Pioneer SX-303 User manual

:-_
t
I
I
(DrrloNEEFl'
ORDER
NO.
ARP-
232-0
AM/FM STEREO
RECETVER
sixr3Gl3
o Thisservicemanual
isapplicable
to the KU types.
Forservicing
of the othertypes,
please
refer
to the
additional
service
manual.
o Ge
manuel
d'instruction
serefdre
aumode
der6glage,
enfrangais.
o Este
manual
de
servicio
tratadelm6todo
de
ajuste
escrito
enespafiol.
CONTENTS
1.
2.
3.
4.
5,
6.
7.
SPECIFICATIONS
FRONT
PANEL
FACILITIES
PARTS
LOCATION
BLOCK
DIAGRAM
CIRCUIT
DESCRIPTIONS
.
PACKING
EXPLODED
VIEW
ANDPARTS
LIST
2
3
4
5
6
8
9
8. P.C.
BOARDS
CONNECTION
DIAGRAM 12
9. SCHEMATICDIAGRAM 15
10. ELECTRICAL PARTS
LIST
. . 17
11. DIALCORDSTRINGING ...... 19
12. ADJUSTMENTS... 20
nEcucr 22
AJUSTE ... 24
PICINEEFI ELECTFICINIC CclFlPClFIATIClN 4-1, Meguno 1-chome, Mesuno-ku, Tokyo 1F3, Japan
FIC|NEEFI ELECTFICINI€9 IUAAI lNC. 1925 E. Dorninguez St., Long Beech, Catifonnia gOB1O U.S.A.
FfoNEEFI ELEcrFloNlc [EuFtoPEI N.v. Keerbengtean 1,e74o Bevenen, Betgium
PI('NEEFf ELECTFICINIGB AUaTFIALIA FTY. t-lO. lzA-le4 Boundany Ftoad, Bnaeside, Victonier 819F, .Ausrnatia
MODEL
SX-303
(SX-303L)
COMES
IN FIVEVERSIONS
DISTINGUISHED
AS FOLLOWS:
Model Voltage Remarks
sx-303/KU AC120Vonly U.S.A.model
sx-303/Kc AC120Vonly Canada model
sx-303/s AC110V, 'l2OV
,22OV and
24OV (switchabte) Generalexport model
SX-303L/HE AC220V only European
continentmodel with AM-LW bandtuner
sx-303L/HEZ AC220V only Westgermany model with AM-LW band tuner
YX O DEC.
1982 Printed in
lapan
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Q Q
TEL [phone] QQ 376315150 892498299 TEL [phone] QQ 376315150 892498299
http://www.xiaoyu163.com
http://www.xiaoyu163.com

1.
SPECIFICATIONS
Amplifier Section
Continuous
Average
Power
Output
is
45
watts*
per
channel,
min.,
at
8
ohms
f
rom
40Hertz
to 20,000
Hertzwith
no
more
than
0.3o/ototal
harmonic
distortion.
TotalHarmonic
Distortion(40
Hertz
to 20,fi)0 Hertz,
I ohms,fromTAPE)
continuousrated
povrrcr
output Nomorethan
0.3%
22.5watts
per
channel
power
output
. . . . Nomorethan
O.15yo
Iwatt per channel
power
output
l*"r..irr"ii""oiri.r,i""it,i""r,rlrt,ill'iJir1"=t;?1,
8 ohms,
fromAUX)
continuousrated
power
output Nomore
than
0.3%
DampingFactor
(1kHz,
8 ohms) 22
I
nput (Sensitivity/l
mpedance)
PHONO .....2.smV/S0kilohms
TAPE
PLAY . . . 150
mV/50
kilohms
Phono
Overload
Level
(T.H.D.0.1%.
