Akai AA-A35 User manual

VWSEV-VV
AKAI service manual
pocttg S.
= Ses
COMPUTER CONTROLLED STEREO RECEIVER
move.
AA-A35/L

ABBREVIATIONS FOR SERVICE MANUAL
MODEL AA-A35/L
ABBREVIATION EXPLANATION
AC Alternating Current
A/D Analog/Digital
AGC Auto Gain Control
ALC Auto Level Control
AM Ampritude Modulation
CK ClocK
D Data
DET DETector
FLD (FL DISPLAY)
“FM
FREQ
GND
IF
INV
Lw
MANU
MC
MM
MPX
MW
osc
PLL
RST
SENS
SM
ST
sw
FLuorescent Display
Frequency Modulation
FREQuency
GrouND
Intermediate Frequency
INVert
Long Wave
MANUal
Moving Coil
Moving Magnet
Multi PleX
Medium Wave
OSCillator
Phase Locked Loop
ReSeT
SENSitivity
Signal Meter
STrobe
SWitch

COMPUTER
CONTROLLED
STEREO
RECEIVER
MODEL AA-A35/L
SECTION 1 SERVICE MANUAL .................05: 3
SECTION 2 PARTS LIST .............-. 0.0. eee eee 23

SAFETY INSTRUCTIONS
SAFETY CHECK AFTER SERVICING
Confirm the specified insulation resistance between power cord plug prongs and externally exposed parts of the set is
greater than 10 Mohms, but for equipment with external antenna terminals (tuner, receiver, etc.) and is intended for
{C]
or
[A],
specified
insulation
resistance
should
be
more
than
2.2
Mohms
(ground
terminals,
microphone
jacks,
headphone jacks. line-in-out jacks etc.)
PRECAUTIONS DURING SERVICING
1. Parts identified by the A\ symbol parts are critical for safety.
Replace only with parts number specified.
2. In addition to safety, other parts and assemblies are specified for conformance with such regulations as those
applying to spurious radiation. These must also be replaced only with specified replacements.
Examples: RF converters, tuner units, antenna selector switches, RF cables, noise blocking capacitors, noise
blocking filters, etc.
3. Use specified internal wiring. Note especially:
1) Wires covered with PVC tubing
2) Double insulated wires
3) High voltage leads
4. Use specified insulating materials for hazardous live parts. Note especially:
1) Insulation Tape
2) PVC tubing
3) Spacers (Insulating Barriers)
4) Insulation sheets for transistors
5) Plastic screws for fixing microswitch (especially in turntable)
5. When replacing AC primary side components (transformers, power cords, noise blocking capacitors, etc.), wrap
ends of wires securely about the terminals before soldering.
o> cp
Observe that wires do not contact heat producing parts (heatsinks, oxide metal film resistors, fusible resistors, etc.).
Check that replaced wires do not contact sharp edged or pointed parts.
Also check areas surrounding repaired locations.
Use care that foreign objects (screws, solder droplets, etc.) do not remain inside the set.
$2.08, Sos
VOLTAGE CONVERSION
Models
for
Canada,
USA,
Europe,
UK
and
Australia
are
not
equipped
with
this
facility.
Each
machine
is
preset
at
the
factory
according
to
destination,
but
some
machines
can
be
set
to
110V, 120V,
220V
or
240V
as
required.
If
your
machine’s
voltage
can
be
converted:
Before
connecting
the
power
cord,
turn
the
VOLTAGE
SELECTOR
located
on
the
rear
panel
with
a
screwdriver
until
the
correct
voltage
is
indicated.

SECTION 1
SERVICE MANUAL
TABLE OF CONTENTS
I. SPECIFICATIONS 4
Hf. DISMANTLING OF UNIT .. 5
MW. CONTROLS .................. 6
Iv. PRINCIPAL PARTS LOCATION ... eh hindary sane acca Oo]:
V. DESCRIPTION OF THE CIRCUIT OPERATION .................. 8
5-1 AMPLIFIER PERFORMANCE . 8
5-2. TUNER PERFORMANCE... ........ 0... cee cee eee ot
VI. AMPLIFIER SECTION ADJUSTMENT .................00.0000. 14
6-1 THE INSTRUMENT CONNECTION ...........2.--5.00000. 14
6-2 MAIN AMP PC BOARD ADJUSTMENT POINTS.............. 14
6-3. POWER LEVEL METER ADJUSTMENT................-... 14
VII. TUNER ADJUSTMENT ......... 006 c cece cece cee ene 15
7-1 THE INSTRUMENT CONNECTIONS ...............-000005 15
7-2. TUNER, FRONT END, MPX PC BOARD ADJUSTMENT POINTS ... 16
7-3 HOW TO CALL THE PRESET FREQUENCY FOR
THE TUNER ADJUSTMENT 17
7-4 FM SECTION ADJUSTMENT..........-....-05 acted . 18
7-5. LW SECTION ADJUSTMENT...... ees . 19
74 AM (MW) SECTION ADJUSTMENT ie 219
Vil. PC BOARD TITLES AND IDENTIFICATION NUMBERS............ 20
For basic adjustments, measuring methods, and operating principles, refer to GENERAL TECHNICAL
MANUAL.
‘SERVICE MANUAL AA-A35/L

