Akai GX-630D User manual

SEAM
AKAI
STEREO
30D
DEC
moos G> -_
(-630

AKAI STEREO TAPE DECK
mopeL GX-630D
ALSO APPLICABLE TO MODEL GX-630DB STEREO TAPE DECK
SECTION 1 SERVICE MANUAL ............ 0. ccc eee ee eeee 1
SECTION 2 PARTS LIST ........... 0... cece eee eee 25

I.
SPECIFICATIONS
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2
Il.
DISMANTLING
OF
UNIT
......
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4
Ill.
ARRANGEMENT
OF
PRINCIPAL
PARTS
........
0.0
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ett
ees
5
IV.
MECHANISM
ADJUSTMENT
........
2.000
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6
1.
POSITION
ADJUSTMENT
OF
BRAKE
SOLENOID
SL-2
...
2...
eee
es
6
2.
BRAKE
TENSION
ADJUSTMENT
....
0.00.
ee
6
3.
POSITION
ADJUSTMENT
OF
PINCH
ROLLER
SOLENOID
SL-1
........---
+++
eee
uee
7
4,
PINCH
ROLLER
PRESSURE
ADJUSTMENT
.....
0...
00
eee
tee
7
5.
CAPSTAN
SHAFT
LOOSE
PLAY
ADJUSTMENT
.......---
0
eee
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ees
q
6.
IMPEDANCE
ROLLER
LOOSE
PLAY
ADJUSTMENT
.....
16...
.
eee
eee
eee
ees
7
7.
TAPE
GUIDE
HEIGHT
ADJUSTMENT
......-
2.
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es
8
8.
REEL
TABLE
HEIGHT
ADJUSTMENT
.....
0.2.6
ee
eee
es
9
9.
INSTALLATION
POSITION
ADJUSTMENT
OF
JOINT
B....
6...
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ees
9
V.
HEAD
ADJUSTMENT
.........
0-0
cee
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ee
nee
10
VI.
AMPLIFIER
SYSTEM
ADJUSTMENT
...... 2.2.2.
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tens
2
1.
D.C
POWER
SUPPLY
VOLTAGE
ADJUSTMENT
......---
00
ee
eters
2
2.
TAPE
SPEED
ADJUSTMENT
.....
2...
ee
es
ip)
3.
RECORDING
AND
PLAYBACK
AMPLIFIER
ADJUSTMENT
(GX-630D)
.........-.----
B
4.
RECORDING
AND
PLAYBACK
AMPLIFIER
ADJUSTMENT
(GX-630DB)
...........---
4
5.
DOLBY
NOISE
REDUCTION
ADJUSTMENT
(GX-630DB)
....
6.6...
sere
e
eee
5
VII.
D.C
RESISTANCE
OF
VARIOUS
COILS
..
1...
2...
ee
ee
es
6
VIII.
CLASSIFICATIONS
OF
VARIOUS
P.C
BOARDS
.....
2.2...
0
cece
7
1.
P.C
BOARD
INTERCHANGEABILITY
CHART
....
0.2...
ee
ees
7
2.
COMPOSITE
VIEWS
OF
VARIOUS
P.C
BOARD
....
2-6-0
2
7
SECTION 1
SERVICE MANUAL
TABLE OF CONTENTS
For
basic
adjustments,
measuring
methods,
and
operating
principles,
refer
to
GENERAL
OPERAT-
ING
PRINCIPLES
AND
ADJUSTMENTS.

