Akai AM-M459 User manual

AKAT servic
STEREO INTEGRATED AMPLIFIER AM-M459
VOLUME {-¢81
MUTING REMOTE SENSOR
TREBLE
DAT VOR
SOURCE DIRECT
DAT/VCR
WIRELESS REMOTE CONTROL SYSTEM
MOTOR DAIVE VOL UME CONTROL
AKALT one wrecrsten aveunen aves
VOLUME (-a8)
POWER MUTING REMOTE SENSOR
Co =
PHONES TREBLE BALANCE
SOUACE DIRECT
DAT/VCR
DIGITAL SOPTICAL INTERFACE SYSTEM
DIGIT. FiGH GUALITY O/A CONVERTER
MODEL AM-M659
STEREO INTERGRATED AMPLIFIER
MODEL AM-M45
DIGITAL INTERGRATED AMPLIFIER
mon. AM-M659

*
SAFETY
INSTRUCTIONS
a
sh
Ss
es
es
=
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
(transform-
ers,
power
cords,
noise
blocking
capacitors,
etc.),
wrap
ends
of
wires
securely
about
the
terminals
before
soldering.
St
©
oe
ol
6.
Observe
that
wires
do
not
contact
heat
producing
parts
(heatsinks,
oxide
metal
film
resistors,
fusible
resistors,
etc.).
*
INFORMATION
7.
Check
that
replaced
wires
do
not
contact
sharp
edged
or
pointed
parts.
8.
Also
check
areas
surrounding
repaired
locations.
9.
Use
care
that
foreign
objects
(screws,
solder
droplets,
etc.)
do
not
remain
inside
the
set.
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
M
ohms,
but
for
equipment
with
external
antenna
terminals
(tuner,
receiver,
etc.)
and
is
intended
for
or
,
Specified
insulation
resistance
should
be
head-
phone
jacks,
line-in-out
jacks,
etc.
more
than
2.2
M
ohms
(ground
terminals,
microphone
jacks).
PRECAUTIONS
FOR
LITHIUM
BATTERY
The
lithium
battery
may
explode
when
heated
excessively.
[OBSERVE
THE
FOLLOWING
WHEN
REPLACING]
@
Replace
with
the
same
make
and
type
only.
@
Use
soldering
iron
in
“recommended
way”
only.
@ Place battery in correct polarity.
®@ Do not short the terminals.
@ Do not recharge battery.
@ Do not dispose of battery in fire.
[DANGER]
[RECOMMENDED
WAY]
SYMBOLS
FOR
PRIMARY
DESTINATION
Alphabet
indicates
the
destination
of
the
units
as
listed
below.
Symbols Principal Destinations
[A] USA
[a] | vuK
[c] i Canada
LE] Europe (except UK)
[3] Japan
[s] [ Australia
[Vv] W. Germany only
[u] Universal Area
fy Custom version
VOLTAGE
CONVERSION
([U]
Model
only)
Before
connecting
the
power
cord,
SET
the
VOLTAGE
SELECTOR
located
on
the
rear
plate
with
a
screw-driver
so
that
the
correct
voltage
is
indicated.
nn,
SERVICE
MANUAL
—————_—_

I. SPECIFICATIONS
1-1 MODEL AM-M459
Power output by DIN
(1kHz, 8 ohms) 40W + 40W
Music Power
Power bandwidth
S/N (THF-A)
PHONO MM
TUNER etc
Residual noise
Channel separation
5Hz ~ 80kHz/0.1%
Damping Factor
(1 kHz, 8 ohms)
Required speaker
impedance 8 ~ 16 ohms
Input sensitivity/
impedance
PHONO MM 2mV/47kohms
TUNER etc 150mV/47kohms
PHONO max input level
Frequency response
eigutiticesares +0.5dB (RIAA)
TUNER etc 10Hz ~ 50kHz
(-3dB, at source direct)
Tone control
Bassiics cis ethisecsetes +8.5dB at 100Hz
Treble ..................5 +8.5dB at 10kHz
DC power supply
(for PHONO) 12V (center—)
Power requirements 220V, 50Hz for Europe
except UK
240V, 50Hz for UK and
Austraria
110V/220V/220V/240V,
50Hz/60Hz
Convertible for other countries
Power consumption 145W for model
Dimensions 350 (W) X 136 (H) X 360 (D) mm
Standard accessories
Wireless remote control
Dry batteries (R6, DC1.5V)........ sadebesoesen x 2
* For improvement purposes, specifications and design are subject to change without notice.
1-2 MODEL AM-M659
Power output by DIN
(1kHz, 8 ohms)... .. 55W + 55W
Music Power
Power bandwidth
S/N (THF-A)
PHONO MM
TUNER etc
Residual noise
Channel separation
Damping Factor
(1 kHz, 8 ohms)
Required speaker
impedance 8 ~ 16 ohms
Input sensitivity/
impedance
PHONO MM 2mV/47kohms
TUNER etc 150m V/47kohms
Digital input level
(CD-OPTICAL) —22 dBm
PHONO max input level
Output level/impedance
150 mV/1 kohms
Frequency response
dena Conetehasutes +0.5dB (RIAA)
TUNER etc 10Hz ~ 50kHz
(-3dB, at source direct)
Tone control
+8.5dB at 100Hz
Treble ................000 +8.5dB at 10kHz
Power requirements 220V, 50Hz for Europe
except UK
240V, 50Hz for UK and
Austraria
110V/220V/220V/240V,
50Hz/60Hz
Convertible for other countries
Power consumption 185W for model
Dimensions 350 (W) X 137 (H) X 360 (D) mm
Standard accessories
Wireless remote control
Dry batteries (R6, DC1.5V)...
* For improvement purposes, specifications and design are subject to change without notice.
SERVICE MANUAL
w
pliers sae ahs:

I. CONTROLS
ss
sn
2-1 MODEL AM-M459
VOLUME (-aB!
©
9090
@ POWER Button
To turn the power on and off.
@ MUTING Indicator
Lights
when
the
remote
control’s
MUTE
button
is
turned
on.
The
vo-
lume
is
attenuated
by
—20
dB
fromthe
set volume level.
~ © REMOTE SENSOR Window
The
signals
from
the
remote
control
are received by this window.
Keep this window clean.
@
VOLUME
Control
and
Indicator
(Mo-
tor
driven
for
remote
control
opera-
tion)
To adjust the volume level.
©
Input
Source
Indicators
(TUNER,
PHONO,
CD,
TAPE,
DAT/VCR)
Tells
you
the
amplifier
is
turned
on
and
which
playback
source
is
select-
ed.
@
SOURCE
DIRECT
Button
and
Indi-
cator
When
engaged,
the
input
signal
by-
passes
the
BASS,
TREBLE
and
BAL-
ANCE
control
for
optimum
sound
quality
playback.
The
indicator
lights
when
the
SOURCE
DIRECT
button
is
turned
on.
@ Input Select Buttons (TAPE, DAT/
VCR, TUNER, PHONO, CD)
To select a playback or recording
source you wish to listen to.
© BALANCE Control (LEFT/RIGHT)
To adjust the left and right channel
volume balance.
© TREBLE Tone Control
To adjust the high note (treble) level.
When set to 0, the control has no ef-
fect.
wrecess/emMore contac </stem
moron Juve vo.ume CONT) x
AY
@® BASS Tone Control
To
adjust
the
low
note
(bass)
level.
When
set
to
0,
the
control
has
no
ef-
fect.
@ PHONES Jack
Connect
the
headphones
plug
to
this
jack for private listening.
When
connecting
the
plug,
the
speaker
output
will
be
cut
automati-
Cally.
=
SERVICE
MANUAL;
—————=——
4

2-2 MODEL AM-M659
fi | err. man Guapry o/a conven/en
®o oo
@ POWER Button
To turn the power on and off.
@ MUTE Indicator
Lights when the MUTE button of the
remote control unit is turned on. The
volume is attenuted by —20 dB (to
1/10).
© Remote Sensor Window
The signals from the remote control
are received by this window.
Keep this window clean.
@ DIGITAL Indicator
Tells you the amplifier is in the CD
mode. In this case, playback signals
are received at the digital input.
© VOLUME Control
To adjust the volume level.
DIGITAL INTEGRATED AMPLIFIER AM-M659
3)
© Input Source Indicators (TAPE,
DAT/VCR, TUNER, CD, PHONO)
Tells you the amplifier is turned on
and which playback source is select-
ed.
@ SOURCE DIRECT Button and Indi-
cator
When engaged, the input signal by-
passes the BASS and TREBLE tone
controls for optimum sound quality.
The indicator lignts when the
SOURCE DIRECT button is turned
on.
© Input Select Buttons (TAPE, DAT/
VCR, TUNER, CD, PHONO)
To select a playback or recording
source you wish to listen to.
© BALANCE Control (LEFT/RIGHT)
To adjust the volume balance of the
left and right channels.
SERVICE MANUAL
9e9o 9
Gexer] ongl[_co_]
| CCA)
0 0
@ TREBLE Tone Control
To adjust the high note (treble) level.
When set to 0, the control has no ef-
fect.
@ BASS Tone Control
To adjust the low note (bass) level.
When set to 0, the control has no ef-
fect.
@ PHONES Jack
Connect the headphone plug to this
jack for private listening.
When connecting the plug, the
speaker output will be cut automati-
Cally.

ill. DISASSEMBLY
eee
In
case
of
trouble,
etc,
necessitating
dismantliag,
please
dismantle
in
the
order
shown
in
the
photographs.
Reassemble
in
reverse
order.
*
Photographs
employed
in
this
paragraph
are
model
AM-M659
1. Removal of UPPER COVER
2 “Seca
FIXING
NUTS
a ali
a [ese
FRONT
PANEL
x
KNOBS
%
REMOVE
THE
FOUR
KNOBS,
| AND REMOVE FOUR VOLUME
FIXING NUTS.
j
=
2. Removal of FRONT PANEL
and BOTTOM COVER
4. Removal of CONTROL PCB
i] FRONT PANEL
FRONT
PANEL
y
CONTROL
PCB
BOTTOM COVER
m=
SERVICE
MANUAL
———————___
6