1,000H2)
PHONO . . 150mV
Output Level
TAPE REC . 150mV
SPEAKER A, B,A series B,off
Frequency
Response
PHONO
(RIAA
Equalization)
. 30Hz to 20,000H2t0.5d8
TAPE PLAY 15Hzto SO,OOOHz+]OA
Tone
Control
BASS
. i9dB (100H2)
TREBLE 19dB
(10kHz)
Loudness
Contour
(Volum
control
setat-40d8position)
. . +8dB
(100H2),
+6dB
(10,000H2)
Humand
Noise
(lHF,
shortcircuited,A network)
PHONO
MM .. 71dB
TAPEPLAY ......97d8
FM Tuner
Section**
UsableSensitivity.. .10.7d8f(O.9pV)
50dBOuieting
Sensitivity
MONO ...15.3dBf
(1.6pV)
STEREO ..37.6d8f (211ty1
Signal-to-Noise
Ratio
MONO ...75d8(at85dBf)
STEREO . . 70dB
(at
85dBf)
Distortion
(at65dBf)
MONO lkHz. ...0.3Yo
STEREOlkHz. ...O.6Yo
CaptureRatio. ..2.5d8
Alternate
ChannelSelectivity
(400kHzl . . 50dB
Stereo
Separation
(lkHz) . .35dB
FrequencyResponse .. 30HztolSkHz,1ffOt
SpuriousResponseRatio. ......7ft8
lmageResponseRatio ....45d8
lF ResponseRatio. ....100d8
AMSuppressionRatio ...45d8
SubcarrierProductRatio. ......31d8
MutingThreshold 27dBf
(6.3pV)
AntennaInput
. . . 300ohms
balanced,75ohms
unbalanced
AM Tuner
Section
Sensitivity
fHF, Loopantenna 32O1N
lm
lHF,Ext. antenna 30gV
Selectivity .2ft8
Signal-to-NoiseRatio . . . ..43d8
lmageResponse
Ratio ....40d8
lF ResponseRatio. .....45d8
Antenna AM LoopAntenna
Miscellaneous
Power
Requirements . AC120V, 60Hz
Power
Consumption. . . 190Watts(UL),
22SVA(CSA)
Dimensions . . . 42O
(W)
x 98 lHl x 214
(D)
mm
16-9/16(W)X 3-718(H)
X 8-7116(D)
in
Weight
(without
package) . .5kS (11
tO)
FurnishedParts
FMT-typeAntenna ......1
AMI-oopAntenna ........1
Operating
Instructions 1
'Measured pursuant to the Federal Trade Commission's Trade
Regulation rule on PovverOutput Claims for Amplifier.
**FM muting functions with this unit when the signals are weak.
The unit's internal wires are therefore treated so that the signals
are not muted when the sensitivity is measured.
NOTE:
Specifications and design subject to possible modification without
notice.
2
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Q Q
TEL [phone] QQ 376315150 892498299 TEL [phone] QQ 376315150 892498299
http://www.xiaoyu163.com
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2.
FRONT
PANELFACILITIES
O powen
swrrcH
Push
this to wrritch on andoff the unit's power.
Power
is
suppliedat the depressed
(r) switch
position
(ON)
and
turned
off atthereleased
(I) position (OFF).
@ HenopHoNE
JAcK
Connectthe plug on the stereoheadphones
to this jack
whenlisteningto soundthrough headphones.
@rorue
coNTRoLs
BASS :Thebass isincreased
whenthiscontrol
isrotated
clockwisefrom the center
position
andreduced
whenrotated
counterclockwise.
TREBLE :
The treble is increased
when this control is
rotatedclockwise from the center
position
and
reduced
whenrotated
counterclockwise.
@ eeLeNcE
coNTRoL
This is normally
kept at its center
position.
lt is rotated
when
the volume
of sounddeliveredthroughthe left and
right
channelsof thespeakersor headphones
differs.
The right channelvolumeis reduced
whenthe control is
rotatd toward the LEFT from the center position while
the left channel volume is reducedwhen it is rotated
toward
theRIGHT.
@rurucrroN
swrrcHEs
PHONO :Presswhenlistening
to records.
FM :Press
whenlisteningto FM broadcasts.
AM :Presswhenlistening
to AM broadcasts.
@rape (ADPT)
swrrcH
This is depressed
when usinga tape deckor adaptor unit
connected
to therear
panel
TAPE/ADAPTOR
jacks.
o LouorrrEss
swtTcH
Depress
this svrritchto the ON position when listeningto
soundat a low level
of volume.This
will enhancethe bass
and treble and givemore life to the soundevenat a low
volume.
@ voluruE
coNTRoL
Use this to adjustthe volume of the sounddelivered
through
the speakersor headphones.