Il. SPECIFICATIONS
FM TUNER SECTION
TUNING FREQUENCY RANGE
87.5MHz to 108.0MHz
USABLE SENSITIVITY (IHF)
11.2dBf (300ohms)
QUIETING SENSITIVITY (IHF) (S/N = 50dB)
16.2dBf (Mono)/37.2dBf (Stereo)
CAPTURE RATIO 1,5dB
SELECTIVITY (HF) 60dB (400kHz)
IMAGE REJECTION 85dB
IF_REJECTION 90dB
SPURIOUS REJECTION 90dB
AM SUPPRESSION 60dB
S/N_(HF)
75dB (Mono)/654B (Stereo)
HARMONIC DISTORTION
0.1% (Mono)/0.3% (Stereo)
STEREO SEPARATION
45dB (1kHz)
LW TUNER SECTION (AA-A35L only)
TUNING FREQUENCY RANGE
146kHz to 353kHz
USABLE SENSITIVITY (IHF) 800uV/m
SELECTIVITY (IHF) 30dB
IMAGE REJECTION 45aB
IF_REJECTION SSdB
S/N 35dB
T.H.D 2.0%
ANTENNA Loop antenna
AM TUNER SECTION (MW for AA-A35L)
TUNING FREQUENCY RANGE
530kHz to 1,610kHz for USA and Canada
531kHz to 1,602kHz for other countries
USABLE SENSITIVITY (IHF) 300uV/m
SELECTIVITY (IHF) 25dB
IMAGE REJECTION 40dB
IF REJECTION 55dB
SiN 404B
T.H.D. 1.0%
ANTENNA Loop antenna
AMPLIFIER SECTION
RATED POWER OUTPUT
20Hz to 20kHz
8 ohms
ASW x 2/0.02%
1kHz 53W x 2/0.02%
MUSIC POWER 100W
POWER BANDWIDTH (IHF, —3dB, 8 ohms) SHz to 70kHz/0.1%
S/N PHONO 75dB
AUX 98dB
RESIDUAL NOISE (8 ohms) 0.5mV
CHANNEL SEPARATION (IHF) PHONO/AUX 65dB (1kHz)
DAMPING FACTOR (1kHz, 8 ohms) 50
OUTPUT SPEAKER A or B 4 to 16 ohms
A+B 8 to 16 ohms
INPUT SENSITIVITY/IMPEDANCE PHONO 2.5mV/100kohms
AUX/TAPE 150mV/47kohms
OUTPUT LEVEL/IMPEDANCE TAPE REC 150mV/3kohms
FREQUENCY RESPONSE PHONO (RIAA) +0.5dB (30Hz to 15kHz)
AUX/TAPE 5 Hz to 100kHz, ~3dB
TONE CONTROL BASS +8dB (100Hz)
TREBLE +8dB (10kHz)
FILTER SUBSONIC —3dB/18Hz
PHONO MAX. INPUT (MM) 150mV
POWER REQUIREMENTS
120V, 60Hz for USA & Canada
220V, 50Hz for Europe except UK
240V, 50Hz for UK & Australia
110V/120V/220V/240V, 50/60Hz switchable for other countries
DIMENSIONS
440(W) x 110(H) x 345(D) mm
WEIGHT
8.4kg
* For improvement purposes, specifications and design are subject to change without notice.
‘SERVICE MANUAL AA-A35/L:

il. DISMANTLING OF UNIT
In case of trouble, etc. necessitating dismantling, please
dismantle in the order shown in the photographs.
Reassemble in reverse order.
¥ SCREWS = 2
UPPER COVER
e SCREWS
BOTTOM COVER
F SCREWS
n= SERVICE MANUAL AA-A35/L-

Ill. CONTROLS
ihm
Fig. 3-1 Front View
ALCO.
ac
Sonzove
2or2aov.
Soroane
sow
set nas te we 4
am step Notes strc tenu ht asconne
SH) oxrieakie wisest scbrcsceuta Wo cC”
|
|
ru be ipa ® ®
Fig. 3-2 Rear View
1, POWER SWITCH 17. ACOUSTIC MEMORY BUTTON
2. TONE CONTROL (BASS, TREBLE) BUTTONS 18. SPEAKER SELECTORS (A and 8}
3. BALANCE BUTTON 19. PHONES JACK
4. STATION MEMORY (1 to 8 & 9 to 16) BUTTONS 20. PHONO JACKS
5. BAND SELECTOR (FM, AM(MW), LW) BUTTON 21. GROUND TERMINAL
6. TUNING CONTROL BUTTON 22. TAPE 1 (REC/PLAY) JACKS
7. FL DISPLAY 23. TAPE 2 (REC/PLAY) JACKS
8. PRESET STATION BUTTONS 24. VOLTAGE SELECTOR mode only)
9. INPUT SOURCE SELECTOR BUTTONS 25. SPEAKER TERMINALS (A and B)
(CD(AUX), PHONO, TAPE 1, TAPE 2) 26. AC POWER CORD
10. DIRECT ACCESS VOLUME CONTROL 27. AC OUTLETS
11, DEFEAT BUTTON 28. AM STEP/FM DE-EMPHASIS SELECTOR
12. ACOUSTIC MEMO Al and A2 BUTTONS ({U]| modei only)
13. SCAN AUTO/MANU SELECTOR BUTTON 29. RESET BUTTON
14, FM MODE AUTO/MONO BUTTON 30. ANTENNA TERMINALS
15. SUBSONIC FILTER SWITCH 31. CD(AUX) JACKS
16. SAFETY SET/CALL BUTTON
‘SERVICE MANUAL AA-A35/L

