Features
Maximum power output of 170 watts per channel (at 4 ). This unit can be used as a bridging amplifier with a maximum output of 400 watts. Direct connection can be made with the speaker output of your car audio if it is not equipped with a line output (High level input connection). Built-in variable LPF (Low-pass filter), HPF (Highpass filter) and low boost circuit. Protection circuit and indicator provided. TEST-TONE functions of easy-checking for the System performance. Pulse power supply* for stable, regulated output power.
* Pulse power supply This unit has a built-in power regulator which converts the power supplied by the DC 12 V car battery into high speed pulses using a semiconductor switch. These pulses are stepped up by the built-in pulse transformer and separated into both positive and negative power supplies before being converted into direct current again. This is to regulate fluctuating voltage from the car battery. This light weight power supply system provides a highly efficient power supply with a low impedance output.

Caractristiques

Puissance de sortie maximale de 170 watts par canal ( 4 ). Cet appareil peut tre utilis comme amplificateur de pontage dune sortie maximale de 400 watts. Une connexion directe est possible avec la sortie haut-parleur de votre autoradio si celle-ci nest pas quipe dune sortie de ligne (connexion dentre haut niveau). Filtre passe-bas (LPF), filtre passe-haut (HPF) variables et circuit damplification des graves intgrs. Avec circuit et indicateur de protection. Fonctions TEST-TONE de vrification des performances du systme. Alimentation lectrique par impulsions* pour une puissance de sortie stable, rgule.
* Alimentation lectrique par impulsions Cet appareil est quip dun rgulateur de puissance intgr qui convertit la puissance fournie par une batterie de voiture de 12 V CC en impulsions ultra-rapides au moyen dun commutateur semi-conducteur. Ces impulsions sont amplifies par le transformateur dimpulsions intgr et spares en alimentation positive et ngative avant dtre reconverties en courant continu. Ce processus permet de compenser les fluctuations de tension provenant de la batterie de la voiture. Ce systme dalimentation de faible poids assure une alimentation lectrique trs efficace pour une sortie dimpdance faible.
Location and Function of Controls
1 POWER indicator Lights up in green during operation. 2 PROTECTOR indicator OVER CURRENT: Lights up in red when receiving a powerful signal. OFFSET: Lights up in red when the voltage going out to the Speaker terminal or the Pin Jack is too high. THERMAL: Lights up in red when the temperature rises to an unsafe level. 3 TEST-TONE button When the button is pressed, operations of a built-in Oscillator allow the System conditions to check. 4 FILTER selector switch When the switch is in the LPF position, the filter is set to low-pass. When in the HPF position, the filter is set to high-pass. 5 Cut-off frequency adjustment control Sets the cut-off frequency (50300 Hz) for the low-pass or high-pass filters. 6 LOW BOOST level control Turn this control to boost the frequencies around 40 Hz to a maximum of 10 dB. 7 LEVEL adjustment control The input level can be adjusted with this control when using source equipment made by other manufacturers. Turn it to MAX when the output level of the car audio seems low.
Emplacement et fonction des commandes

1 Indicateur POWER Sallume en vert en cours fonctionnement. 2 Indicateur PROTECTOR OVER CURRENT: Sallume en vert lors de la rception dun signal puissant. OFFSET: Sallume en rouge lorsque la tension de sortie vers le terminal du hautparleur ou la prise broches est trop leve. THERMAL: Sallume en rouge lorsque la temprature atteint un niveau trop dangereux. 3 Touche TEST-TONE Lorsque vous appuyez sur cette touche, la mise en marche dun oscillateur intgr permet de vrifier le systme. 4 Commutateur de slection FILTER Lorsque le commutateur de slection est en position LPF, le filtre est rgl sur passe-bas. Lorsquil est en position HPF, le filtre est rgl sur passe-haut.

