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