHz
and
set
input
level
to
300
uV.
Adjust
FM
generator
frequency
so
that
both
legs
of
the
inverted
U-shaped
curve
are
equally
high
on
the
display.
The
curve
should
be
almost
perfectly
symmetrical.
Disconnect
detectorprobe
from
tuner
and
oscilloscope.
Connect
either
of
the
tape
1
rec.
outputs
to
the
oscilloscope.
The
oscilloscope
should
now
display
a
diagonal
line.
Adjust
L
102
primary
(closest
to
IC
102)
to
maxi-
mum
curveheight
and
L
102
secondary
to
minimum
curve
height
and
straightest
possible
line.
Go
back
and
forth
between
primary
and
secondary
till
both
are
peaked.
NOTE:
Both
the
cores
should
be
within
1.5mm
from
the
top
of
the
form.
DETECTOR
ALIGNMENT
(FINAL)
Disconnect
detectorprobe
and
connect
tape
1
rec.
output
to
VTVM’s,
oscilloscope
and
distortion
analyzer.
Switch
stereo
generator
to
1
kHz
100%
(+
75
kHz)
mono
modulation
and
oscilloscope
to
normal
internal
sweep
0.2
mS
and
0.5
V/cm
sensitivity.
Detector
reference
frequency.
Reduce
FM
generator
output
level
while
monitoring
THD
from
left
channel.
When
THD
increases
to
3%,
fine
tune
the
FM
generator
frequency
to
minimum
THD.
Reduce
FM
generator
output
level
and
fine
tune
till
no
reduction
in
the
3%
THD
can
be
achieved
by
fine
tuning.
Use
this
frequency
for
all
the
follow-
ing
detector,
MPX
and
DYN
SEP
adjustments.
NOTE:
The
typical
input
level
for
this
3%
THD
should
be
1.6
pV
to
2.3
KV.
This
is
done
only
to
“line
up”
the
frequency
from
the
generator
to
the
tuner’s
frequency.
lf
IHF
usable
sensitivity
(-30
dB
THD
+
N
=
3.16%)
is
to
be
verified,
a
proper
IHF
bandpass-
filter
must
be
used.
Connect
DMM
across
TP
104
(negative)
and
TP
105
(positive).
Set
FM
generator
output
to
1000
uV
Adjust
L
102
primary
(closest
to
IC
102)
for
0
V
on
DMM.
TOLERANCE
+50
mv
Adjust
L
102
secondary
for
lowest
THD.
SPECIFICATION
less
than
0.1%
Repeat
steps
3,
5
and
6
till
no
further
improvements.
Record
the
DMM's
final
reading
for
use
later
in
the
adjustments.
(1
—
3)
AUTOSEARCH
LEVEL
Connect
DMM
between
ground
and
TP
107,
Increase
FM
generator
level
upwards
from
0
and
adjust
R
107
“MUTE”
so
that
DMM
reading
goes
from
0
V
to
approximately
4.8
V
at
10
uV
input.
TOLERANCE
£2uv
STEREO
DECODER,
MPX
FILTERS.
vco.
Connect
a
frequency
counter
and
a
200
k
ohm
resistor
in
parallel
between
ground
and
TP
108.
Set
FM
generator
to
1000
uV
output
and
no
modulation.
Adjust
R
164
“MPX
VCO”
for
a
19000
Hz
reading
on
the
counter.
TOLERANCE
+100
Hz
Disconnect
frequency
counter
and
resistor
and
depress
DYN
SEP
defeat
switch
(in).
Stereo switch
threshold.
Modulate
FM
generator
1
kHz
100%
left
only
plus
19
kHz
pilot
8
-
10%.

6
14
Increase
FM
generator
level
upwards
from
0
and
adjust
R
167
“ST
SW”
so
that
stereo
light
turns
on
and
audio
outputs,
as
watched
on
VTVM’s
and
oscilloscope,
switches
to
one
channel
only
at
10
uV
input
level.
TOLERANCE
+5
uv
NOTE:
When
turning
input
level
down
the
unit
will
switch
into
mono
at
a
lower
level,
typically
7
uV.
Stereo
separation.