TEST TONE

LPF OFF HPF 50Hz 300Hz

POWER/PROTECTER

POWER OVER CURRENT OFFSET THERMAL

FILTER

5 Commandes de rglage de la frquence de coupure Rgle la frquence de coupure (50300 Hz) des filtres passe-bas ou passe-haut. 6 Commande de niveau LOW BOOST Tournez cette commande pour amplifier les frquences autour de 40 Hz jusqu un maximum de 10 dB.

+10dB MIN

LOW BOOST LEVEL (40Hz)
7 Commande de rglage LEVEL Le niveau dentre peut se rgler avec cette commande lors de lutilisation dquipements source dautres fabricants. Mettez-le sur MAX lorsque le niveau de sortie de linstallation audio parat faible.

LOW BOOST

Cut-off frequency/Frquence de coupure

-10 -20

50Hz HIGH PASS LOW PASS 300Hz 150Hz 150Hz 50Hz 300Hz

-30 -40

-50 -60 -70

-100 1k

FREQUENCY
Circuit Diagram / Schme du circuit

Front : Avant :

Normal
HPF OFF LPF LOW BOOST Power AMP

(BTL.)

Inverted

HPF Power AMP

OFF LPF LOW BOOST
Rear : same as Front Arrire : identique lavant

Installation

Before Installation
Mount the unit either inside the trunk or under a seat. Choose the mounting location carefully so the unit will not interfere with the normal movements of the driver and it will not be exposed to direct sunlight or hot air from the heater. Do not install the unit under the floor carpet, where the heat dissipation from the unit will be considerably impaired. First, place the unit where you plan to install it, and mark the positions of the four screw holes on the surface of the mounting board (not supplied). Then drill the holes approximately 3 millimeters (mm) in diameter and mount the unit onto the board with the supplied mounting screws. The supplied mounting screws are 15 mm long. Therefore, make sure that the mounting board is thicker than 15 mm.

The POWER indicator does not light up.

Cause/Solution

The fuse is blown. t Replace the fuse with a new one. The ground lead is not securely connected. t Fasten the ground lead securely to a metal point of the car. The voltage going into the remote terminal is too low. The connected master unit is not turned on. t Turn on the master unit. The system employs too many amplifiers. t Use a relay. Check the battery voltage (10.V).

Owners Record

The model and serial numbers are located on the bottom of the unit. Record the serial number in the space provided below. Refer to these numbers whenever you call upon your Sony dealer regarding this product. Model No. XM-754SX Serial No.
The OVER CURRENT indicator light up Turn off the power switch. The speaker outputs are short-circuited. t Rectify in red. the cause of the short-circuit. The OFFSET indicator lights up in red. Turn off the power switch. Make sure the speaker cord and ground lead are securely connected. The THERMAL indicator lights up in red. The unit heats up abnormally. Use speakers with suitable impedance. (stereo) , (when used as a bridging amplifier). Make sure to place the unit in a well ventilated location. The power connecting leads are installed too close to the RCA pin cords. t Keep the leads away from the cords. The ground lead is not securely connected. t Fasten the ground lead securely to a metal point of the car. Negative speaker leads are touching the car chassis. t Keep the leads away from the car chassis. The sound is muffled. The sound is too low. The FILTER switch is set to the LPF position. The level adjustment control is set to the MIN position.
Alternator noise is heard.

XM-754SX

Sony Corporation 2001

Printed in Korea

Specifications Guide de dpannage
La liste suivante vous aidera rsoudre la plupart des problmes que vous pouvez rencontrer avec cet appareil. Avant de passer la liste en revue, vrifiez les connexions et les procdures de fonctionnement. Problme
Lindicateur POWER ne sallume pas.
Le fusible est grill. t Remplacez le fusible par un neuf. Le fil de masse nest pas connect correctement. t Fixez correctement le fil de masse un point mtallique de la voiture. La tension entrant la borne de tlcommande est trop faible. Lappareil matre connect nest pas allum. t Mettez lappareil matre sous tension. Le systme utilise trop damplificateurs. t Utilisez un relais. Vrifiez la tension de la batterie (10,V).
AUDIO POWER SPECIFICATIONS POWER OUTPUT AND TOTAL HARMONIC DISTORTION 75 watts per channel minimum continuous average power into 4 ohms, both channels driven from 20 Hz to 20 kHz with no more than 0.04% total harmonic distortion per Car Audio Ad Hoc Committee standards.