The volume is increased
when this control is rotated
clockwisefrom
theminimum
"0" position.
@ ruruIruG
tNDIcAToR
(TUNING)
Thislightsup to indicate
that an FM,AM stationhas
been
tunedin.
@ sreneorNDrcAToR
(srEREo)
This lightsup automaticallywhen an FM stationbroad-
castingin stereo hasbeen
tunedin.
@speerERs
swrrcHEs
Theseare usedto select the speakersthrough which you
will listen
to thesound.
Theselected
speakersarenowworking.
A: The sound is heard from the speakersconnectedto
the
speaker
A terminalsontherear
panel.
B: The sound is heard from the speakersconnectedto
the
speakerBterminals
ontherear
panel.
No sound
will be
heard
when
SPEAKERS
A andBswitches
are both released.
This isthe positionat whichthe sound
can
beheard
through
theheadphones.
NOTE:
No rcund will be heard through the spakers when both the A
and B switches are depressed if only one set of speakershas
been
connected to either the A or I SPEAKE RS terminals.
@ FREoUENcY
scALE
This indicates
the frequencyof the broadcasting
station
(FM,
AM).
The
top levelfigures
(88
- 108)
indicate
theFMband.
The bottom level figures
(55- 160)indicate
theAM band.
@ TUNTNG
KNoB
Rotatethisknob
to pick
up
stations
(FM,
AM).
@ POWER
|ND|CATOR
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TEL [phone] QQ 376315150 892498299 TEL [phone] QQ 376315150 892498299
http://www.xiaoyu163.com
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3.PARTS LOCATION
FrontPanel
View
Speakerknob
AAD60A
Front panel
assembly
NOTES:
. Parts without part nu ber connot be supplied.
. The b morh found on aome component ports indicates the importonce of the
sofety factor of the port- Thereforc, uhen replocing, be 6ure to use
ports of id.enticol
designation.
. For your Potts Stock Control, the fost mot)ing items are indicated u)ith the moths
ta and l.
'' GENERALLY MOWS FASTER THAN '.
Thb claesificotion shall be odjusted by eoch di;tributor becouseit deDends on model
numbe f, temperature, humidity, etc.
Bonnet
ANE4lO
ANM-293
AAD$O5
..-":.n
f\,- KnobA (vo LU1ME)
AAB316
FunctionknobA
{TAPE,
LOUDNESS)
AAD€06
Function knob B
(PHONO,
FM,
AM)
AAD607
Phone
jack
AKN-(X5
Knob B
(BASS,
TREBLE,BALANCE)
AAB3I7
RearPanelView
Earth terminal
Complexterminal
AKX{73
TopView
l\r*t Fuse
(T2.5A)
AEK-123
A** Pushswirch
(POWER'
ASG-541
A ac socket
AKP.O39
AWB{44
** tc
M5153L
Switchassembly
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Q Q
TEL [phone] QQ 376315150 892498299 TEL [phone] QQ 376315150 892498299
http://www.xiaoyu163.com
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4.BLOCK DIAGRAM
FRONT
END (1/3)
T
| 3OOO
. BAL
FM
I
L rrrupar
l- cND
AM
I LOOP
L ANT
FM
MIX AMP
LED DRIVER FM
MUTE
AM FRONT
ENO
[5dtl sr-l
PHONO
FM
(Lch)
FM(Rch)
l- crav
Lch REC
i-
,"o"o
f eiror,ro
Rch REC
l-
".o"
sr-4
TAPE
(t/? )
sr-5
LO
UONESS
(?/2) TONECONTROL
vR2-2,2-3
EQUALIZERAMP
lzsmrl
t'EryI pHoNEs
TO
r_-
134,4/41
Rch
SPEAKE RS
ac
r20v
60
Hr
+92
(
15.4V
s2-2
SP- B
(vzl
s2-l
SP-A
lt/2)
lI"o
],, ^
SI-l : FUt{CTION
(PHOtlO)
SI-2: FUNCTION
{FM)
sr-5 : FUt{cTroN
( AM)
SI-4 : TAPEMONITOR
sr-5:LouoNEss
9!L- oFF
oN -.9!E
oN -.g_Eq
ON
--qEE
or -_q!! S2.I : SPEAKERS S2.2: SPEAXERS
07
I_9_l!-
- oFF
!-!L - oFF
FM.IF AMP
FT.IIF,/OET MPX
RE6ULA.