Set
FM
generator
output
to
1000
uV,
modulate
left
channel
only.
Adjust
R
158
for
minimum
on
right
channel
VTVM.
Modulate
FM
generator
right
channel
only
and
adjust
R
158
for
minimum
on
left
channel
VTVM.
If
the
minimum
in
step
8
and
9
are
different,
adjust
R
158
so
that
the
readings
are
the
same
in
both
channels.
SPECIFICATION
better
than
50
dB
separation
MPX
filter
Turn
off
audiomodulation,
leaving
pilot
tone
only.
Disable
IHF
filter,
or
external
19
kHz
filter.
Check
19/38
kHz
suppression.
SPECIFICATION
more
than
60
dB
If
unit
does
not
meet
specification
adjust
FL
102
“MPX
FILTER”
on
left
channel
and
FL
103
“MPX
FILTER”
on
right
channel
to
minimum
output.
NOTE:
DO
NOT
ADJUST
THE
MPX
FILTERS
UNLESS
NECESSARY,
the
cores
are
brittle
and
break
easily.
Release
the
DYN
SEP
DEFEAT
switch
(out).
DYN
SEP
ADJUSTMENTS.
Turn
R
256
“DYN
SEP
OFF”,
R
249
and
250
“DYN
SEP”
fully
clockwise.
DYN
SEP
separation
effect.
Observe
output
from
left
channel
with
FM
generator
output
level
1000
nV
and
modulated
1
kHz
left
channel
only.
Reduce
audiomodulation
only
from
stereo
generator
so
that
left
channel
output
is
reduced
by
6
dB
(50%
stereo
modulation).
The
19
kHz
pilot
signal
MUST
REMAIN
modulated
8
-
10%.
Set
FM
generator
output
to
50
nV
and
adjust
R
249
“DYN
SEP”
for
—30
dB
separation
left
to
right
channel.
TOLERANCE
+2dB
Switch
modulation
to
right
channel
only
while
maintaining
the
same
modulation
levels:
Adjust
R
250
“DYN
SEP”
for
—30
dB
separation
right
to
left
channel.
TOLERANCE
+2dB
DYN
SEP
auto
defeat
level.
Set
generator
output
to
200
uV
and
adjust
R
256
“DYN
SEP
OFF”
so
that
separation
starts
increasing
when
watching
left
channel
VTVM.
Adjust
FM
generator
output
up
and
down
around
200
uV
and
make
sure
switching
occurs
around
200
HV.
TOLERANCE
+100
nV
—
30
nV
SYNTHESIZER
FREQUENCY
Tune
to
a
known
accurate
frequency
source,
i.e.,
broadcasting
station
or
synthesized/digital
display
FM
generator
preferably
in
the
midband
95
-
100
MHz.
Connect
DMM
across
TP
104
(negative)
and
TP
105
(positive).
Adjust
C
209
“FQ”
so
that
DMM
reads
the
same
as
recorded
in
E
—
7.
TOLERANCE
+10mV
R167
TP108

AM
ALIGNMENTS
A
wn
aR
won
OSCILLATOR.
Connect
DMM
to
TP
101
and
gnd.
Tune
to
1710
kHz,
Enter
into
preset
1.
Adjust
C
148
for
reading
of
31
+
0.5VDC,
Tune
to
520
kHz.
Enter
into
preset
2.
Adjust
L
103
for
reading
of
1.8
+
0.1
VDC.
Repeat
steps
2
and
3
until
within
tolerances.
ANTENNA,
IF
Swing
antenna
away
from
chassis
and
peel
back
label
(if
present)
to
expose
adjustment
tab.
Connect
DC
voltmeter
to
centertap,
R
208
and
gnd.
Tune
to
station
of
moderate
strength,
near
600
kHz.
Enter
into
preset
3.
Adjust
L
951
(move
tab
under
label
on
antenna)
for
maximum
reading
on
meter.
(Use
non-ineractive
tool,
such
as
plastic
or
wooden
stick.)
Adjust
L
104 and
L
106
for
maximum
reading
on
meter.
Tune
station
of
moderate
strength
near
1400
kHz.
Enter
into
preset
4.
Adjust
C
147
for
maximum
reading
on
meter.
