Akai GX-230 User manual

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SECTION
I SERVICE
MANUAL
SECTION] PARTS
LIST
SECTION3 SCHEMATICDIAGRA}Í
....
I
23
.tl

I
SECTION
I
SEtrIVICE MAI\ITJAL
TABLE
OF
CONTE\TS
I SPECIFICATIONS
II. DIS\I\NTLING OF UNIT
III. .\RR-\,NGENÍENT
OF TÍAIN PARTS
IV. }fECHANISNÍ
ADJUSTIIIENT
I. .\DJUST}f
ENT OF PINCH\\'HEEL
PRESSURE
]. BRAKE TENSION
ADJUST\IENT
3. .\DJUST\ÍENT
OF REEL
TABLE HEIGHT
.I. .\DJUSTIvÍENT
oF CAPSTAN
\{oToR SHAFT LooSE PL.\Y
.i. .\DJUST}IENT
OF II,IPEDANCE
ROLLER
SHAFT LOOSE
PLAY ,
6. HEIGHT .\DJUSTMENT
OF TAPE
GUIDE
ON TENSION
.{RM
: .\DJUST}IENT OF TENSION
ARN{
\fICROSWITCH
SW-9
POSITION
. .
8. .{DJUST}IENT
OF RECORDING
SLIDE
SWITCH
(SW-IO)
TI\ÍING...
9. .\DJUSTillENT
oF FF MICRoSwITCH
(SW.-s)
.\CTUAToR PoSITION
10. .\DJUST\Í
ENT oF PLAY \ilcRoswtrcH (sw-r ¡nd SW-il r
.\CTIVATOR POSITION
\. HEAD .\DJUST\ÍENT
VI. .\}IPLIFIER SYSTEMADJUSTI\IENT
I PO\\'ER
SUPPLY
VOLTAGEADJUST},ÍENT
:. T\PE SPEED
ADJUSTNÍENT
.
3 RECORDING.
PLAYBAC]K
AMPLIFIER
.\DJUST\IENT
VII. D.C. RESISTANCE
OF VARIOUS COILS
VIII. CLASSIFICATION OF VARIOUS P.C.
BOARDS
I. P
C. BOARD
INTERCIIANGE,\BILITY
CIIART
] CO\IPOSITE
VIEWS
OF ('O\IPONE\TS
[:r.i i'r:lc.idJusin]cnts. ntc.lsLlnngntetltods. lnd opc:-,l:^ltg
prlltelDic's.
rcfer lt.r
(;E\ER.\L OPER.\
fIN(;I'RINCIPI-ES.\\D ,\I)JL'S
f\IENTS
l
-t
6
7
7
¡l
9
9
t0
l0
il
ll
t2
lz
¡3
l5
t5
t5
l6
l7
l7
l7
l8