Other Specifications

OTL (output transformerless) circuit Pulse power supply Inputs RCA pin jacks High level input connector Outputs Speaker terminals Speaker impedance (stereo) (when used as a bridging amplifier) Maximum outputs Four speakers: 170 W 4 (at 4 ) Three speakers: 170 W 2 + 400 W 1 (at 4 ) Two speakers: 400 W 2 (at 4 ) Rated outputs (supply voltage at 14.4 V) Four speakers: 75 W 4 (20 Hz 20 kHz, 0.04 % THD, at 4 ) 100 W 4 (20 Hz 20 kHz, 0.1 % THD, at 2 ) Two speakers: 200 W 2 (20 Hz 20 kHz, 0.1 % THD, at 4 ) Frequency response 5 Hz 50 kHz ( dB) Circuit system Harmonic distortion 0.005 % or less (at 1kHz, 4 ) Input level adjustment range 0.2 6.0 V (RCA pin jacks) 0.V (High level input) High-pass filter Hz, 12 dB/oct Low-pass filter Hz, 12 dB/oct Low boost dB (40 Hz) Power requirements 12 V DC car battery (negative ground) Power supply voltage 10.V Current drain at rated output: 40 A (4) Remote input: 1.5 mA Dimensions Approx. 264 mm (w/h/d) (10 1/14 1/8 in.) not incl. projecting parts and controls Mass Approx. 3.5 kg (7 lb. 11 oz.) not incl. accessories Supplied accessories Mounting screws (4) Design and specifications are subject to change without notice.
Lindicateur OVER CURENT sallume en rouge. Lindicateur OFFSET sallume en rouge. Lindicateur THERMAL sallume en rouge.
Coupez linterrupteur dalimentation. Les sorties de haut-parleur sont courtcircuites. t Remdiez la cause du court-circuit. Coupez linterrupteur dalimentation. Assurez-vous que le cordon de hautparleur et le fil de masse sont correctement branchs. Lappareil chauffe anormalement. Utilisez des haut-parleurs dune impdance approprie. (stro) , (utilis comme amplificateur en pont). Installez lappareil dans un endroit bien ar. Les cbles dalimentation sont installs trop prs des cbles broches RCA. t Eloignez les cbles lun de lautre. Le fil de masse nest pas connect correctement. t Fixez correctement le fil de masse un point mtallique de la voiture. Les fils ngatifs des haut-parleurs touchent la carrosserie de la voiture. t Eloignez les fils de la carrosserie de la voiture.
Lalternateur met un bruit.
Le son est touff. Le son est trop faible.
Le commutateur FILTER est mis en position LPF. La commande de rglage de niveau est mise en position MIN.

Connections

Precautions
This unit is designed for negative ground 12 V DC operation only. Use speakers with suitable impedance. 2 to 8 (stereo). Do not connect any active speakers (with built-in amplifiers) to the speaker terminals of the unit. Doing so may damage the active speakers. Avoid installing the unit where: it would be subject to high temperatures such as from direct sunlight or hot air from the heater it would be exposed to rain or moisture it would be subject to dust or dirt. If your car is parked in direct sunlight and there is a considerable rise in temperature inside the car, allow the unit to cool down before use. When installing the unit horizontally, be sure not to cover the fins with the floor carpet etc. If this unit is placed too close to the car radio, interference may occur. In this case, relocate the amplifier away from the car radio. If no power is being supplied to the master unit, check the connections. This power amplifier employs a protection circuit* to protect the transistors and speakers if the amplifier malfunctions. Do not attempt to test the protection circuits by covering the heat sink or connecting improper loads. Do not use the unit on a weak battery as its optimum performance depends on a good power supply. For safety reasons, keep your car audio volume moderate so that you can still hear sounds outside your car.