Repeat
steps
3
and
5
until
no
further
improvement
is
seen.
9
kHz,
10
kHz
WHISTLE
FILTERS
Tune
to
quiet
spot
on
the
dial
(a
clear
frequency)
Connect
audio
osc.
to
base,
Q
117
(isolate
with
0.1
-
1.0
uF
capa.)
Connect
AC
VTVM
(or
scope)
to
TP
103.
Set
audio
osc.
to
10
kHz
(+
50
Hz)
1
V.
Adjust
FL
104
for
minimum
meter
reading.
Set
audio
osc.
to
9
kHz
(+
50
Hz)
1
V.
Adjust
FL
105
for
minimum
meter
reading.
SIGNAL
METER,
AUTO
STOP
R
208
controls
signal
strength
indication
and
auto
stop
level,
adjust
only
if
necessary,
to
correct
for
scan
stopping
on
excessively
weak
signals,
or
failure
to
stop
on
moderately
strong
ones.
NOTE:
When
finished,
lock
antenna
bar
adjustment
with
laquer
(nail
polish),
re-install
label.
12
TP101

AMPLIFIER
ALIGNMENTS
1
2.
IDLE
(QUIESCENT)
CURRENT
Connect
mV
meter
(DVM)
from
TP
701
to
TP
702,
left
chan.
(from
TP
751
to
TP
752,
right
chan.)
Adjust
R
721,
left
chan.
(R
771,
right
chan.)
so
that
meter
reading
is
20
-
25
mVDC.
NOTE:
Reading
may
take
a
few
minutes
to
stabilize;
re-check
after
offset
adjustment
(next
step.)
OFFSET
(CENTERING)
VOLTAGE:
Adjust
R
708.
left
(R
758,
right)
so
that
voltage
at
spkr.
terminals
is
0
+
50
mVDC.
NOTE:
Perform
these
adjustments
with
no
load,
volume
minimum.
14
MEMO

AMPLIFIER
P.C.B.
LAYOUT
DIAGRAM
SPEAKER
TERMINAL
PCB
LED
DISPLAY
PCB
Ee
lo.
ED)
SPEAKER
SWITCH
PCB
POWER
SWITCH
PCB
INPUT/OUTPUT
PCB
8
MAIN/CONTROL
AMP.
&
POWER
SUPPLY
PCB
3
E
Qercen
sao
72
-2149-0-2
ll
UD

(aowctes
ne
bait
LS
inte
who
NAD
7155
AMPLIFIER
SECTION
SCHEMATIC
DIAGRAM
Fao
ae
Mei
(230)
19
18

TUNER
P.C.B.
LAYOUT
DIAGRAM
DISPLAY
&
PRESET
SELECTOR
PCB
ANTENNA
TERMINAL
PCB
)
|
oonz-ze
TUNER
PCB
FRONTEND
PCB
UP/DOWN
PCB
20
21

SCHEMATIC
DIAGRAM
NAD
7155
TUNER
SECTION
Jase
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ns
vst
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23
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498%
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(038)
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WIRING
DIAGRAM
ANTENNA
TERMINAL
P.CB
(zo02a)
7500
INPUT
SPEAKER
TERMINAL
P.CB
(Z001A,B)
ilies
hea
alll
|
Fees
eee
Bw
(u958)
AC
OUTLET
L>
Way
POWER
TRANSFORMER
TUNER
PCB
(10238)
RED
LK
wat
wi]
ee
POWER
SWITCH
P.C.B
(SO79B)
Buk
Ac
INPUT
INPUT/OUTPUT
P.C.B.
(J013A)
Vico
BGG
ie
Va
C6
Siesnd?
ES.
ANS
MAIN/CONTROL
AMP.
&
POWER
SUPPLY
P.C.B.
(J0118)
ew
stereo]
RN
Sig
i
‘
es
a
SOFT
CLIPPING
LED
DISPLAY
P.C.B
(M106B)
UP/DOWN
P.C.B.
(S0B1A)
25
war
wat
SPEAKER
SWITCH
P.C.B
(S078A)

EXPLODED
VIEW
PARTS
LIST
Ref.
No.
Parts
No.