Iv. PRINCIPAL PARTS LOCATION
POWER SWITCH FLO PCB Aloosasoza
FLO INDI
SUBSONIC FILTER SW SW2
SPEAKER SW SWI
PHONE PCB Alo0sA504c
MEMBRAN VOLUME VR9OI
HEAD PHONE JACK Jt
Fig. 4-1 Front View
POWER TRANSFORMER:
Aa-A35T-30 [CA)
ao
TUNER
PCB
PIN
Jack
PCB
atoo7es0za
(WAGES)
AA-A35)
A1007A5038
a SPEAKERIECE. Al007B507A [B.E} 35L)
50 Aloogasoze FRONT END PCB
7o AIOO8A504F 4304045200
Lace |
su
POWER PCB VARTICAL PCB MPX PCB. CONTROL PCB
aloosasoio
[U)
aloosasois
(0)
al00785028
[U-A.CEVS}(AA-A38)
Algoeacoze
503E
Al008A5038
100785078
[B.E)(AA-A35L)
~
PRE
AMP
PCB
S04E
[EVES]
‘A100845048
‘IOOTA5OSA
MaIN AMP PCB
aloosasora ()
Fig. 4-2. Top View
SERVICE MANUAL AA-A35/L.

V.
DESCRIPTION
OF.
THE
CIRCUIT
OPERATION
eee
5-1.
AMPLIFIER
PERFORMANCE
5-1-1
General
Description
(1)
Functions
a)
Input
Selector
Control
This
microcomputers
is
capable
of
controlling
analog
switch
TC9164N
that
serves
as
the
input
selector.
Three
input
systems
that
include
PHONO,
CD,
and
TUNER,
and
two
monitoring
systems
that
include
TAPE
|
and
TAPE
2
may
be
controlled.
b)
Direct
Access
Volume
Control
Reads
voltages
detected
out
of
the
sound-volume
touch
control
through
an
A/D
converter,
and
sets
the
electronic
potentiometer
in
accordance
with
the
read
data.
In
this
process,
any
designated
setting
will
be
reached
from
the
earlier
potentio-
meter
position
by
fading
in
or
out.
c)
Balance
Control
By
setting
various
level
differences
between
Lch
and
Rch
on
the
main
control,
up
to
a
maximum
of
30dB
L-R
level
offsets
may
be
created.
d)
Tone
(BASS/TREBLE)
Control
Operates
the
tone
control
potentiometer
(TC9156P)
in
2dB
steps
up
to
a
maximum
of
+10dB,
and
thereby
performs
as
an
electronically
controlled
tone
circuit.
f)
Acoustic
Pattern
Storage
By
this
function,
stores
in
the
microcomputer
two
patterns
of
the
tone
control
circuit
settings,
and
enables
the
instant
loading
of
either
of
the
stored
patterns.
g)
Volume
Control
Safety
Function.
With
the
touch
contro!
operated
direct
access
sound
volume
system
that
enables
the
instant
setting
of
any
preferred
sound
volume
level,
the
danger
exists
that
the
inadvertent
touch
of
a
higher
position
of
the
control
will
cause
a
sudden
emission
of
unexpectedly
high
sounds
from
speak-
ers.
A
time
lag
measure
in
the
form
of
fade-in’s
has
been
provided
to
enable
coping
with
the
above
danger,
but
as
an
added
and
positive
precau-
tion,
this
safety
function
has
been
added
on
that
suppresses
all
sounds
louder
than
a
level
set
in
advance.
h)
TUNER
Direct
Function
This
function
will
set
the
input
selector
at
TUNER
upon
receiving
data
from
the
microcomputer
(A1007T)
for
the
tuner
that
is
output
as
soon
as
the
tuner
has
been
operated.
PIN NO
©® © © © ©
SINGLE PRESSING
CONTINUOUS
DEPRESSIONS
5-1-2
Key
Input
and
Dynamic
FL
Display
Strobes
Key
inputs
and
FL
displays
are
both
handled
dynam-
ically,
and
their
basic
clock
signals
generated
by
the
ITMR
interrupt
(1,024
Hz)
for
the
output
of
strobe
signals.
msec >|
oe Max re0nsee
R50
RSt
Fig. 5-1
5-1-3.
Acceptance
of
Key
Inputs
sl
zamsec
s0oms 150 150 10 150 150
Fig. 5-2
© Chatterings will be absorbed for 24 msec.
©
Continuous.
depressions
will
be
accepted
first
at
24
msec
after
the
depression
start,
second
at
500
msec
after
the
first,
and
then
at
every
150
msec
thereafter.
e
All
multiple
depressions:
shall
be
inhibited.
Once
a
multiple
depression
is
made,
no
key
inputs
will
be
accepted
until
after
all
of
the
depressed
keys
have
been
released.
5-1-4 Key Processings
(1). [PHONO], [CD]
Sets
the
input
selector
(TC9164N)
for
either
of
the
input
modes
keyed
in,
and
makes
due
indications
for
it.
Nothing,
however,
will
occur
when
the
depressed
key
mode
has
already
been
engaged.
When
either
TAPE
1
or
TAPE
2
has
been
keyed
on,
the
displays
for
a
tape
monitored
input
will
be
flashed
on
and
off
for
10
times
at
a
1/2
duty
and
once
every
second,
to
alert
the
operator
of
the
ongoing
tape
monitoring.
In
addition,
when
serial
data
is
being
transferred
to
the
analog
switch,
the
—_——
SERVICE
MANUAL
AA-A35/L
ON
Or
8