rfrR
tx
METER
OETECTOR
r-;1-l
rcr i lrJ i
Itfr I
lt/2) | (t/4)
ffi--D"t o='""o'
POWERAMP
sr-4 sr-5
|2/2t (2/2 )
AM IF AMP
+82 AM
04
POWER
ON,/OFF MUTING
POWERSUPPLY A PROTECTOR
sror i PoWER oil - oFF
5
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TEL [phone] QQ 376315150 892498299 TEL [phone] QQ 376315150 892498299
http://www.xiaoyu163.com
http://www.xiaoyu163.com

5.
CIRCUITDESCRIPTIONS
FM Front End
A unitized variable capacitor type front end
unit is used consisting of an FET RF single stage
amp, local oscillator/mixer IC and an IF trans-
former.
FM lF Amp, DetectorandMPX Circuit
A 2-transistor IF amp with ceramic filter is used
and the next stage
hasan IC (M51533L) contain-
ing the FM IF detdctor andMPX circuit. The block
diagram
of IC M51533L is shownin Fig. 5-1. This
IC uses a peak detection method which can be
adjusted with a single coil. The PLL method is
employed to reconstitute the 38kHz sub-carrier
for the MPX circuit.
The IF signalis input at pin 1 andthe detection
output is obtained from pin 5. The detection out-
put passes
through the muting Q4, goes
to pin 9,
passes through the MPX circuit and the stereo
signals are obtained frorn pins 11 and 1'2. In
addition, this unit detectsthe presence
or absence
IL OUT ROUT
of a pilot signal to automatically switch between
stereo and mono reception by R14 which is con-
nected to pin 14. When a stereosignalis received,
pin 13 drops to the low level to light the stereo
indicator. When pin 2 is grounded, the PLL VCO
and FM IF operation stop (for AM).
FM Mutingand LED Driver
With this unit, muting is automatically activated
when the antenna input drops below 10pV. As the
antenna input decreases, the voltage at pin 3
drops, Q5 is turned off and Q6 is turned on. As a
result, the gate voltage of Q4 drops, Q4 is turned
off and the detector output circuit is blocked
(Fig. 5-1). When an FM or AM station is tuned
in, the base
potential of Q5 is raised,Q5 isturned
on and the tuning indicator lights.
nrtr F?? |
OETECTOR
INPUT
BUFFER
LEVEL
METER
CIRCUIT
S
TER
EO
5W
rTC
H
Fig.5-1 FMlF,Detectorand
MPX
circuit
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Q Q
TEL [phone] QQ 376315150 892498299 TEL [phone] QQ 376315150 892498299
http://www.xiaoyu163.com
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AM Tuner
This uses a variable capacitor type tuning
circuit composed of three transistors, a 2-fuan-
sistor front end and a single transistor AM IF
detector.
AF Section
The equalizer circuit has a low-noise operation
amp(2 channel)M5218P.
The power amp hasa 45 watt output power IC
STK4141-2S
(See
Fig.5-4).
The tone control circuit is placed in the negative
feedback
loop of the power amp.
Protective
Circuits
This unit has a circuit to detect DC voltages
at
the power amp outputs and a muting circuit that
operateswhen power is turned on and off.
Fig. 5-2 shows the construction of the DC
voltage protection circuit. When a DC voltage
appears at the power amp output, either Q13
(plus) or Q14 (minus) is activated depending on
the polarity of the DC voltage and a trigger is
applied to D15. This turns on D15, +81 isshorted,
the fuse on the primary side is cut and the power
supply circuit is shut off.
Fig. 5-3 showsthe power on/off muting circuit.
Time constant t1 is longer than t2 so that imme-
diately after the power is turned on, the emitter
potential of Q15 exceeds
its base
potential, Q15 is
turned on to activate Q16 and Q17 and ground the
signal. A few seconds later, the base potential of
Q15 rises
to turn off Q15 alongwith Q16 and e1Z.