Descriptions
63-6272-0-0
FRONT
PANEL
1
2
62-1105-0-0
PUSH
BUTTON
-
SELECTORS
|
3
62-1105-1-0
PUSH
BUTTON
-
ON/OFF
|
4
62-3465-0-0
PUSH
BUTTON
FRAME
-
SINGLE
HOLE
5
62-3466-0-0
PUSH
BUTTON
FRAME
-
TWO
HOLES
i
6
62-3468-0-0
PUSH
BUTTON
FRAME
-
FOUR
HOLES
7
62-2317-0-0
ROTARY
KNOB
-
TONE
CONTROL/SELECTORS
8
62-2318-0-0
ROTARY
KNOB
-
BALANCE
9
62-2319-0-0
ROTARY
KNOB
-
VOLUME
10
62-3469-0-0
DISPLAY
PANEL
W
62-1106-0-0
PUSH
BUTTON
-
BLACK
12
62-1106-1-0
PUSH
BUTTON
-
LIGHT
BROWN
1
13
62-3471-0-0
PUSH
BUTTON
PLUNGER
|
14
62-1107-0-0
ROCKER
BUTTON
-
UP/DOWN
SEARCH
|
15
62-1108-0-0
PUSH
BUTTON
-
AUTO
SEARCH
16
88-
170-0-0
SPRING
-
PUSH
BUTTON
RETURN
7
63-5169-0-0
DISPLAY
WINDOW
18
92-2102-0-0
FOOT
-
SNAP
ON
TYPE
92-2103-0-0
FOOT
-
PLASTIC
RIVET
TYPE
|
19
63-1844-0-0
LABEL
:
THIS
IS
NOT
A
HANDLE.
|
|
20
63-1845-0-0
PLATE
(POLYESTER)
26
71-2584-0-0
FRONT
SUBCHASSIS
27
92-1175-0-0
INSULATOR
(PVC)
(B
B1C
C1)
28
71-2586-0-0
SIDE
CHASSIS
(L)
29
71-2587-0-0
SIDE
CHASSIS
(R)
30
71-2588-0-0
SUBCHASSIS
(FRONT
TO
REAR
SUPPORT)
31
71-2589-0-0
SUBCHASSIS
(LEFT
TO
RIGHT
SUPPORT)
32
71-1891-0-0
THERMAL
SWITCH
CLAMP
33
92-1225-0-0
INSULATOR
(PVC)
(A
A1
AC
RECEPTACLE)
34
92-1223-0-1
LOCKING
PLATE
-
IMPEDANCE
SWITCH
35
92-1224-0-0
LOCKING
PLATE
-
BRIDGING
SWITCH
36
71-2596-0-0
REAR
PANEL
(A
A1)
71-2601-0-0
REAR
PANEL
(C
C1)
71-2601-1-0
REAR
PANEL
(B
B1)
|
37
71-3107-0-0
CABINET
38
71-3104-0-0
BOTTOM
COVER
44
23-1318-0-1
POWER
TRANSFORMER
(A)
23-1318-1-0
POWER
TRANSFORMER
(C
C1)
23-1318-2-0
POWER
TRANSFORMER
(B
B1)
23-1318-3-0
POWER
TRANSFORMER
(A1)
45
23-1320-0-0
TUNER
POWER
TRANSFORMER
(A)
23-1320-1-0
TUNER
POWER
TRANSFORMER
(C
C1)
23-1320-2-0
TUNER
POWER
TRANSFORMER
(B
B1)
23-1320-3-0
TUNER
POWER
TRANSFORMER
(A1)
46
85-
258-0-0
POWER
CORD
(A)
85-
235-0-0
POWER
CORD
(CC1)
85-
240-0-0
POWER
CORD
(B)
85-
259-0-0
POWER
CORD
(B1)
85-
260-0-0
POWER
CORD
(A1)
47
82-2161-0-0
RECEPTACLE
(A
A1)
26

Ref.
No.
Parts
No.