| SPECIFICATIONS
An asterisk next to a figure indicates the minimum guaranteed performance.
TRACK SYSTEM
4 track 2 channel stereo/monaural system
TEPE SPEED
7-1/2 and 3-3/4 ips +0.7%
*7-1/2 and 3-3/4 ips +1.0/—1.5%
WOW AND FLUTTER
Less than 0.06% WRMS at 7-1/2 ips
Less than 0.09% WRMS at 3-3/4 ips
*Less than 0.10% RMS at 7-1/2 ips
*Less than 0.15% RMS at 3-3/4 ips
TOTAL WOW AND FLUTTER
*Less than 0.12% RMS at 7-1/2 ips
*Less than 0.18% RMS at 3-3/4 ips
FREQUENCY RESPONSE
30 to 25,000 Hz +3 dB at 7-1/2 ips
30 to 19,000 Hz +3 dB at 3-3/4 ips
(with AKAI LN-150-7 Tape)
| *30 to 22,000 Hz +3 dB at 7-1/2 ips
i *30 to 18,000 Hz +3 dB at 3-3/4 ips
HARMONIC DISTORTION
Less than 0.5%
TOTAL HARMONIC DISTORTION
al *Less than 1.5%
SIGNAL TO NOISF RATIO
Better than 50 dB
TOTAL SIGNAL TO NOISE RATIO *Better than 47 dB
| *0.775V (0 dBm +1.0 dB)
30 mV at 8 ohm
At playback of a 700 Hz “0” VU pre-recorded test tape.
| (Output Volume at maximum)
OUTPUT LINE
HEADPHONE
INPUT MIC
LINE
DIN INPUT/OUTPUT
RECORDING/PLAYBACK LEVEL
CROSS TALK
ERASE RATIO
RECORDING BIAS FREQUENCY
BIAS LEAK -
HIGH FREQUENCY DEVIATION
More than 0.25 mV/10 k ohm
More than 70 mV/150 k ohm
At “0” VU output. (Recording Volume at maximum)
0.25 mV/0.5V
*0.775V (0 dBm +1.5 dB)
Better than 45 dB, stereo
Better than 55 dB, monaural
Bec
RECORDING TIME
| Better than 70 dB
100 kHz +5%
Better than —30 dB (GX-630D)
Better than —50 dB (GX-630DB)
Within 3 dB
At playback of an 8,000 Hz 3-3/4 ips pre-recorded tape at 7-1/2 ips
180 min stereo recording at 7-1/2 ips, using a 3,600 ft tape.
F.FWD AND RWD TIME
Approximately 2 min and 40 sec at 50 Hz, using a 3,600 ft tape.
MOTOR
MAIN MOTOR
REEL MOTOR
2 speed AC servo control outer rotor motor
Type: SCM2-24K]J 4 pole
Revolutions: 615 rpm at 7-1/2 ips (19 cm/sec)
307.5 rpm at 3-3/4 ips (9.5 cm/sec)
6 pole eddy current outer-rotor motor
| Type: 24X0-TD
Revolutions: 930 rpm at 50 Hz
1,120 rpm at 60 Hz
HEAD
ERASE HEAD
RECORDING HEAD
PLAYBACK HEAD
Type: E4-260
Gap: double gap
Impedance: 210 ohm +10% at 100 kHz
D.C Resistance: 2 ohm
Type: R4-200
Gap: 4 micron
Impedance: 1,870 ohm at 100 kHz
| D.C Resistance: 8 ohm
_ Type: P4-202
; Gap: 1.7 +0.5 micron
! Impedance: 1,400 ohm at 1 kHz
D.C Resistance: 268 ohm

TRANSISTOR
&
FET
2SA564(Q)(R)
.
.
.
1(5)
2SC1247A(B)(Y)
..
.
2(2)
2SC458(C)
..
.
0(12)
2SD361(D;)(D2)
...
1(1)
2SC458LG(C)
.
.
.
16(32)
TIP47
...1(1)
2SC711(F)(G)
..
.
2(2)
2SK30A(GR)
.
.
.
0(4)
2SC945L(Q)(P)
.
. .
22(22)
DIODE
1N34A
...
2(6)
10D2...4(4)
1N4001...
4(4)
WZ075
..
.
2(2)
1N4004
..
.
6(6)
WZ08S5
..
.
0(4)
181588...
11)
WZ192...10)
182473...
21(21)
RDSA(M)
..
.
1(1)
182473VE ... 16(28)
POWER REQUIREMENT AND CONSUMPTION
100 to 240V AC 50/60 Hz, 90W (Universal Models)
220V AC 50 Hz, 100W (CEE Models)
120V AC 60 Hz, 90W (CSA Models)
100V AC 50/60 Hz, 70W (JPN Models)
ee
DIMENSIONS
465(H)
x
440(W)
x
240(D)
mm
(18.3”
x
17.4”
x
9.4”)
Dimensions
include
all
protruding
parts.
WEIGHT GX630D: 19 kg (41.8 Ibs)
GX-630DB: 19.5 kg (42.9 Ibs)
NOTES: 1. Specifications determined with SCOTCH #211 Tape unless otherwise noted.
2. Specifications subject to change without notice.
3.
The
numbers
shown
in
parentheses
in
Items
TRANSISTOR
&
FET
and
DIODE
are
applicable
to
Model
GX-630DB.

li DISMANTLING OF UNIT
In
case
of
trouble,
etc.
necessitating
disassembly,
please
disassemble
in
the
order
shown
in
photographs.
Reassemble
in
reverse
order.
r
bo
SCREWS

li!
ARRANGEMENT
OF
PRINCIPAL
PARTS
RR
BRAKE HOLD MICRO
SWITCH SW-8, SW-9
BRAKE SOLENOID
SL-2
PINCH ROLLOR
SOLENOID SL!
|'MPEDANCE
ROLLER
HEAD
BLOCK
TENSION MICRO
REEL
SIZE
SW-3
SWITCH
SW-7
TAPE SPEED SW-2 PAUSE MICRO SWITCH
sw-5
POWER SW-!
REEL SIZE SW-4 PUSH BUTTON
MONITOR
SW-!
PAUSE
MICRO
SWITCH
Ssw-6
RIGHT REEL MOTOR
24X0-TD
LEFT REEL MOTOR
24xX0- TD
srmaseen
SERVO PC BOARD
My
Obes
RELAY
RC
BOARD
TE-2002
MAIN MOTOR
SCM2-24KJ
SYS-CON P.C_BOARD
TE- 200!
PB AMP RC BOARD
REC AMP P.C BOARD
MY -5016 MY- 5017