If you have any questions or problems concerning your unit that are not covered in this manual, please consult your nearest Sony dealer.
* Circuit de protection Cet amplificateur est quip dun circuit de protection qui entre en service dans les cas suivants: Surchauffe de lappareil Production dun courant continu Court-circuit aux bornes des haut-parleurs. Lindicateur PROTECTOR sallume en rouge et lappareil sarrte. Si le cas se prsente, coupez lalimentation de lappareil raccord et jecrez la cassette ou le disque compact avant dexaminer la cause de la dfaillance. Si lamplificateur est trop chaud, attendez quil refroidisse.
Power Connection Leads Cbles dalimentation
Pour toute question ou problme qui ne serait pas trait dans ce manuel, consultez votre concessionaire Sony.
Speaker cord direct in connector Cordon de haut-parleur directement dans le connecteur 1
Left speaker Haut-parleur gauche Right speaker Haut-parleur droit
Black-striped cord Cordon ray noir
Fuse (40 A) Fusible (40 A) +12 V car battery Batterie de voiture +12 V to a metal point of the car vers une partie mtallique de la carrosserie
Remote output* Sortie de tlcommande* (REM OUT) Car audio Autoradio
Front Avant Car audio Autoradio

Rear Arrire

Right speaker Haut-parleur droit Left speaker Haut-parleur gauche

White Blanc

Grey Gris

Green Vert

Purple Mauve
* If you have the factory original or some other car audio without a remote out-put on the amplifier, connect the remote input terminal (REMOTE) to the accessory power supply. * Si vous disposez du modle dorigine ou dun autre autoradio dont lamplificateur ne comporte pas de sortie de tlcommande, raccordez la borne dentre de tlcommande (REMOTE) la prise dalimentation accessoires.
Left speaker Haut-parleur gauche

Car audio Autoradio

Right speaker Haut-parleur droit

Black/White Noir/Blanc

Black/Grey Noir/Gris
Cord diameter 0.3 1.25 mm (AWG 22 16) Section du cordon : 0,3 1,25 mm (AWG 22 16) Flat-head screwdriver Tournevis lame plate 11 (7/16) Unit : mm (in.) Unit : mm (po.)
Notes on the power supply Connect the +12 V power supply lead only after all the other leads have been connected. Be sure to connect the ground lead of the unit securely to a metal point of the car. A loose connection may cause a malfunction of the amplifier. Be sure to connect the remote control lead of the car audio to the remote terminal. When using a car audio without a remote output on the amplifier, connect the remote input terminal (REMOTE) to the accessory power supply. Use the power supply lead with a fuse attached (40 A). Place the fuse in the power supply lead as close as possible to the car battery. Make sure that the leads to be connected to the +12 V and GND terminals of this unit are larger than 10-Gauge (AWG10) or have a sectional area of more than 5 mm2.

Line Input Connection (with Speaker Connection 1, 2 or 4) Connexion dentre de ligne (avec connexion de haut-parleur 1, 2 ou 4)
Line Input Connection (with Speaker Connection 3) Connexion dentre de ligne (avec connexion de haut-parleur 3)

LINE OUT

Front Avant Rear Arrire Note Make sure that the line output from the car audio is connected to the jack marked L (BTL) on the unit.
Remarque Vrifiez que la sortie de ligne de lautoradio est raccorde la prise portant lindication L (BTL) sur lappareil.
Left channel Canal gauche
Right channel Canal droit