Descriptions
48
82-2162-0-0
F
TYPE
ANTENNA
CONNECTOR
(A
Al)
82-
293-0-0
DIN
TYPE
ANTENNA
CONNECTOR
(B
B1
CC1)
50
81-
450-0-0
SLIDE
SWITCH
-
IMPEDANCE
SELECTOR
(AB
B1C
C1)
81-
452-0-0
SLIDE
SWITCH
-
IMPEDANCE
SELECTOR
(A1)
51
74-3104-0-0
HEAT
SINK
52
82-
118-0-0
JUMPER
CONNECTOR
53
65-
128-0-0
SHAFT
-
SELECTOR
54
62-3472-0-0
BUSHING
FOR
SHAFT
SELECTOR
55
62-3474-0-0
JOINT
FOR
SHAFT
SELECTOR
57
87-3242-0-0
GROUND
TERMINAL
58
87-3243-0-0
STUD
BOTTOM
COVER
SUPPORT
59
11-5120-0-0
AM
BAR
ANTENNA
60
62-3332-0-0
BUSHING
-
AC
POWER
CORD
61
63-1843-0-0
LABEL
(CAUTION
FOR
FUSE)
(A
A1)
66
JO13A
INPUT/OUTPUT
PCB
66-
1
82-2130-0-0
RCA
CONNECTORS
-
SINGLE
66-
2
82-2157-0-0
RCA
CONNECTORS
-
DOUBLE
66-
3
82-2159-0-0
RCA
CONNECTORS
-
TRIPLE
66-
4
81-
447-0-0
SLIDE
SWITCH
-
SOFT
CLIPPING
&
BRIDGING
66-
5
81-
448-0-0
SLIDE
SWITCH
-
PHONO
CAPACITANCE
SELECTOR
66-
6
81-
449-0-0
SLIDE
SWITCH
-
PHONO
MM/MC
SELECTOR
66-
7
81-
184-0-0
ROTARY
SWITCH
-
LISTEN
SELECTOR
66-
8
81-
185-0-0
ROTARY
SWITCH
-
RECORD
SELECTOR
66-
9
84-3184-0-0
PCB
CONNECTORS
(MALE)
-
3
POSITIONS
66-10
84-3201-0-0
PCB
CONNECTORS
(MALE)
-
5
POSITIONS
67
JO11B
MAIN/CONTROL
AMP
&
POWER
SUPPLY
PCB
67-1
41-
686-0-0
ROTARY
POTENTIOMETER
-
VOLUME
67-
2
41-
685-0-0
ROTARY
POTENTIOMETER
-
BASS
&
TREBLE
67-
3
81-2321-0-0
FUNCTION
SWITCH
BANK
(4
SWITCHES)
67-
4
81-2323-0-0
FUNCTION
SWITCH
BANK
(2
SWITCHES)
68
S078A
SPEAKER
SWITCH
PCB
68-
1
82-2158-0-0
HEADPHONE
JACK
68-
2
81-
183-0-0
ROTARY
SWITCH
-
LOUDSPEAKER
SELECTOR
69
S079B
POWER
SWITCH
PCB
69-1
81-2227-0-0
POWER
SWITCH
(A
A1)
81-2245-0-0
POWER
SWITCH
(B
B1C
C1)
69-
2
71-1894-0-0
FUSE
HOLDER
(A
A1)
71-1246-0-0
FUSE
HOLDER
(B
B1C
C1)
69-
3
FUSE
(A)
-
MDX-4
OR
MSL-4
FUSE
(A1)
-
MDX-3+2/10
125V
FUSE
(B
B1C
C1)
-
T2.0A
250V
70
Z001A/Z001B
SPEAKER
TERMINAL
PCB
70-1
82-2164-0-0
BINDINGPOST
-
LOUDSPEAKERS
71
M106B
LED
DISPLAY
PCB
72
FO18A
FM
FRONT-END
PCB
.
73
1023B
TUNER
PCB
73-1
71-1889-0-0
PCB
SUPPORT
73-2
74-
388-0-0
HEAT
SINK
73-3
81-2325-0-0
FM/AM
SELECTOR
SWITCH/AUTO
SEARCH
SWITCH
74
DO012A
DISPLAY
&
PRESET
SELECTOR
PCB
|
27

Ref.
No.
Parts
No.