el
electronic potentiometer will be muted, to prevent
the leakage of switching noises to the output circuit.
(The AA-A35/L has no “TUNER” key, but the neces-
sary input selection will be made by command data
from the micro-computer (A1007T) incorporated in
the tuner.)
(2) {TAPE 1], [TAPE 2]
Each single pressing of either key will switch its
monitoring status between ON and OFF from one to
the other, and its indication also turn ON and OFF
accordingly. In addition, during the transfer of serial
data to the analog switch, the electronic potentio-
meter will be muted to prevent the leakage of
switching noises to the output.
This, however, does not apply to TAPE 1 key opera-
tions with TAPE 2 in an ON mode.
(3) [VOLUME]
When the sound volume display is being made, either
fades the sound volume display is being made, either
fades in or fades out to the touched position from an
immediately preceding level. The phasing speed will
be 2dB per 60 msec. However, when the touched
position is above the “Safety” engaged position, the
foregoing operation will be made only up to that
“Safety” position. As for the display, the touched
position (within the “Safety” range) will instantantly
be displayed upon touching.
When either the Balance or the Safety Level is being
displayed, the display will be switched to the
Volume. Operations thereafter will conform with the
above process.
(4) [BALANCE L], [BALANCE R]
When the Balance is being displayed, data will be
transferred to provide the designated level offsets
between Lch and Rch of the electronic potentio-
meter, and the display will also synchronize there-
with. When continuously depressed, however, the
potentiometer setting will start varying at 500 msec
after the depression start, and will thereafter vary at
2dB per 150 msec, but linger for 750 msec at the
center position when passing through it. (The display
will vary at 2 dB per step in the immediate vicinity of
the center position, but at 4 dB per step in all other
areas.)
When these keys are pushed while either the Volume
or the Safety Level is being displayed, the display will
be switched to the Balance.
(5) [SAFETY]
@ When either the Volume or Balance position is
being displayed:
A single press of the key will first have the Safety
Level position at the time displayed. This display
will revert to the Volume position display 5
seconds later, but if the Safety key is depressed
continuously for one second or longer, the display
will be switched to that of the Volume, and the
Safety indicator will flash on and off every second
at a 1/2 duty. This signifies a Safety changing
mode to have been engaged, where any Volume
level up to Max may be selected, and the mode
will be sustained for one ‘minute. In other words,
the one minute after the beginning of the Safety
flashing represents a Safety Level setting time
duration.
@ When the Safety indicator is flashing on and off:
The Volume position touched in this duration will
be set as the Safety Level that represents the
sound volume level not be exceeded by any sub-
sequent acoustic output. As long as the Safety
Level set is other than the maximum potentio-
meter position, the Safety indicator will be lit
steadily, but when it is at the maximum position,
the indicator will go off.
(6) [BASS+], [BASS—] , [TREBLE+] , [TREBLE-]
Each single pressing of one of these keys will either
raise or lower the electronic potentiometer for either
BASS or TREBLE. When it is depressed contin-
uously, the first potentiometer up/down shifting
operation will be performed when 500 msec have
elapsed since the depression start, and the subsequent
operation at the rate of 150 msec per step. When the
shifting passes through the center position, it will
linger there for 750 msec before moving further on.
The display will also vary conforming with individual
key operations.
(7) [DEFEAT]
Restores the BASS/TREBLE positions all at the
center, regardless of their earlier potentiometer posi-
tionings.
(8) [MEMO]
Engages an acoustic pattern storage standby mode.
At this time, the ACOUSTIC MEMO indicator will
turn on, and the Al and A2 indicators flash on and
off for 10 times at a 1/2 duty in l-second cycles
(at 1 Hz).
Even before 5 seconds are up, the standby mode may
be disengaged by pushing any other key than [Al]
and [A2].
(9) [At], [A2]
@ When at Standby for Acoustic Pattern Storage:
Stores the current BASS/TREBLE positions in
the memory, and will disengage the storage
standby mode.
@ When in any other mode than Acoustic Pattern
Storage Standby:
Loads the stored BASS/TREBLE positions, that is,
sets the potentiometers instantly at those positions
and their displays at the same time.
SERVICE MANUAL AA-A35/{L————————————
9

