Sony SAWMSP-2 Service manual

SA-WMSP2/WMSP4

SERVICE MANUAL

Ver 1.0 2002. 02

• SA-WMSP2 is the sub woofer section in
HT-DDW740.

• SA-WMSP4 is the sub woofer section in
HT-DDW840.

POWER OUTPUT AND TOTAL
HARMONIC DISTORTION:

With 6 ohm loads, from 28 – 200 Hz; rated 100
watts (SA-WMSP4) / 50 watts (SA-WMSP2),
minimum RMS power, with no more than 0.8%
total harmonic distortion from 250 milliwatts to
rated output (Models of area code U only).

Speaker system Active subwoofer,

Speaker unit Woofer: 20 cm cone type
Enclosure type Acoustically loaded bass

Continuous RMS power output
(6 ohms, 20 – 250 Hz)

SA-WMSP4 100 W
SA-WMSP2 50 W

Reproduction frequency range

High frequency cut-off frequency

Input LINE IN (input pin jacks)

magnetically shielded

reflex

28Hz – 200 Hz

150 Hz

photo: SA-WMSP4 silver model

SPECIFICATION

Canadian Model

AEP Model

Power requirements

Area code Power requirements

U, CA, MX 120 V AC, 60 Hz
CEL, CEK, SP, MY 230 V AC, 50/60 Hz
AR 220 – 230 V AC, 50/60 Hz
E2/E3 120/220/230 V AC, 50/60 Hz

Power consumption

SA-WMSP4 100 W
SA-WMSP2 50 W

Dimensions (w/h/d) Approx. 272 326 405

Mass

SA-WMSP4 10.0 kg (22 lb 1 oz)
SA-WMSP2 9.0 kg (19 lb 14 oz)

• Abbreviation

AR : Argentin model
CA : Canadian model
CEK : UK model
CEL : AEP model
MX : Mexican model
MY : Malaysia model
SP : Singapore model
U : US model

mm (10 3/4 12 7/8 16
inches) including front
panel

US Model

UK Model

E Model

9-873-478-01

2002B1600-1

© 2002.02

ACTIVE SUBWOOFER

Sony Corporation

Home Audio Company

Published by Sony Engineering Corporation

SA-WMSP2/WMSP4

SAFETY CHECK-OUT

After correcting the original service problem, perform the
following safety checks before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs, screws,
and all other exposed metal parts for A C leakage. Check leakage as
described below.

LEAKAGE

The AC leaka ge from any exposed metal part to earth g round and
from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microamperes).
Leakage current can be measured by any one of three methods.

1. A commercial leakage tester, such as the Simpson 229 or RCA
WT -540A. Follo w the manufacturers’ instructions to use these
instruments.

2. A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.

3. Measuring the voltage drop across a resistor by means of a
VOM or battery-operated AC v oltmeter . The “limit” indication
is 0.75 V, so analog meters must have an accurate low-v oltage
scale. The Simpson 250 and Sanwa SH-63Trd are e xamples of
a passive VOM that is suitable. Nearly all battery operated
digital multimeters that have a 2V AC range are suitable. (See
Fig. A)

To Exposed Metal
Parts on Set

0.15µF

Ω

1.5k

Earth Ground

AC
voltmeter
(0.75V)

Fig. A. Using an AC voltmeter to check AC leakage.

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.

ATTENTION AU COMPOSANT AYANT RAPPORT

À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFÉS PAR UNE MARQUE 0 SUR LES
DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES SONT
CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE
REMPLACER CES COMPOSANTS QUE PAR DES PIÈSES SONY
DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPÉMENTS PUBLIÉS PAR SONY.

2

SECTION 1

DIAGRAMS

THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)

SA-WMSP2/WMSP4

Note on Printed Wiring Boards:

• X : parts extracted from the component side.

• Y : parts extracted from the conductor side.

• b : Pattern from the side which enables seeing.

Note on Schematic Diagram:

• All capacitors are in µF unless otherwise noted. p: pF. 50
WV or less are not indicated except for electrolytics and
tantalums.

• 2 : nonflammable resistor.

• 5 : fusible resistor.

• All resistors are in Ω and
specified.

• C : panel designation.

The components identified by
mark 0 or dotted line with mark
0 are critical for safety.
Replace only with part number
specified.

• A : B+ Line.

• B : B– Line.

• Voltages are dc with respect to ground under no-signal
conditions.
no mark : Power on

• Voltages are taken with a VOM (Input impedance 10MΩ).
Voltage variations may be noted due to normal preduction
tolerances.

• Signal path.
F : AUDIO

• Abbreviation
AR : Argentin model.
CND : Canadian model.
MX : Mexican model.
MY : Malaysia model.
SP : Singapore model.

1

4

/

W or less unless otherwise

Les composants identifiés par
une marque 0 sont critiques
pour la sécurité.
Ne les remplacer que par une
pièce portant le numéro spécifié.

3

SA-WMSP2/WMSP4

d

• CIRCUIT BOARD LOCATION

SWITCH board

LED board

INPUT JACK board

MAIN board

POWER TRANS boar

CONTROL board

4