I
I. SPECIFICATIONS
An astersk next to a figure indicates the minimum guaranteed performance.
TRACK SYSTEM i 4 track 2 channei
stereo
svstem
TAPESPEED 7-ll2and3-314
ips.
x0.7%
*'l-ll2 ips.
(19
crn/sec.)
xl.Mo
*3-3l4
ips.
(9.5
cml
Lessthan0.07%
RMS.
at 7-ll2iPs.
Less
than0.i% RMS.at3-3/4
ips.
*Less
than0.l0Voat 7-Il2 iPs.
FWD
*Less
than0.I2% at'l-ll2 ips.
REV
*
Less
than0.15%
at 3-3 4 ips.
FWD
*Less
than0.l8Vo
at3-3/4
iPs.
REV
*Less
than0J2% at 7-ll2 ips.
*Less
than
0.I8%
at3-314
ips.
30to 23,000Hz
t3 dBat 7-ll2 ips.
lwith Akai LN Tapel
30to 19,000
Hz
t3 dBat3-314
ips.
(with Akai LN Tape)
30to 22.000Hz
t3 dBat
7-ll2 ips.
30
to 18.000
Hz
t3 dB
at3-314
i
Less
than 1.07o
Lessthan 1.5%at 7-ll2 ips.
WOW
& FLUTTER
TOTAL
WOW
& FLUTTER
FREQUENCY
RESPONSE
DISTORTION
TOTAL DISTORTION Lessthan25% at 3-314
i
SiNRATIO Betterthan54dB
*Better
than50
dB
TOTALS/N
RATIO *Betterthan45 dB
OUTPUT LINE 0.775V
(0 t I dB/O
t 1.5
dB.
FWD/REV)
DIN 700Hz "0" VU Prerecorded
tape,
output volumemaximum'
0.5v
INPUT MIC
LINE
DIN
\f ore than 0.3 mV
Morethan 70mV
Morethan3 mV
RECORDING/PLAYBACK
LEVEL
CROSS
TALK
ERASERATIO
RECORDING
BIAS
FREQUENCY
BTAS
LEAK
HIGH FREQUENCYDEVIATION
(at "0" VU output,recording
volumemaximum),
0.775V
(0
t 1.5
dB)
Better than 40 dB
(1,000Hz +3VU recordi
Better than 70dB
(1,000Hz +3VU recording)
100
t 10
kHz
Better
than -30 dB
Within 3 dB
(8,000
Hz. 3-314
ipt. ta
90 minutes.
stereo
recording,
using
a 1,800ft. tape
at 7-ll2 ips'
RECORDING
TIME
FASTFORWARD
AND REWIND
TIME Approxrmately120seconds,
using
a 1.800ft. tape
¿1!9 FIz.
\IOTOR MAIN MOTOR
REEL
}IOTOR
2 speed
A.C.Servo
Conuol Outer Rotor Motor
Type: SCM2-24K1,4
pole
Revolutions:6l5 r.p.m.
at 7'Ll2 ips.
(19
cm/sec.)
307.5
r.p.m.
at 3-314
iPs.
(9.5
cmisec.)
Two 6-pole
eddycurrent
Outer Rotor Motors
Type: 24XGMR
Revolutions:930
r.p.m.
at50 Hz
HEAD COMBINATION
RECORDING/ERASE
HEAD | 1,120
r.p.m.
at
60Hz
Type: RE4-6
Gap: Rec:
4¡¡
Erase:Double
GaP
lmpedance:
Rec:i,400
ohmt25% at 100
kHz
Erase:130
ohm t7% at lO0kÍlz
D.C.Resistance: Rec:
5.5 ohm
Erase:
1.8ohm
Type: P4-202
Gap:1.7¡r
t0.51
Impedance:1,400
ohm at I kHz
D.C.Resistance:
268ohm
PLAYBACK HEAD

I
TRANSISTOR 2SA564(PXQ)
.. . i
2SC4s8LG(C)...16
2SC945(PXO.
..
20
2SC1247A...
I
2SD361(DXE)...1
2SD361(DlXD2)...1
TlP48.
.
.1
DIODE 1N34A...2
10D05...4
toDl
... I
10D2...+
15-1588...
1
ls-2473VE...
r
RD-sA(M)...1
582...1(GX-230only)
10D4...5
STK-015
...2 (GX-230
only)
POWER
SUPPLYANDPOWERCONSUMPTION 100
to240VA.C.
50/60
Hz,90W
Universal
Models
240V
A.C.50
Hz,90W
BSI
Models
220V
A.C.50
Hz.90W
CEE
Models
l20V
A.C.60H2,90W
CSA
Models
100V
A.C.50/60
Hz.
60/65W
JPNModels
RecorderTvoe:
l20W
DIMENSIONS 441(W)x
404(H)
x 210(D)mm
(l'7.4"x15.9"x8.3")
Dimensions
include
ail
GX-230D 15.2
ks
(33.4
lbs.)
cX-230 16.7
ks
(36.7
lbs.)
NOTES: l. Specificaüonsdetermined with Scotch #2ll tape unlessotherwise noted.
2. SpecificationsSubject to changewithout notice.

