Sony XM-444 Service manual
XM-444
SERVICE MANUAL
Ver 1.0 2002. 02
SPECIFICATIONS
Circuit system OTL (output transformerless) circuit Pulse
Inputs RCA pin jacks
Input level adjustment range
Outputs Speaker terminals
Speaker impedance 2 – 8 Ω (stereo)
Maximum outputs
4 Speakers: 80 W × 4 (at 4 Ω)
3 Speakers: 80 W × 2 + 222 W × 1 (at 4 Ω)
2 Speakers: 222 W × 2 (at 4 Ω)
Rated outputs (supply voltage at 14.4 V)
4 Speakers: 35 W × 4 (20 Hz – 20 kHz, 0.04% THD, at 4 Ω)
2 Speakers: 80 W × 2 (20 Hz – 20 kHz, 0.1% THD, at 4 Ω)
Frequency response 5 Hz – 80 kHz ( dB)
Harmonic distortion 0.005% or less (at 1 kHz, 4 Ω, 10 W)
Low-pass filter 80 Hz, –18 dB/oct
High-pass filter 80 Hz, –12 dB/oct
Power requirements 12 V DC car battery
Power supply voltage 10.5 – 16 V
Current drain at rated output : 20 A (4 Ω, 35 W × 4)
Dimensions Approx. 260 × 55 × 180 mm (w/h/d) not incl.
Mass Approx. 2.4 kg not incl. accessories
Supplied accessories Mounting screws (4)
Design and specifications are subject to change without
notice.
power supply
High level input connector
0.3 – 6 V (RCA pin jacks),
0.6 – 12 V (High level input)
4 – 8 Ω (when used as a bridging amplifier)
40 W × 4 (20 Hz – 20 kHz, 0.1% THD, at 2 Ω)
+0
–3
(negative ground)
Remote input : 1.5 mA
projecting parts and controls
High level input cord (1)
Protection cap (1)
AEP Model
UK Model
E Model
9-873-560-01
2002B0400-1
© 2002. 02
STEREO POWER AMPLIFIER
Sony Corporation
e Vehicle Company
Published by Sony Engineering Corporation
1
XM-444
PROTECTOR OPERATION CHECK
Thermal Protect
1. Short across TH801 with the power on.
2. Verify that the protector is operated and LD801 illuminates red.
3. Verify that the protector is released and LD801 illuminates green
when the short is removed.
4. Likewise, perform items 1 to 3 for TH802 and TH803.
Over Current Protect
1. Short between the positive and negative sides of the speaker
output terminal CN802 with the power on.
(Perform this shorting for each channel on FRONT and REAR.)
2. Verify that the protector is operated and LD801 illuminates red.
3. Verify that the protector is not released and LD801 remains red
even when the short is removed.
4. Verify that the protector is released and LD801 illuminates green
when the power is turned off and then on again.
Offset Protect
1. Short between the +12V terminal of CN801 and the BTL+ or
BTL– of the speaker output terminal CN802.
(Short between +12V terminal and BTL+ and between +12V
terminal and BTL–.)
2. Verify that the protector is operated and LD801 illuminates red.
3. Verify that the protector is not released and LD801 remains red
even when the short is removed.
4. Verify that the protector is released and LD801 illuminates green
when the power is turned off and then on again.
TABLE OF CONTENTS
1. GENERAL
Connections ............................................................................. 3
2. DISASSEMBLY
2-1. Bottom Plate ........................................................................ 5
2-2. Heat Sink ............................................................................. 6
2-3. Amp Board .......................................................................... 6
3. DIAGRAMS
3-1. Block Diagram –Front Section– ......................................... 7
3-2. Block Diagram –Rear/Power Section– ............................... 8
3-3. Schematic Diagram –Amp Section– ................................... 9
3-4. Schematic Diagram –Power Section– ............................... 10
3-5. Printed Wiring Board ........................................................ 11
4. EXPLODED VIEW ........................................................... 12
5. ELECTRICAL PARTS LIST......................................... 13
Chassis Short Protect
1. Short between the +12V terminal of CN801 and the chassis with
the power on.
2. Verify that the pilot lamp PL801 goes on.
3. Verify that PL801 goes off when the short is removed.
Notes on Chip Component Replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE
WITH MARK 0 ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR
IN SUPPLEMENTS PUBLISHED BY SONY.
2
SECTION 1
GENERAL
XM-444
This section is extracted
from instruction manual.
3
XM-444
4
SECTION 2
6
DISASSEMBLY
Note : This set can be disassemble according to the following sequence.
SET
2-1. BOTTOM PLATE
(Page 5)
2-2. HEAT SINK
(Page 6)
2-3. AMP BOARD
(Page 6)
XM-444
Note : Follow the disassembly procedure in the numerical order given.
2-1. BOTTOM PLATE
3
bottom plate
2
BTP 3x6
1
BTP 3x
5
XM-444
8
2-2. HEAT SINK
2
BVTP 3x8
3
BVTP 3x8
1
BVTP 3x8
5
heat sink
4
AMP board
2-3. AMP BOARD
4
front panel
5
AMP board
2
rear panel
1
BVTP 3x
3
BVTP 3x8
6
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