Descriptions
74-1
7AMB8AS
FLUORESCENT
INDICATOR
TUBE
74-2
81-2326-0-0
MOMENTARY
SWITCH
-
PRE-SET
&
UP/DOWN
75
S081A
UP/DOWN
PCB
76
Z002A
ANTENNA
TERMINAL
PCB
76-1
82-2163-0-0
CONNECTORS
-
ANTENNA
TERMINAL
77
E014A
PHONO
AMP
PCB
77-1
84-3202-0-0
CONNECTORS
(FEMALE)
-
3
POSITIONS
77-2
84-3203-0-0
CONNECTORS
(FEMALE)
-
5
POSITIONS
80
TAPPING
SCREW
(PHILLIP’S
HEAD
3x6
Cr)
81
TAPPING
SCREW
(PHILLIP’S
HEAD
3x8
Cr)
82
TAPPING
SCREW
(PHILLIP’S
HEAD
3x6
BLK)
83
TAPPING
SCREW
(PHILLIP’S
HEAD
3x8
BLK)
84
TAPPING
SCREW
(WASHER
HEAD
3x6
Cr)
85
MACHINE
SCREW
S
(WASHER
HEAD
3x6
Cr)
87
MACHINE
SCREW
S
(PHILLIP’S
HEAD
3x8
BLK)
88
MACHINE
SCREW
(PAN
3x6
Cr)
89
MACHINE
SCREW
(PHILLIP’S
HEAD
3x
8
BLK)
90
MACHINE
SCREW
S
(PHILLIP’S
HEAD
4x6
Cr)
91
RETAINING
RING
(E
TYPE
5mm)
92
WASHER
(PLAIN
4-10-0.8
Ni)
93
WASHER
(TOOTHED
LOCK
B
4
Ni)
94
WASHER
(TOOTHED
LOCK
B
3
Ni)
(AA1)
95
NUT
(HEXAGON
M4-7-3,2
Cr)
96
TERMINAL
LUG
(A
A1)
97
TAPPING
SCREW
(PAN
2.6
x6
Cr)
98
MACHINE
SCREW
(PHILLIP’S
HEAD
3x6
Cr)
99
CABINET
SCREW
WITH
WASHER
(4
x6
BLK)
100
HEAD
PHONE
JACK
NUT
(HEXAGON
12-14-2)
101
WASHER
(PLAIN
12-18-0.5)
102
SPEAKER
SWITCH
NUT
(HEXAGON
7-10-2)
103
WASHER
(PLAIN
7-12-0.5)
104
TONE
CONTROLS
NUT
(HEXAGON
7-11-2)
105
VOLUME
CONTROL
NUT
(HEXAGON
9-11-2)
106
WASHER
(PLAIN
9-14-0.5)
107
F-CONNECTOR
NUT
(HEXAGON
UNF
3/8-11-2)
108
TERMINAL
LUG
(MET
31-0107)
28
EXPLODED
VIEW
29

ELECTRICAL
PARTS
LIST
NOTE:
This
is
not
a
complete
electrical
parts
list.
FRONTEND
P.C.B.:
FO18A
(EXPLODED
VIEW
REF.
NO.
72)
SYMBOL
NO.
PARTS
NO.
DESCRIPTIONS
Q1,Q2
3SK45(B)
F.E.T.
Q3
2SC461(B)
TRANSISTOR
04,05
2SC535(B)
TRANSISTOR
D1-D5
1SV55
DIODE,
VARIABLE
CAPACITANCE
ui
11-431
FM
ANTENNA
COIL
L2
11-432
FM
RF
COIL
L3,L4
11-433
FM
RF
COIL
LS
13-533
|FT
COIL
L6é
12-565
Osc
COIL
7
10uH
CHOKE
COIL
Ls
0.56uH
CHOKE
COIL
C3,
C9,C11,
C15,
C20
36-134
TRIMMER
CAPACITOR,
3-
11pF
c21
50V,
30pF,
J,
RH
CERAMIC
CAPACITOR
C22
50V,
15pF,
J,
RH
o
C23
50V,
10pF
+0.5pF,
RH
a
C24
5OV,
1pF
+0.25pF,
CK
i
C25
5OV,
1.5pF
+0.25pF,
CK
me
C34
50V,
8pF
+0.5pF,
CH
x
TUNER
P.C.B.:
1023B
(EXPLODED
VIEW
REF.