I
II. DISMANTLING OF UNIT
In caseof trouble, etc. necessitating
ciisassembly,piease
disassemble
in the order shownrn photoeraphs.
Reassemble
in reverse
order.
HEAD
COVER
: ': Ft t=t rftsf ¡
---oII O-O
ffiE
SCREv'jS
:^
iuBBER
-,tlOT i
CONTROL
KNOBS
OO
-RONT
F]\EL D
gt,
-l
I
I
o
NCH ROLLPI ER CAP
ADJU-S-:'If
NT

T
]CNNECTION
PLUGS
{ffi
¡ -tl
q"ffi
_.¿J*i
:?.i
- -
:-f--¡'-
:.RE\,VS AfvlP
BLOCK

I
III. ARRANGEMENTOF MAIN PARTS
FAST
2
:ssiMELY
TENSICN
SiV'9
KEY SUTTCN
ELOCK
"¿¡U5E : 't ó
LEFT REEL
MOTOR
POWER
TRANSFORMER
POWER
S"PPLY
PC.
30ARD 'lY- 2037
s
,r'6
E
,'tt'=
3
-
GFi,
rlf
-
g-
HEAO
BLOCK
a
RIGHTREEL MOTOR
:ERVO:CNTROL EC.
3OARD
MY-2C36
:t ^v c,¡/ ?
iF SW5
VAIN MOTCR
?EC, SW, P
C
BOARD
MY-2044
-'¡sc.
I i5c. a[4P oc,
SOARD
lt'1
r-:-'6
/B 1-
!
I
tü
t#-=
-ñ'
---
.1t--

T
IV. MECHANISM ADJUSTMENT
-BRAKE
LEVERB
BRAKELEVER
A-
_-l8Oo-.
SOLENOI
D
FIXATION SCREWS
''ATSTOP
MOOE
"
Fiq,2
I. ADJUSTNÍ
ENT OF PINCH 1VHEELPRES-
SURE
(Refer
to Figs.I and
2)
I) Unfasten Microswitch (SW4) Activation Adjust-
mentScrewsCandC'.
2) At play mode, confirm that Brake Lever A and
Brake Lever B are placed at a 180" angle in
relation to each other. If necessary,adjust the
angleby changrng
Play Solenoid
(SL-l) position.
3) Adjust prnch
wheel
pressure
to 1.5
t0.l kgr-cmby
re-positioningPlate
A andAngieB.
SCREW
C -
SCREW
CAPSTAN SHAFT
PINCHWHEEL
4) Then,
at stop
mode.
fasten
screws
C andC' sothat
the clearance
between the body of Microswitch
SW4 (with time delay) and the actuator of the
microswitch
isapproximately
0.5 mm asshownin
Fig.2.
@
XO5mm
SPRING
-J
sw-4

I
SOmm-
BRAKE
BANDSUSPENSION
METAL
BRAKE BAND .
2.
BRAKE TENSION
ADJUSTMENT
(Refer
to
Figs.
3and
4)
l) As shown
in Fig. 3, use
a 60mm diameter
tape
wound on a 5" reel and set both left and right
braketension
to approximately
350gr-cm.
Deviationof left and right tensionmustbewithin
50 gr-cm.
2) Brake tension can be adjustedby changingposi-
tion of the Suspended
Spring.
If necessary,
change
Fig.3
METAL
X Confirmthot boih ore
coírpl€loly soporoted Fig.4
the position of the Spring SuspensionMetal or
replacethe spring.
3) At all modes except stop mode, confirm that
neither of the brake bands touch the cloth tape
around the brakedrums.
ERAKE DRUM
A
v

T
REELTABLE
F|XATION
SCREWS
,I
tt
t;/
ñEEL IAELE-
MAIN MOTOR- - IHRUST SUPPORT ANGLE
Fig.
5
3.ADJUST}ÍENT OF REEL TABLE HEIGHT
(Refer
to Fig.
5)
I) Properil' load a tape and move the reei table as
indicaredby the arrowma¡k in Fig.
5.
2) Fasten Reel Table Fixation Screwsto maintain
optimum position at F. FWDandRWDmodes.
NOTE: Tape should wind on centerof reel
resard-
less
of type reel
used.
4.ADJUSTMENT OF CAPSTAN MOTOR
SHAFT LOOSEPLAY
As shownin Fig.6, adjust
theloose
piav by inserting
an adjustmentwasher
(U type) to obtain a 0.3 to
0.5mm degreeof loose
play
whenthecapstan
shaftis
movedby hand.