When the power is turned off, the charge of
C161 passes
through D18; it is almost completely
discharged in an instant to make the base
potential
of Q15 zero. However,because
the charge
of C160
remains, Q15 is turned on and muting is activated
in the same manner as when power is turned on.
TO
SPEAKE
R
SWITCHES
Fig.
5-2 DC
Voltage
protection
circuit
TOPOWERAMP tr,r2
POWERAMP
( Lch)
Fig.5-3 Power
ON/OFF
muting
circuit
const
ont
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TEL [phone] QQ 376315150 892498299 TEL [phone] QQ 376315150 892498299
http://www.xiaoyu163.com
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I
rNr(+)l
2
rN
l(-
)
6.
PACKING
ta
OUT2
Equivalent
circuit
of power
lC
r8
tN2(+)
t7
rN2(-)
GND 68
MUTING
Fis.5-4
9
VEE
fiI
I
.J
t6
GN
to
OUT
I
Mark No. Part No. Doscription
1.
2.
3.
4.
5.
AHA.335
AR8526
ATB{76
ADH.OOS
AHE-107
Sidepad
Operating instructions
(English
)
Loop antenna assembly
T-type antenna
Packingcase
a
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TEL [phone] QQ 376315150 892498299 TEL [phone] QQ 376315150 892498299
http://www.xiaoyu163.com
http://www.xiaoyu163.com

T.EXPLODEDVIEW
AND PARTS LIST
NO?ES:
o Partswithout part number cannot be
supplied.
o The S marh found on some component parts indicates the importance of the
safety factor of thepart. Therefore, when replacing, be sureto use partsof identicol
designotion.
o For your Parts Stoch Control, the fast mouing items are indicated with the morhs
t* ond *.
*T GENERALLY MOWS TASTER THAN ).
This classification shallbeadjusted by eachdistributor becauseit depends on model
number, temperaturc, humidity, e
tc.
lVlark No. Part No. Decriptions
Mark No. Part No. Description
1. ANE410 Bonnet
2. BBZ30P080FZK Screw
(3
x 8)
A * 3. ATT-944 Power
transformer
{120V}
4. PMZ30PO60FMC Screw
(3x 6l
5, AAD€O8 Speaker
knob
6. VMZ30P06OFMC Screw(3x6)
7. NK9OFUC Nut
8. AAB-317 Knob B
{BASS,
TREBLE,
BALANCE}
9. NKT0FUC Nut
10. AAAO84 Tuningknob
11. A48-316 KnobA (VOLUME)
12. ANM-293 Frontpanel
assembly
13. AAD€07 Function knobB (PHONO,
FM,
AM)
14. AAD€06 Function knobA (TAPE.
LOUDNESS}
A ** ts. ASG-541 Pushswitch
(POWER)
16. AAD€05 Powerknob
17. AEC-784 Cabinet bumper
18. AXA-373 Tuning
shaft
19. AEC471 Nylonrivet
20. MTZ3OPIOOFZK Screw
(3x 1O)
a ** z't. AEK-123 Fuse
(T2.5A)
A 22. AKP-039 ACsocket
A 23. ADG-073 Ac power
cord
24. GWM-265 Complexassembly
25, AKN-045 Phone Jack
(PHONES)
** 26. SUJSLYXSF Speaker
switch
A 27. ACGO17 Ceramic
(0.01
)
24. BBT30P080FZK Screw
(3x 8)
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
Speakerswitch assembly
Switch holder
Pullyassembly
LED assembly
Earth
Mountingplate
Pully assembly
Pully assembly
Pully holder
Headphone
jack
assembly
Chassis
Bottom Plate
Binder
Earth terminal
Rearpanel
Tuningdrum
Smoother
Pointer holder
Pointer assembly
Heat
sink
Wire holder
65.
66.
67.
68.
69.
I
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Q Q
TEL [phone] QQ 376315150 892498299 TEL [phone] QQ 376315150 892498299
http://www.xiaoyu163.com
http://www.xiaoyu163.com

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3
7
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0 9 9
2
8 9
4 2
9 8
T E L 1 3 9 4 2 2 9 6 5 1 3 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3
Q Q
TEL [phone] QQ 376315150 892498299 TEL [phone] QQ 376315150 892498299
http://www.xiaoyu163.com
http://www.xiaoyu163.com