IV MECHANISM ADJUSTMENT
SPRING RACK MICRO SWITCH SW-8, SW-9
BRAKE LEVER SPRING BRAKE BAND LEVER
ced ~ “a RA
BRAKE LEVER B Gaal Sealy
ae
BRAKE SOLENOID SL~-2 | | BRAKE BAND LEVER
BRAKE BAND SUPPORT BRAKE BAND SUPPORT
Y
BS
BRAKE LEVER A
Fig. 1
BRAKE DRUM
BRAKE BAND GUIDE
BRAKE LEVER
CLOTH TAPE
BRAKE BAND
BRAKE BAND GUIDE
Fig. 2
1. POSITION ADJUSTMENT OF BRAKE
SOLENOID SL-2 (Refer to Figs. 1, 2)
1) Adjust left/right Brake Band Support positions so
that at stop mode, Brake Lever A and Brake Lever
B display 180° angle relativity.
2) Under the conditions described in 1) above, adjust
installation angle position of Microswitches SW-8
and SW-9 so that the clearance between the brake
- lever and brake band lever is 1.5 mm.
3) Adjust installation position of the Brake Solenoid
so that at playback mode, the brake band sepa-
rates from the brake drum.
2. BRAKE TENSION ADJUSTMENT (Refer to
Figs. 1, 2)
1) Adjust installation position of the Spring Rack so
that brake tension is 500g.
2) After brake tension adjustment, adjust installation
position of the Brake Band Guide so that at all
modes except stop mode, the brake band com-
pletely separates from the cloth tape on the brake
drum.

PINCH ROLLER SOLENOID SL—I
PLUNGER PULL BAR
PINCH ROLLER PRESSURE
ADJUSTMENT NUT 1.4Kg
PINCH ROLLER
Fig. 3
3.
POSITION
ADJUSTMENT
OF
PINCH
ROLLER
SOLENOID
SL-!
(Refer
to
Fig.
3)
1)
Insert
a
4
mm
thickness
gauge
(A
U
type
washer
can
be
substituted)
between
the
Pull
Bar
and
Pinch
Roller
Arm.
SQ
2)
Set
the
deck
to
playback
mode,
and
fix
Pinch
Roller
Solenoid
at
position
at
which
pinch
roller
begins
to
rotate.
THRUST SUPPORT ANGLE
4.PINCH
ROLLER
PRESSURE
ADJUST-
MENT
(Refer
to
Fig.
3)
Adjust
Pinch
Roller
Pressure
Adjustment
Nut
so
that
pinch roller pressure is 1.4 kg.
NOTE:
To
measure
pinch
roller
pressure,
pull
the
pinch
roller
away
from
capstan
with
a
spring
gauge
and
gently
return.
Spring
Gauge
indi-
cation,
at
the
time
the
pinch
roller
contacts
the
capstan
and
the
capstan
begins
to
rotate,
should
be
1.4
kg.
CAPSTAN SHAFT
Fig. 4
5.
CAPSTAN
SHAFT
LOOSE
PLAY
ADJUST-
MENT
(Refer
to
Fig.
4)
Adjust
to
obtain
a
clearance
of
0.1
mm
between
the
Capstan
Shaft
and
Thrust
Support
Angle.
IMPEDANCE
ROLLER
6.
IMPEDANCE
ROLLER
LOOSE
PLAY
AD-
Fig.
5
JUSTMENT
(Refer
to
Fig.
5)
Adjust
Screws
A
and
B
so
that
impedance
roller
loose
play is 0.1 mm.
NOTE:
Confirm
that
the
screws
are
tight
following
this
adjustment.

TAPE GUIDE
TAPE
TENSION ARM
ADJUSTMENT WASHER ADJUSTMENT WASHER Wy)
% LOWER THE GUIDE DOWN A LITTLE % LIFT THE GUIDE UP A LITTLE
Fig. 6
TAPE GUIDE
ADJUSTMENT
WASHER 0.!/t
Qh hndkiddficlhih (LL Lhe
Na
Fig. 7
7. TAPE GUIDE HEIGHT ADJUSTMENT
(Refer to Figs. 6. 7) ;
Adjust tape guide height so that the tape does not
curl between the tape guide and guides on head base.
NOTE: As left and right tape guide height adjust-
ment methods are different. be sure to refer
to Figs. 6, and 7.