t
X'O.l
toO.3nm Fig.
7
l=__1_IAPE GUTDE
, 'i--'i t
TENSION ARM
A&JUSTMENT
lfl':,i:
lT'a
slightly \
5.ADJUSTMENT
OF IMPEDANCEROLLER
SHAFTLOOSE
PLAY(Refer
to Fig.7)
Adjust by tuming adjustment screws A and B to
obtain a 0.1 to 0.3 mm degreelooseplay when the
shaftismovedbv hand.
NOTE: Both A andB screws
must be tiehtenedafter
this
procedure.
6.
HEIGHT ADJUSTMENT OF TAPE GUIDE
ON
TENSION
ARM
Adjust the height of Tape Guide on Tension
Arm by
inserting
an adjustment washer(U type) asshownin
Fig. 8 so that tape travelson the center of the tape
euide.
ADJUSTMENT
WASHER(U
TYPE)
X'L¡ff fh€gu¡do
slighlly
Fig.
8
l0

I
Switch Potñi
for mtcroswt?cñ
i-y¡6pg SWTTCH
SWg
(TENSION
SW,)
Fig.9
SLIDESWITCH
.ICTIVATOR
ANGLE
X Bend
lhls
Port r
INTERLOCK
SPRI
NG
REC.PUSH
EUTTON
X lncluding
bock
oIlowonce
7.
ADJUSTMENT
OFTENSIONARM MICRO-
SWTTCH
SW-gPOSITION
Cont'irm
that themicroswitch
operatesat theposition
indicatedin Fig. 9. If necessary,
move the micro-
switchto obtainoptimum position.
8.
ADJUSTMENT
OF RECORDINGSLIDE
SWITCH
(SW.IO)
TIMING
'fu strown in Fig. 10. adjust the switch timing by
bending the slide Switch Activator Angieso that the
slide
switch
slider
just comes
in contact
with the
back
partof theslide
switch.
At this time. the REC Push
Button isfully depressed.
SLIDE SWITCHSLIOER
x.Just contocls
SACK
PART
Fig.
l0
ll

I
F E MICRO SWITCH
(sw-5)
9.ADJUSTMENT OF FF }ÍTCROSIVITCH
(SW.s
) ACTUATORPOSITION
At stop mode.move themicroswitch
actuator
on FF
Slide Platesothat the clearance
between
the acruator
and the body of the microswitch is approximately
0.3 mm or just comesin contact
as
shownin Fig. I l.
SWITCH
LEVER
I
O.ADJUSTMENTOF PLAY MICROSWITCH
(SW-7
andSW-lI) ACTIVATOR POSITION
As shown in Fig. 12, at stop mode, move the
microswitchactivatorson Play SlidePlatesothat the
clearance
betweenthe activator and the porches of
themicroswitches
isapproximately 1.0mm.
T2

V. HEAD ADJUSTMENT
'@*'o' @,o, ,0,@,r,-
q
Fig.
l3
REV. PLAYBACK
HEAO
P4-2O2
NOTES:
I) As perfect head adjustmenrs
arevitai in attaining
top tape deck perforrnance.
piease
be sure that
theseadjustments
are
properiy
carriedout.
2) Becarefulnot to use
amagnetizedscrew
driver
or
other magnetized
toolsin the vicinity of theheads.
3) Use only new tape as level variation is likely to
occurwhen using
old tape.
4) Demagnetize heads with a Head Demagnetizer
beforeandafterhead
adjusrment.
COMB(REC./ERASE) FWD.PLAYBACK
HEADRE4-6 HEAD P4-2O2
13