Speaker Connections

4-Speaker System (with Input Connection A or C) Systme 4 haut-parleurs (avec connexion dentre A ou C)
For details on the settings of switches and controls, refer to Location and Function of Controls.
Raccordement de haut-parleurs
3-Speaker System (with Input Connection A or C) Systme 3 haut-parleurs (avec connexion dentre A ou C)
Pour plus de dtails sur les rglages des commutateurs et commandes, reportez-vous Emplacement et fonction des commandes.
Left Gauche Left Gauche Front speakers (min. 2) Haut-parleurs avant (min. 2) Right Droit Left Gauche Right Droit Rear speakers (min. 2) Haut-parleurs arrire (min. 2) Notes In this system, the volume of the subwoofer will be controlled by the car audio fader control. In this system, the output signals to the subwoofer are a combination of both the REAR L and R INPUT jacks or the REAR high level input connector signals. Full range speakers (min. 2) Haut-parleurs pleine gamme (min. 2)
Subwoofer (min. 4) Subwoofer (min. 4)

Right Droit

Remarques Dans ce systme, le volume du subwoofer est contrl par le fader de lautoradio. Sur cet appareil, les signaux transmis vers le subwoofer sont constitus des signaux des prises REAR L et R INPUT.
2-Speaker System (with Input Connection B or D) Systme 2 haut-parleurs (avec connexion dentre B ou D)
2-Way System (with Input Connection A or C) Systme 2 voies (avec connexion dentre A ou C)

Left Gauche

BTL BTL BTL BTL
Right Droit Subwoofers (min. 2) Subwoofers (min. 2)
Left speaker (min. 4) Haut-parleur gauche (min. 4)
Right speaker (min. 4) Haut-parleur droit (min. 4)
Full range speakers (min. 2) Haut-parleurs pleine gamme (min. 2)
Note In this system, the volume of the subwoofers will be controlled by the car audio fader control.
Remarque Dans ce systme, le volume des subwoofers est contrl par le fader de lautoradio.

XM-222MK2

SERVICE MANUAL

Ver 1.1 2002. 03

Canadian Model AEP Model UK Model E Model

SPECIFICATIONS

OTL (output transformerless) circuit Pulse power supply Inputs RCA pin jacks High level input connector Input level adjustment range 0.V (RCA pin jacks), 0.V (High level input) Outputs Speaker terminals Speaker impedance (stereo) (when used as a bridging amplifier) Maximum outputs 100 W 2 (at 4 ) 222 W (BTL, at 4 ) Rated outputs (supply voltage at 14.4 V) 35 W 2 (20 Hz 20 kHz, 0.04% THD, at 4 ) 40 W 2 (20 Hz 20 kHz, 0.1% THD, at 2 ) 80 W (Monaural) (20 Hz 20 kHz, 0.1% THD, at 4 ) Frequency response 5 Hz 80 kHz ( +0 dB) 3 Harmonic distortion 0.005% or less (at 1 kHz, 4 , 10 W) Low-pass filter 80 Hz, 18 dB/oct Power requirements 12 V DC car battery (negative ground) Power supply voltage 10.V Current drain at rated output : 12 A (4 , 35 W 2) Remote input : 1.5 mA Dimensions Approx. 158 mm (w/h/d) not incl. projecting parts and controls Mass Approx. 1.6 kg not incl. accessories Supplied accessories Mounting screws (4) High level input cord (1) Protection cap (1) Design and specifications are subject to change without notice. Circuit system

STEREO POWER AMPLIFIER

9-873-557-02

2002C0400-1 2002. 03

Sony Corporation
e Vehicle Company Published by Sony Engineering Corporation
XM-222MK2 SECTION 3 DIAGRAMS

3-1. BLOCK DIAGRAM

-1 -1 L (BTL) 6

PRE AMP IC801 (1/2) 5

LPF IC802 (1/2) 6 S801-1 LPF (80Hz) ON OFF
GAIN CONTROL AMP IC803 (1/2) 7 SWITCH Q101 DIFFERENTIAL AMP Q102 DRIVE AMP Q104 DRIVE AMP Q108 POWER AMP Q110