IV. PRINCIPAL PARTS LOCATION
4-1 MODEL AM-M459
POWER SW PCB
POWER TRANSFORMER
T501 MAIN PCB
PHONE PCB CONTROL PCB REMOTE PCB | VOLUME PCB
LED PCB
Fig 4-1
SERVICE MANUAL
3
|

a
4-2 MODEL AM-M659
POWER SW PCB
POWER TRANSFORMER
T501
MAIN
PCB
D/A
PCB
PHONE
PCB
CONTROL
PCB
REMOTE
PCB
VOLUME
PCB
LED PCB
Fig 4-2
nem
SERVICE
MANUAL
FS
eS

V. ADJUSTMENT (model Am-mM659 only)
5-1 ADJUSTMENT OF PLL CIRCUIT
NOTE: When adjusting step 1 (VCO CONTROL VOLTAGE), Remove the Shield cover before adjustement.
8
REAR
VIEW FROM
PARTS SIDE
CONTROL |
LTAGE, ——~)
ADy 145}! IC 1
(a5)
D/A PCB
Fig 5-1 Test and adjustment Point
Adjustment . Adjustment
Item Test. Point Point Result and Remarks
e Connect the CD player (at STOP mode) which has OPTICAL
OUTPUT such as CD-M659 to CD OPTICAL INPUT.
e Connect an oscilloscope to TP.CV and adjust C2 (CONTROL
VOLTAGE ADJ) so that the voltage on the oscilloscope is
DC2.4 V to 2.5 V as in Fig 5-2
VCO
CONTROL
VOLTAGE
Fig. 5-2
e Connect the CD player (at STOP mode) which has OPTICAL
OUTPUT such as CD-M659 to CD OPTICAL INPUT.
e Connect an oscilloscope to TP.VAR and adjust VR1 (PLL ADJ)
so that the timing of waveform on the oscilloscope is 50ns as in
Fig 5-3.
SERVICE MANUAL

VI.
PARTS
LIST
HOW
TO
USE
THIS
PARTS
LIST
1.
This
Parts
List
lists
those
parts
which
are
considered
necessary
for
repairs.
Other
common
parts,
such
as
resistors
and
capacitors,
are
listed
in
the
“Common
List
for
Service
Parts”
from
which
these
parts
should
be
selected
and
stocked.
2.
The
Recommended
Spare
Parts
List
shows
those
parts
in
the
Parts
List
which
are
considered
particularly
important
for
service.
3.
Parts
not
shown
in
the
Parts
List
and
“Common
List
for
Service
Parts”
will
not
in
principle
be
supplied.
4.
How
to
read
the
Parts
List.
a)
Mechanism
Block
b)
PC
Board
2.
HEAD
BASE
BLOCK
6.
MAIN
PC
BOARD
REF
REF.
No.
PART
NO.
DESCRIPTION
No:
PART
NO.
DESCRIPTION
2-1x
BH-T2023A320A
HEAD
BASE
BLOCK
6-IC1
EI-324536
IC
HD14049BP
2-2
HP-H2206A010A
HEAD
R/P
PR4-8FU
C
6-IC2
_—_—EI-336801
IC
MB8841-564M
2-3
ZS-477876
PAN20x03STL
CMT
6-C1A
—EC-338399|
C
MMY
V
223M
250AC
[U,E,B,S]
2-4
ZS-536488
BID20x08STL
CMT
6-C1B
EC-350949|
=
C
MMY
V
223M
250DC
[J]
2-5
ZG-402895
SP
CS
ANGLE
ADJUST
6-C1C_
—_
EC-338397_
C
MMY
V
223M
125AC[C,A]
\
6-X1
EI-318384
OSC
X’TAL
NC-18C
SP
(Service
Parts)
Classification
Symbols
for
primary
destination
A
small
“x”
indicates
that
this
part
is
not
[A]:
AAL(U.S.A.)
[S]:
SAA
(Australia)
shown
in
the
Photo
or
IIlustration
(B]:
BEAB(England)
[U]:
U/T(Universal
Area)
:
[C]:CSA(Canada)
[V]:
VDE(W.
Germany)
———
This
number
corresponds
with
the
indi-
[E]:CEE(Europe)
[Y]:Custom
Version
vidual
parts
index
number
in
that
figure.
[J]:
JPN(Japan)
This
number
corresponds
with
the
Figure
SP
(Service
Parts)
Classification
Number.
These
reference
symbols
correspond
with
component
symbols
in
the
Schematic
Diagrams.
The
available
PC
Board
Blocks
are
listed
separately.
5.
When
Part
No.
is
known,
Parts
Index
at
end
of
Parts
List
can
be
used
to
locate
where
that
part
is
shown
in
Parts
List
by
its
Reference
No.
listed
at
right
of
Part
No.
CONTINUED
§
LACE
SAFETY
i
£.
POUR
MAINTENIR
LE
DEGRE
TECES
RECOMMANDEES
PAR
LE