A.ljustment
Item
Combination Head
Height Adjustment
Test
Taoe
Suppiv
Signal
optionai
Adjustment
Point
(AX
B)(C)
Remarks
Upper edgeof ch. I head core and the
upper edge of the tape are the same
height.
[rWD
Plavback
Head
Heieht
.{,diustment optionai (DXEXF) Upperedgeof ch. t headcore
andthe
upperedge
of the tape
arethe same
height.
REVPlavback
Head
Height
Adjusrment optlonal REV (GXHXI) Lower edge of ch. i head core and the
lower edge of the tape are the same
heieht.
IrWDPlavback
Head
Azimuth
Alignment
Adiustment
8.000
Hz.
3-3l4
ips
test taDe (F) |
I
I
I
Maximumoutput.
both
channels.
FWDPlavback
Head
GapAlignment
Adiustment
8,000
Hz.
3-3/4
ips
test
tape
Adjust head
gap
surface
sothat thereis
nochange
in outputlevel
when
tension
isappliedto the
suopiy
reel
side.
REV Plrvback
Head
Azrmuth
Alignment
.\djustment
8,000
Hz.
3-3/4
ips
test
taDe Ilaximum output.both
channels
REV Plavback
Head
GapAlignment
Adjustment I
8,000
Hz,
3-314
ips
test
tape REV (K) Adjust head
gap
surtace
sothat thereis
nochange
in output
level
when
tension
is appliedto the supplyreei
side.
Combination
Head
Azrmuth
Alignment
Adjustment
Combination
Head
Gap
Alignment
Adjustment
Scotch
;211
tape
15,000
Hz
-20
dBm
Scotch
=21I
tape
15,000
Hz
-20 dBm (L)
Maximum
output.
both
channeis.
Adjust head
gap
surface
sothat there
is
no changein output levelwhen tension
isappliedto the supply
reel
side.
NOTE: Set
tape
speed
to 7-l/2 ips.
when
making
ali alignment
adjustments.
L4

VI. AMPLIFIER SYSTEM ADJUSTMENT
1.POWERSUPPLY
VOLTAGE
ADJUSTMENT 2.
TAPESPEED
ADJUST}IENT
J
ffi
t
,-l
-|,l,*¡i
=-lI F
ILr-
r'¡r!! |
1:) O'
G"'/-
|||||||ry.I-I:l I _
ffiffR
ilt
IGT
_i
|
gcm /3cc.
VRI IOKE
.at lK8
,:CJUST TO 24V
Fig.14
TestTape
1.000Hz.7-Il2ips
testtape
i9 cm/s!c I
l''- 95cm'/s¿c:
Fis.l5
I
i Rema¡ks
I
3e
Result
24.0V Terminal @, Po*"t
Supply P.C.Boa¡d
Tape
Speed7-ll2 ips.
Mode
STOP
FWD
P.B.\
AdjustmentItem
Power
Supply
VoltaseAdiustment
7-ll2 ips.
Tape
Speed
Adjustment
@t." ',r..fi
3-3/4
ips.
TapeSpeed
Adjustment
i,000Hz.7-ll2
ips.
test
tape FWD
I p.¡.
I
VR2 30
kB 500
Hz xlj% Tape
Speed3-3/4
ips.
r5