CN802 SPEAKER OUT

L VR801-1 LEVEL BIAS Q106,107

CNJ801 INPUT

DIFFERENTIAL AMP Q103

DRIVE AMP Q105

DRIVE AMP Q109

POWER AMP Q111

OVERLOAD DET Q112
PRE AMP IC801 (2/2) -2 -2 R 2 3

LPF IC802 (2/2) 1

GAIN CONTROL AMP IC803 (2/2) S801-2 LPF (80Hz) 1 SWITCH Q201 DIFFERENTIAL AMP Q202 DRIVE AMP Q204 DRIVE AMP Q208 POWER AMP Q210

OFFSET DET Q852,853

R VR801-2 LEVEL MUTE Q851 BIAS Q206,207

CNJ802 HI LEVEL

ON L R OFF

DIFFERENTIAL AMP Q203

DRIVE AMP Q205

DRIVE AMP Q209

POWER AMP Q211

OVERLOAD DET Q212

B+ (14.6V)
15V REG Q951,952, D953 DC DET 4 ICPROTECTOR Q802

B(-14.6V)

-15V REG Q953,954, D954 RECT D951,952 DC-DC CONVERTER TRANSFORMER T901

INVERTER Q903

ERROR LED DRIVE Q803 LD801 POWER/ PROTECTOR

B+ SWITCH Q902

F901 20A

CN801 +12V

B+ (26.2V) INVERTER Q904 10
POWER ON/OFF Q901 REM GND

B(-26.2V)

THERMAL Q801

Signal path

DC-DC CONVERTER IC901

: AUDIO

TH801 TH802
3-3. SCHEMATIC DIAGRAM Refer to page 10 for IC Block Diagram and Common Note on Schematic Diagrams.
R118 Q104 Q108 R124 Q107 Q110 R133 Q112 R126 R129 R130 R125 R120 R123 R128
C113 C119 R138 R137 CNJ802 C220 R239 R237 C219 R238 C120 R139 Q103 R119 C114 R122

C115 Q106

C116 R135 R127 Q111

C117 C118 C218 C217

C104 C857 C112 R131 R132 CN802 C107 Q101 R105 IC802 (1/2) C106 S801 C108 C208 C110 C210 C206 R206 R207 IC802 (2/2) R205 C209 IC803 (2/2) C211 Q201 R108 R208 R109 R209 R110 R210 VR801 R111 R211 C109 C111 IC803 (1/2) R112 R113 Q204 C213 R224 Q207 Q210 R213 Q203 Q202 R219 C214 R220 Q205 R212 R227 R215 R217 D202 R221 Q209 Q211 R236 R136 R223 R222 Q206 R225 R228 C215 R226 R229 C216 R230 R235 R214 R216 D201 R218 Q208 R233 Q212

C101 R101 C102 R102 C103

R106 R107 IC801 (1/2) R104

C858 CNJ801

C201 R201

R204 IC801 (2/2)

C203 C202 R202 R203 C207
D903 Q851 R851 R917 R852 R915 R853 IC851 D851 C851 D852 R918 R854 R920 R919 Q904 C908 R916 Q903 C907

T901 D951

R951 R952 L951 C951 C952 C953 C954 R956 R957 D952 C955 C956

R953 D953 D954 R958

C852 C958 R856

R857 Q853

IC B/D
Q902 R961 R914 C801 R905 Q901 CN801 F901 C901 R901 C902 L901 D901 R902 R903 R904 R803 Q801 D902 C904 C802 R814 R913 C909 R909 R912 R911 PL801 C805 R804