5-1-5 Input Selector Analog Switch (TC9164N)
Controls the electronic potentiometer (TC9176P) and
the tone potentiometer (TC9156P).
(1) Serial Data Structure
The serial data is composed of 3 parallel bits that
include DATA, CK, and ST, and the numbers of serial
bits of the individual potentiometers have been made
as follows:
TC9164N > 14 bits
TC9176P > 20 bits
TC91S6P > 18 bits
Control lines DATA and CK for the TC9176P and
TC9156P have been made common with control lines
ST-WR and CE for A/D converter LC7910, because
A/D conversion and data transfers to the potentio-
meters will never occur simultaneously, and no
changes in the status of potentiometers will take
DATA(R70,91)
[Data Timing Schematic Diagram]
Pin @\
Pin @,@)
CKIR7I,92)
Pin ©.
ST(R72,73)
14/20/18 BIT
;
(2) Data Buffers
Fig. 5-3
Data buffers for the TC9146N are formed in RAMs
MFSRDO through MFSRD3, and those for the
TC9176P and TC9156P in RAMs MVSRDO through
MVSRD4. Their allocation charts are shown in Tables
place as long as no ST are issued. 5-1 to 5-3.
a) Buffers for the Input Selector Switch (TC9164N)
MFSRD3 MFSRD2 MFSRD1 MFSRDO
~ oN wa
2255/2828 % ge th
Pm Oo ze A me 8 ial
0 o 1 1 £0 1 1 )0 1 0 O | —> Fixed Data
ON OFF Table 5-1
Bits 2 and 3 of MFSRD1 will not be transmitted.
b) Buffers for the Master Potentiometer (TC9176P)
MVSRD4 MVSRD3 MVSRD2 MVSRD1 MVSRDO
LR 0 | 2 4 6 8 | 0 10 20 30 | 40 50 60 70 | C, Cy C3 Cy
0 0 0 O 1 | —> Fixed Data
Table 5-2
c) Buffers for the Tone Potentiometer (TC9156P)
MVSRD4 MVSRD3 MVSRD2 MVSRD1 MVSRDO
+5 +4 43 42 | +1 0 te 29 3-4 “5 LI R CG CG C3
0 0 1 1 0 I O | —>+ For BASS
0 0 1 1 1 0 O | —~+ For TREBLE
Table 5-3
SERVICE MANUAL AA-A35/L
10

5-2. TUNER PERFORMANCE
5-2-1 General Description
(1) Functions
a) 20-Ch or 16-Ch Random Presetting of Stations
When initialized, discrimates between A45 and
A35/25, and against A45, enables 10 stations each
front (1 to 10) and back (11 to 20) or a total of
20 stations to be preset, while against A35/25,
enables 8 stations each front (1 to 8) and back
(9 to 16) or a total of 16 stations to be preset.
The presetting permits the random storage of
station data irrespective of band, and for FM
stations, the MONO/STEREO segregating data
will also be contained in the storage.
b) Two Tuning Styles: AUTO and MANUAL
The AUTO Scan Tuning that once the UP/DOWN
key is pushed, will continue scanning until a
station is captured, and once it is captured, will
stop scanning, and the MANUAL Tuning that will
scan only when the key is held down, and when it
is released, will stop scanning, are the two tuning
styles enabled.
(LW is shifted in 1K steps for MANUAL and 9K
steps for AUTO.)
c) Switching of MONO and STEREO Receiving
Modes
The MONO/STEREO mode switching function has
been incorporated for FM reception, and is also
included in the stored station presetting data.
5-2-2 Acceptance of Key Input
SINGLE PRESSING
i
2amsec
CONTINUOUS
DEPRESSIONS
ee!
Pele te te ate
Soom: 50 50 50 $0 50
Fig. 5-4
© Chatterings will be absorbed for 24 msec.
© Continuous depressions will be accepted first at 24
msec after the depression start, second at 500 msec
after the first, and then at every 50 msec thereafter.
@ All multiple depressions shall be inhibited. Once a
multiple depression is made, no key inputs will be
accepted until after all of the depressed keys have
been released.
5-2-3 Initial Setting (RST Mode)
a) FL Display:
INPUT SOURCE = pmEser ———>
TUT fo ewacre
TM
scan woos it
Fig. 5-5
b) The received frequency will be at the lowest in the
FM band for each destination:
c) The mode will be STEREO (FM AUTO).
d) The scan mode will be MANUAL.
e) All the preset channels will be at the lowest FM
frequency.
f) The last frequencies of individual bands of the
tuner will be the lowest frequencies.
5-2-4 Status in a Backup Mode
Basically, the status immediately before engaging the
backup will all be sustained, but slight deviations will
be involved, as listed below.
a) When a backup mode is engaged during AUTO
SCAN, the scanning will stop.
b) When a backup mode is engaged in a storage stand-
by mode, the standby will be disengaged.
c) The pre-backup status will be sustained for about
3 weeks.
5-2-5 Active and Non-Active Modes at Tuner
(1) Active Mode
This is a mode after the data has been transmitted to
the microcomputer (A1007A) of AMP to have the
input selector of AMP switched to TUNER, that is, a
mode where all the tuner performance has been
enabled. :
The data for the microcomputer of AMP will be
transmitted from port R4, (A1007T Pin @) when
the BAND, UP/DOWN, and Preset CH keys have
been pushed, and its timing will be as illustrated
below.
Pin @)
R4I (A007 T)
SERVICE MANUAL AA-A35/L:

a
Se
(2)
Non-Active
Mode
This
is
a
mode
where
the
tuner
performance
has
been
partially
constrained.
It
is
engaged
by
detecting
an
(H]
level
of
the
line
connected
to
R7,
(A1007T
Pin
15)
of
the
subject
microcomputer,
which
has
been
brought
about
by
the
microcomputer
of
AMP
in
switching
the
input
selector
of
AMP
to
other
than
TUNER,
either
PHONO
or
CD,
and
by
juding
the
tuner
thereby
not
to
be
listened
to.
Relative
to
the
display,
the
frequency
display
will
be
extinguished,
and
bars
displayed
instead,
to
signify
a
non-active
mode.
wor sounce — pmesey ——7
cry !
Lu I
scan MODE tear
Fig. 5-7
Relative
to
the
operating
performance,
will
accept
only
the
BAND,
UP/DOWN,
and
Preset
CH
keys,
and
reject
all
the
other
keys.
5-24
Auto-Tuning
MUTING OUTPUT (R71)
Pin (4 (aioo7T)
5-2-7
Tuner
Output
Muting
This
microcomputer
will
mute
the
tuner
signal
when
the
BAND
data
or
PLL
data
is
changed
by
the
[BAND],
[UP],
[DOWN],
[MODE],
or
Preset
CH
key,
or
when
the
receiving
mode
is
changed.
In
the
muting
process,
when
50
msec
have
elapsed
since
the
initial
muting
start,
data
transfer
and
other
processings
will
be
made,
and
then,
450
msec
after
these
processes
have
been
concluded,
the
muting
will
be
disengaged.
We
will
call
the
initial
part
“pre-muting”
and
the
latter
trailing
part
“after-
muting”.
The
diagram
below
illustrates
the
above
arrangement.
BAND ]
key
INPUT
PULL
DATA
CHANGE
OZ
il
et
somsec ‘asomsec
MUTE
ON
MUTE
OFF
Fig. 5-10
As
exceptional
cases,
when
an
earlier
muting
process
is
still
ongoing
upon
receipt
of
another
key
input,
the
Pin
50
msec
pre-muting
will
be
omitted.
AUTO STOP INPUT
R91 (AlOO7T)
RADIO
starion
Eres
a
1
t
i
H
i
1
SCAN
POINTS
++
Fig. 5-8
The
starting
point
in
auto
tuning
modes
may
either
be
a
broadcast
receiving
point
or
a
point
where
no
broadcast
is
received.
Since
stopping
the
scan
merely
at
an
{H]
level
of
the
auto-stop
signal
may
therefore
cause
nonconform-
ities,
the
process
employed
is
to
stop
scanning
only
when
the
auto-stop
signal
has
first
dropped
to
an
{L]
level
after
the
scanning
start
and
then
has
climbed
to
an
[H]
level.
The
scanning
speed
is
about
100
msec
per
step.
The
step
will
be
a
single
channel
spacing
in
the
receiving
band
that
varies
by
destination.
Auto-scanning
of
LW,
however,
is
an
exception
to
this
rule
and
9
kHz
steps
have
been
assigned
to
it,
where
fixed
points
ON+2
or
ON
(N
=
an
integer)
will
be
scanned.
In
other
words,
against
any
given
point
selected
earlier
by
a
manual
scan,
the
scanning
start
when
an
auto-scanning
mode
is
engaged
will
always
be
at
a
point
9N+2
or
9N.
ont2
gintlee
Bin
422
Qn
Q(ntl)
START
9(n+2)
STATION 5-2-8 Key Processing
(1) [BAND]
Each
single
press
of
this
key
will
switch
the
band.
The
selecting
sequences
will
be
as
follows:
2-
BAND
3-
BAND
FM—>AM
FM
MW
—>LW
Fig. 5-11
(2) [UP], [DOWN]
In
a
manual
scan
mode,
each
single
pressing
of
either
of
these
keys
will
shift
the
receiving
frequency
bya
step,
and
its
continuous
depression
will
have
the
band
scanned
at
50
msec
per
step.
In
a
AUTO
scan
mode,
the
band
will
be
scanned
at
100
msec
per
step
until
a
station
is
captured,
at
which
time
an
auto-stop
of
the
scanning
will
be
exercised.
In
an
auto-scan
mode,
as
soon
as
any
other
key
than
(UP]
and
[DOWN]
is
pushed,
the
scanning
will
be
stopped
at
that
point.
O(nt 342
9(nt3)
[anata
ke
as
GL
ices
12
O
SERVICE
MANUAL
AA-A35
[Lee
Fig. 5-9