NO.
73)
SYMBOL
NO.
PARTS
NO.
DESCRIPTIONS
1C101
LA1222
INTEGRATED
CIRCUIT
1€102
LA1235
%
1C103
LA3390
"
1C104
LB1450
1C105
LA1245
ig
1€106,
IC107,
1C,122
uPC4558
*
1c108
NJMO072D
we
1€110
TC9157P
“J
1¢111
TD6104P
a
10114
L78M12
=
1C115
BA656
”
Q101
2SK212(E)
F.E.T.
Q102
-
0104
2SC929(E)
TRANSISTOR
Q105,
0109,
0110
2S8C1815(Y,GR)
7
Q113
-
0118,
0124
re
2
Q130
i
Q106
-
0108,
0111
2SA1015(Y,
GR)
a
Q112,
0119,
0125
ie
%
Q129
, =
Q122,
0123
2SK30A(GR)
F.E.T.
D101
-
D104,
D119
18446
DIODE
D134,
D135
er
ss
D105
-D114,
D126
DS442BT
fe
D132,
D133,
D136
-
D139
bd
D141,
0142,
D148
-
D151
D159,
0177
o
30
SYMBOL
NO.
PARTS
NO.
D118
GZA6.8Y
D127
GZA3.9Y
D164
GZA13X
D168
GZA36X
D170
GZA5.6Y
D124,
D125
FC66M
D165
-
D167,
D169
SR-1K
D171
DBA10B
L101
13-538
L102
13-536
L103
12-564
L104
13-348
L105
15-167
L106
13-347
FL101
19-138
FL102,
FL103
19-151
FL104
19-152
FL105
19-153
CF101
-
CF103
19-154
CF104
19-136
CF105
19-140
C104
50V,
68pF,
J,
RH
C105
50V,
100pF,
J,
RH
C121
50V,
0.68uF
C124
SOV,
3.3uF
C125,
C160,
C214
50V,
2.2uF
C126,
C169,
C215
SOV,
1uF
C147,
C148,
C209
36-136
C163,
C204
SOV,
0.22uF
C201,
C243
SOV,
0.1uF
C202
50V,
0.33uF
C213
5.5V,
0.047uF
C245
50V,
68pF,
J,
eal
5O0V,
15pF,
J,
RH
R107,
R167
20KQ,
B
R158,
R208
50KQ,B
R164,
R249,
R250
10KQ,
B
R185
6.8KQ,
1/2W
R256
5KQ,B
R311
2402,
1W
R322
220KQ
x
5
XTAL201
19-205
$103,
$104
81-451
$105
i
FU201
MDL1/10
100mA
FU202
MDL3/8
315mA
31
DESCRIPTIONS
ZENER
DIODE
)
VARACTOR
DIODE
RECTIFIER
IFT
COIL
FM
DETECTOR
COIL
AM
OSCILLATOR
COIL
450KHz
MATCHING
COIL
CHOKE
COIL,
120uH
IFT
COIL
ANTIBIRDY
FILTER
)
LOW
PASS
FILTER
CERAMIC
FILTER
CERAMIC
CAPACITOR
ELECTROLYTIC
CAPACITOR,
LOW
LEAKAGE
TRIMMER
CAPACITOR,
5.2
-
30pF
ELECTROLYTIC
CAPACITOR,
LOW
LEAKAGE
MEMORY
BACKUP
CAPACITOR
CERAMIC
CAPACITOR
VARIABLE
RESISTOR
CARBON
RESISTOR
VARIABLE
RESISTOR
OXIDE
METAL
RESISTOR,
RSF1B
RESISTOR
ARRAY
CRYSTAL,
7.2MHz
DEEMPHASIS,
SLIDE
SWITCH
9/10KHz,
as
FUSE,
250V,
1/10A
(A
VERSION)
!
FUSE,
250V,
100mA
(B,
C
VERSION)
FUSE,
250V,
3/8A
(A
VERSION)
FUSE,
250V,
315mA
(B,
C
VERSION)
;
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