3.RECORDING.
PLAYBACKAMPLIFIERADJUSTMENT
VR2D
20K8
^
w
,R
I vR3 '/R3b VRrb
SOKB 2KE 2K8 3CKB
a ^ ,a,a
v¿) V) "lU <-/
A
.9 .V
_t¡ _^(h
3OP iOP
*/LI
23mH
Adjustment tvv ftz, t-Ll¿ tps.
"O" VIJ test tape i vR32kB
i
Adjustment Item TestTape
Supply Signal Mode Adjustment
Point Result Rema¡ks
Playback
Level
Adjustment 700
Hz,7-Il2 ips.
test
tape FWD
P.B. VRl 50
KB 0rl.0 dB
(0.77sv) within 0 t1.5 dB at
rsverse
playback
VU Meter
Sensitivity I 700Hz.7-l12 i FWD
RecordingLevel
Adiustment
Frequency Response
Adjustment
Scotch
#21
I tape.
1,000
Hz
"O" \rU
recording
Scotch
#21
I tape,
1,000
Hz,10,000Hz
-20 dBm
recordins
vR2 20
kB
c25 80P
I tt23mH
0
tl.5 dB
(0.77sv)
1,000Hz to
10.000Hz flat
Lessthan
-30
w
REC Monitor Switch at
SOURCE
Readjust recordinglevel
following bias
adjustment
With Monitor Switch at TAPE
and
SOURCE
Positions.
Bias
Leak
Adiustrnent REC
NOTES:
l. Tape
Speed
at7-Il2ips.
(19
cm/sec.)
2. Tape
SelectoratLOW
NOISE.
3. Output
volume
maximum.
4. Nerv
test
tape
shouldbeused.
5. The
letterb following
an
adjústment
p¿uts
number
indicates
"right channel".
r6

VII. D.C. RESISTANCE OF VARIOUS COILS
Part Desisnation D.C.
Resistance
\fain Motor SCM2.]4KJ Between
BLU-RED100
ohm
Between
YLW-GRN 180ohm
Pick-upCoil
635 ohm
Reel
Motor ]4XO-MR Between
BLU-RED
74otun
BetweenYLW-GRN
166
ohm
PlavSolenoid 1660
THT3 685
ohm
Shut-Off Solenoid 0730
THTl 15
ohm
tlj%
Relay MY44-US-ADADC24V 650
ohm
Relay MTS.2 980
ohm
Head
phone
Output Transformer N16-53sS Primary565
ohm
!15%
Secondarv
0.95
ohm
xIS%
OscillatorCoil
PlavbackHead
oT-204
P4-202
Be¡reenl-3 0.3ohm
Between4-
6 0.7ohm
Between7-9 %+<ffi
168
ohm
Combination
Rec.;EraseHead RE4ó Rec.5.5ohm
Erase
1.8
ohm
NOTE: Resistance
values
shown in this chart areaverase
values.
VIII. CLASSIFICATION OF VARIOUS P.C. BOARDS
I. P.C.BOARD TNTERCHANGEABILITY
CHART
P.C.Board GX-230D GX-230
Relay
P.C.Board MY{008 MY{008
Servo
Control P.C.Board MY-2036 MY-2036
PowerSuppiy
P.C.
Board MY-2037 MY-2037
REC.SW.
P.C.Board MY-204 MY-2044
Transistor
P.C.Board MY-2054 MY-2054
Equalizer
P.C.Board MY.5O
I4
A.B MY.sOI4A.B
Lamp P.C.
Board MY-501s MY-501s
OSC.and Recording
Amp. P.C.Board MY-5016 MY-50r6
Playback
Amp.P.C.Board MY-5017* MY-s017*
Main Amp. P.C.Board MS-5024
NOTE: Asterisk mark indicates"not interchanseable"
t7

2.COMPOSITEVIEWS
OF COMPONENTS
1.
OSC.and
Recording
Amp.
P.C.Board
O4y-5016)
-
i
:
a
:
*-;*;;ri- | ?. i?
.:-::=:=tb1 -l¡b+J
ir Fl .Fi.,*r
i É+
r, i- ul
¿,+]
€¡r"E"F*rT Íl á;,BJ
F'F'
;¡ *1," {,:*J
.&I A
!- I ¿ -1
;. ó ú
;,,¡
¡ril.¿'t J ¡ -¡'¿ ¿. . i,] I ¡*qf
t llfl¿', lff11 9k'-"
d¡-.
,: ' *,".*q \ 3,
ü;;;i9;;¡i;i'.s S.*r,t;a.,
b s;Ss{Elj $.tElE"n"!ñEK;'ie ;i ffi¡gKñl
ry,$::
;i
ffi#;r3*.
*ffi
p
E-qti éuÉl¡l .*l.t¡Fxql
? -a a I O a a ar-ra a -.¡
' ¡ r- t ? t''f ? I'
' lt f ' "-*'I'"'l Qff
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