(3) Preset CH Key
a) When the Tuner is in an Active Mode:
Except when at standby for storage, a single
pressing of one of the preset channel keys will load
the front (1 to 8) and back (9 to 16) side channels
under that key alternately, and the FLD will
display the number of the channel thus loaded.
When at standby for storage, the frequency
currently being received will be stored in either the
front (1 to 8) or back (9 to 16) side memory until
under the key that has been pushed, and the
storage standby mode will then be disengaged.
b) When the Tuner is in a Non-Active Mode:
A push of one of the keys will have the front side
preset channel (1 to 8) under that key loaded, and
have data transmitted to the microcomputer of
AMP to switch the input selector of AMP to
TUNER.
However, when in the last active mode of the
tuner, a back side (9 to 16) channel had been
listened to, and that channel key is now pushed,
the loading effected will not be that of the front
side (1 to 8) but of the back side (9 to 16)
channel.
(4) [MEMO 1 — 8], [MEMO 9 — 16]
These are the keys for storing a channel frequency
data in the Preset CH, and used for channels 1 to 8
and 9 to 16, respectively. Specifically, when either of
the keys is pushed, the MEMO Indicator will be lit,
and the channel number display flashed on and off,
to alert the operator as to which side of the Preset
CH key, 1 to 8 or 9 to 16, is being operated.
For | to 8: For 9 to 16:
preset
Starion\ VT 17
“EVAN
Fig. 5-12
The above mode will be sustained for 5 seconds, and
the flashing repeated for 10 times at a 1/2 duty.
When, however, the Preset CH key is pushed for data
storage, or when any other key is pushed, the storage
standby mode will be instantly disengaged.
When the tuner is in a non-active mode, nothing will
occur.
@)
[MODE] $
Each single pressing of this key will switch the FM
reception between MONO and STEREO from one to
the other.
When the tuner is in a non-active mode, nothing will
occur.
(6) [SCAN’MODE]
Each single pressing of this key will switch the scan
mode between AUTO and MANUAL from one to the
other, and due indications made at the same time.
SERVICE MANUAL AA-A35/L:
13

Vi. AMPLIFIER SECTION ADJUSTMENT
6-1 THE INSTRUMENT CONNECTION
AC VOLTMETER
INPUT(CD)
DUMMY. RES! AC VOLTMETER
Fig. 6-1 Instrument Connections for Amplifier Section Adjustment
6-2. MAIN AMP PC BOARD ADJUSTMENT POINTS
FRONT
t
VARTICAL Pca —>.
(CN INCREASE
Fig. 6-2 Main-Amp PCB
6-3 POWER LEVEL METER ADJUSTMENT Supply 1 kHz to CD input jacks (both left and right CH)
Set DIRECT ACCESS VOLUME (MEMBRAN VOL- and adjust OSC output so that the AC voltmeters
UME) to maximum and TONE control to flat. indicate 15.5V. AdjustVR1 so that the POWER LEVEL
meter indicates 30W.
SERVICE MANUAL AA-A35/L:
14

Vil. TUNER ADJUSTMENT
7-1 THE INSTRUMENT CONNECTIONS
APPROX
600mm
TEST LOOP
ANTENNA
\
|
SET
AC
AM
SSG
VOLTMETER
of
OUTPUT
o4
Leh OR Reh O
OUTPUT
ro
Fig.
7-1
Instrument
Connections
for
AM(MW,
LW)
Section
Adjustment
FREQUENCY
COUNTER
© ANTENNA
TERMINAL
AC
VOLTMETER
FM STEREO DISTORTION
GENERATOR METER
OUTPUT
Fig. 7-2 Instrument Connections for FM Section Adjustment
SERVICE
MANUAL
AA-435[{>_————————————
15

a
7-2.
TUNER,
FRONT
END,
MPX
PC
BOARD
ADJUSTMENT
POINTS
VC2:LW SENS(HIGH)
AM(MW)
SENS(LOW)
2
ed @)
vei ®
@)
FM
SENSI
AM
(MW)
{HIGH}
SENS (HIGH)
vCcl
(HIGH)
FM SENS (LOW)
FRONT END PCB
FM
SENTER
1
L6
VOLTAGE
4
FM
osc
FM
STEREO
a
DISTORTION
@)
FM LOCAL OUTPUT
TP2 a
S
Tel
~G====3
ia
1c4
TPS
To6IO2ZP
AM LOCAL
st)
FM
CENTER
VOLTAGE
OUTPUT
FM DISTORTION
TUNING VOLTAGE
(FM, AM(MW), LW,
osc)
MPX PCB
FM STEREO
SEPARATION
MPX FREE
RUNNING FREQ
RUNNING FREQ
(9kHz)
77
FINCREASE
Lh
TUNER
PCB
FRONT
Fig. 7-3
SERVICE
MANUAL
AA-A35/L
—_—_———_—
rr.
OOO
16