R910 C906

R859 C804 TH801 TH802

R809 R810

R812 R811
R862 R907 R802 D803 IC901 D802

R813 R806 R807 C803 Q803

R805 R808

Waveform

1V/DIV, 5sec/DIV 3.4Vp-p 15sec

Ver 1.1

SECTION 4 EXPLODED VIEW
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS. (In addition to this, the necessary note is printed in each block.) for schematic diagram: All capacitors are in F unless otherwise noted. pF: F 50 WV or less are not indicated except for electrolytics and tantalums. All resistors are in and 1/4 W or less unless otherwise specified. 2 : nonflammable resistor. Note: The components identified by mark 0 or dotted line with mark 0 are critical for safety. Replace only with part number specified. Note: Les composants identifis par une marque 0 sont critiques pour la scurit. Ne les remplacer que par une pice por tant le numro spcifi. NOTE: The mechanical parts with no reference number in the exploded views are not supplied. Items marked * are not stocked since they are seldom required for routine service. Some delay should be anticipated when ordering these items. Color Indication of Appearance Parts Example : KNOB, BALANCE (WHITE). (RED) R R Parts Color Cabinets Color Accessories are given in the last of this parts list. The components identified by mark 0 or dotted line with mark. 0 are critical for safety. Replace only with part number specified. Les composants identifis par une marque 0 sont critiques pour la scurit. Ne les remplacer que par une pice portant le numro spcifi.

Semiconductor Location Ref. No. D101 D102 D201 D202 D801 D802 D803 D851 D852 D901 D902 D903 D904 D951 D952 D953 D954 IC801 IC802 IC803 IC851 IC901 LD801 Q101 Q102 Q103 Q104 Q105 Q106 Q107 Q108 Q109 Q110 Q111 Q112 Q201 Q202 Q203 Q204 Q205 Q206 Q207 Q208 Q209 Q210 Q211 Q212 Q801 Q802 Q803 Q851 Q852 Q853 Q901 Q902 Q903 Q904 Q951 Q952 Q953 Q954 Location G-10 G-9 G-7 G-6 F-11 E-11 F-11 E-10 F-5 D-10 D-11 D-9 D-8 B-7 B-6 D-4 D-3 E-3 F-3 H-3 E-10 D-8 F-14 F-6 G-10 G-9 G-10 G-9 I-10 H-9 H-10 H-9 J-10 J-9 G-9 G-5 G-6 G-6 G-7 G-6 I-6 H-6 H-7 H-6 J-7 J-6 G-5 E-11 E-12 F-13 E-10 E-12 E-12 D-10 D-10 B-9 B-10 C-4 C-4 C-4 C-4
A : B+ Line. B : B Line. Power voltage is dc 14.4V and fed with regulated dc power supply from +12V and REM terminals. Voltage is dc with respect to ground under no-signal condition. Voltages are taken with a VOM (Input impedance 10 M). Voltage variations may be noted due to normal production tolerances. Waveforms are taken with a oscilloscope. Voltage variations may be noted due to normal production tolerances. Circled numbers refer to waveforms. Signal path. F : AUDIO for printed wiring boards: X : parts extracted from the component side. : Pattern from the side which enables seeing.
IC Block Diagram IC901 PC494GS-T1

REF. REG. 10 9

0.1V ERROR 5 OSC

Ref. No. 6

Part No. 3-240-641-01 3-238-672-01 3-238-671-01 3-238-671-11 3-238-673-01
Description PLATE, BOTTOM PANEL, FRONT HEAT SINK (CHINESE MADE) HEAT SINK (JAPAN MADE) PANEL, REAR

Remark

Ref. No. F901
Part No. 7-685-545-14 3-240-642-01 3-225-183-01 3-225-184-01 3-912-432-01
Description SCREW +BTP 3X6 TYPE2 N-S HEAT SINK (SUB 2CH) SCREW (+PSW.TT.3XL) SCREW (+PS.TT.3X6) SCREW (+B)
A-3274-223-A AMP BOARD, COMPLETE 7-685-646-79 SCREW +BVTP 3X8 TYPE2 IT-3
1-532-732-11 FUSE (BLADE TYPE) (AUTO FUSE) 20A