7-3. HOW TO CALL THE PRESET FREQUENCY FOR THE TUNER ADJUSTMENT
Tuner preset frequencies for adjusting RF, IF and FM
demodulator are able to preset as follows insted of
operating TUNING control button to get the test
CONTROL PCB
frequencies from Signal Generator.
SHORT (MOMENTARILY)
Fig. 7-4
Short-circuit_ momentarily two test points shown in
Fig. 7-4. Then select required test frequency by pushing
one of the Preset Station buttons according to Chart 7-1.
NOTE: For {U] model only, set AM STEP switch to 9kHz position, which located on the rear panel.
SERVICE MANUAL AA-A35/L:
PRESET STATION CH
Buttons
& 1/9 2/10 3/11 4/2 5/13 6/14 Ns 8/16
Seren AM AM AM FM FM FM FM FM
600kHz | 1000kHz | 1400KHz | 88.0MHz | 90.0MHz | 98.0MHz | 106.0MHz_| 108.0MHz
USA & CANADA
eae AM AM AM FM FM | * FM rM FM
530kHz | 1000kHz } 1611kHz | 87.4MHz | 90.0MHz | 98.0MHz | 106.0MHz| 108.1MHz
er MW MW MW FM FM FM FM EM
603kHz | 999kFz | 1404kEz | 88.0MHz | 90.0MHz | 98.0MHz | 106.0MHz| 108.0MHz
EUROPE 3 BAND
oie MW MW MW LW LW Lw LW LW
2. 522kHz | 999kHz | 1611kHz| 146kHz | 160kHz | 200kHz | 300kKHz | 353kHz
he8 AM AM AM FM FM FM PM FM
EUROPE 2 BAND 603kHz | 999kHz | 1404kxz | 88.0MHz | 90.0MHz | 98.0MHz | 106.0MHz_| 108.0MHz
UNIVERSAL AREA sie AM AM AM FM FM | * FM FM FM
i 522kHz | 999kHz | 1611kHz | 87.4MHz | 90.0MHz | 98.0MHz | 106.0MHz| 108.1MHz
_
EA AUTO Chart 7-1
17

7-4
FM
SECTION
ADJUSTMENT
|
Remarks
Step
|
Adjustment
Item
Adjustment
Point
Result
Band
SW
to
FM
L6
108.1MHz
Mono
input.
!
FALOSe
(in
FRONT
ENDPcB)
|
?V*
108.1MHZ
|
Display
to
108.1MHz.
Connect
DC
Voltmeter
to
TP2.
FM
mode
SW
to
Mono
2
Low
Range
L1
to
LS
Less
than
10dB
90MHz,
Mono
input.
Sensitivity
(in
FRONT
END
PCB)
input
from
SSG
Display
to
90MHz.
3%
Distortion
Factor.
L
High
Range
VC1,
2,4
Less
than
104B
Seay
a
dnenie
Sensitivity
(in
FRONT
END
PCB)
input
from
SSG
3%
Distortion
Factor.
4
For
best
Result,
Repeat
Steps
2
and
3
two
or
three
times
Middle
Range
98MHz,
Mono
input.
5
Sensitivity
None
i
boii
a
Display
to
98MHz.
(Confirmation)
a
aa
3%
Distortion
Factor.
FM
DC
Voltmeter
between
TPS
and
TP6,|
6
17,78
OV
indication
Tune
only
noise
without
inter-
Center
Voltage
?
ference
from
broadcasting.
98MHz,
60dB,
Mono
input.
Display
to
98MHz.
7
Distortion
(Mono)
17,78
Less
than
0.3%
Confirm
that
the
DC
Voltage
between
TPS
and
TP6
is
within
0+0.025V.
MPX
98MHz,
60dB
Stereo
input.
3
|
Free
Running
VRE.
19kHz
Display
to
98MHz.
Frequenc
(in
MPX
PCB)
Connect
Frequency
Counter
to
ees
TP7
(in
MPX
PCB).
98MHz,
60dB,
Stereo
L-CH
"7
VRI
(R-CH)
input:
9
Stereo
Separation
(in
MPX
PCB)
More
than
38dB
Display
to
98MHZz.
Minimum
output
of
R-CH
(L-CH)
98MHz,
60dB
Stereo
(L-CH
or
Tl
R-CH)
input.
7
rt
1
Display
to
98MHz.
10
|
Distortion
(Stereo)
|
(in
eyes
a
PCB),
Less
than
0.5%
Confirm
that
the
DC
voltage
°
between
TPS
and
TP6
within
0+0.025V.
NOTES:
1.
Set the
internal
modulation
signal
generator
to
1
2.
Adjust
Tl
(Front
End),
if
the
proper
distortion
SERVICE
MANUAL
AAA3S
[LS
18
Sensitivity
in
case
is
turned
more
than
a
half
turn).
00%
(75kHz
dev.
(in
Europe)
40kHz
dev.),
1kHz
of
each.
(STEREO)
could
not
obtained
in
step
10.
(Confirm
FM