General; Location Of Controls; Diagrams; Note For Printed Wiring Boards And Schematic Diagrams - Sony SA-WM250 Service Manual

LOCATION OF CONTROL
A B
1
Amplifier
SPEAKER
INPUT
INPUT
L L
L L
R R
IN OUT SPEAKER IN
SPEAKER R R
IN OUT
SPEAKER
This subwoofer
D E
F
Amplifier
This subwoofer POWER indicator
MONO OUT
INPUT
POWER
Precautions Hooking Up the System
Overview
On safety
Use the INPUT jacks or the SPEAKER IN terminals of the
• Before operating the subwoofer, be sure that the
subwoofer when you connect the amplifier.
operating voltage of your subwoofer is identical with
• If your amplifier has one of the following types of
that of your local power supply.
output jacks, connect the INPUT jack and the
• Unplug the subwoofer from the wall outlet if it is not to
amplifier's jack using the supplied audio connecting
be used for an extended period of time. To disconnect
cord.
the cord, pull the cord by grasping the plug. Never
— MONO OUT jack
pull the cord itself.
— MIX OUT jack
• Should any liquid or solid object fall into the
— SUBWOOFER output jack(s)
subwoofer, unplug the subwoofer and have the
subwoofer checked by qualified personnel before — SUPER WOOFER output jack(s)
operating it any further.
• AC power cord must be changed only at the qualified • If your amplifier does not have the above mentioned
service shop. output jacks, connect the speaker terminals of the
amplifier to the SPEAKER IN terminals instead. (A)
When turning on or off an amplifier or other
equipment
Before you get started
Lower the volume of the amplifier to minimum.
• Turn off the power of the amplifier and the subwoofer
before making any connection.
To avoid damaging the subwoofer
• Use the audio connecting cords that are supplied to
• Be careful in setting the volume control of the amplifier
the respective equipment. If there are not enough
to avoid an excessive input power.
audio connecting cords to make the necessary
• Do not attempt to open the enclosure or remold
connections, you need to purchase some optional
speaker units and networks.
audio connecting cords.
In case color irregularity is observed on the • Be sure to make connections firmly to avoid noise.
nearby TV screen • Connect the AC power cord from the subwoofer to
a wall outlet.
With the magnetically shielded type of the speaker
• You cannot connect the CENTER output jack for use
system, the speakers can be installed near a TV set.
with Dolby Pro Logic function to the subwoofer.
However, color irregularity may still be observed on the
TV screen depending on the type of your TV set. Bass sound is not output with some Dolby Pro Logic
modes.
If color irregularity is observed...
t Turn off the TV set once, then turn it on after 15 to
Connecting to an amplifier with a
30 minutes.
single set of speaker terminals (B)
If color irregularity is observed again...
If your amplifier is equipped with a single set of speaker
t Place the speakers further apart from the TV set.
terminals, connect the subwoofer to the amplifier, and
then connect the front speakers to the subwoofer.
When howling occurs
Hookups
Relocate the speaker or turn down the volume of the
amplifier.
1
Connect the subwoofer to the amplifier.
On installation
Connect the SPEAKER IN terminals of the
• Do not install the subwoofer near heat sources such as
radiators or air ducts, or in a place subject to direct subwoofer to the amplifier's speaker
terminals with the speaker cords. Be sure to
sunlight, excessive dust, mechanical vibration or shock.
• Good ventilation is essential to prevent internal heat connect both L and R channels.
build-up in the subwoofer. Place the subwoofer in a
location with adequate air circulation. Do not place the 2
Connect the front speakers to the subwoofer.
subwoofer on a soft surface.
Connect the speakers to the SPEAKER OUT
• Use caution when placing the speaker on a specially
terminals of the subwoofer.
treated (waxed, oiled, polished, etc.) floor, as staining
or discoloration may result.
On cleaning the cabinet
Connecting to an amplifier with
Clean the cabinet with a soft cloth lightly moistened with
double (A+B) sets of speaker
water. Do not use any type of abrasive pad, scouring
powder or solvent such as alcohol or benzine. terminals (C)
If your amplifier has double (A+B) sets of speaker
If you have any questions or problems concerning your terminals, connect both the subwoofer and the front
subwoofer that is not covered in this manual, please speakers to the amplifier.
consult your nearest Sony dealer.
Hookups
1
Connect the front speakers to the amplifier.
Installation
Connect the speakers to your amplifier's
SPEAKER A terminals.
Since the human ear cannot detect the direction and
position where the bass sound being reproduced by a
2
subwoofer (below 200 Hz) comes from, you can install Connect the subwoofer to the amplifier.
the subwoofer wherever you like in your room. To
Connect the SPEAKER IN terminals of the
obtain a better bass reproduction, we recommend you
subwoofer to the amplifier's SPEAKER B
to install the subwoofer on a solid floor where the
terminals using the supplied speaker cords.
resonance is unlikely to occur.
Notes
When using the double (A+B) sets of speakers, make
• Always install the subwoofer vertically, keeping a few
sure that you select the "A+B" position with your
centimeters away from the wall.
amplifier.
• Do not place an object on the subwoofer or sit on it.
Note
• If the subwoofer is installed in the center of a room, the
bass could be extremely weakened. This is due to the When you are using SPEAKER A terminal (front
speaker) only or when the power of the amplifier is
influence of the standing wave of the room. If this
happens, move the subwoofer away from the center of turned off, turn down the volume or turn off the power
a room or eliminate the cause of the standing wave, by of the subwoofer. Otherwise, hum noise may be heard.
installing a bookshelf on the wall, etc.
SECTION 1

GENERAL

This section is extracted
from instruction manual.
C
2
1
2
Amplifier
This subwoofer
SPEAKER A
L L
R R
IN OUT
SPEAKER
Front Speaker (R) Front Speaker (L)
Front Speaker (R) Front Speaker (L)
G
1
2
120Hz 150Hz
PHASE
2 1
NORMAL 200Hz
PHASE
REVERSE
100Hz
CUT OFF FREQ
200Hz 3 50Hz
4
75Hz
Foot pads
50Hz
CUT OFF FREQ
LEVEL
MAX
L L
MIN
R R
IN OUT
LEVEL
Connecting to an amplifier with a
Adjusting the Sound (F)
special jack for a subwoofer
If your amplifier has a special jack for a subwoofer (such
You can adjust the sound of the subwoofer to suit the
as MONO OUT jack, MIX OUT jack, SUBWOOFER jack
or SUPER WOOFER jack), connect the INPUT jack of the sound of your front speakers. Reinforcing the bass sound
gives you a greater sense of atmosphere.
subwoofer to one of those jacks.
Hookups (D)
1
Adjust the cut-off frequency.
Connect the MONO OUT jack of your amplifier to the
Turn the CUT OFF FREQ control, depending
INPUT jack of the subwoofer with the supplied audio
on the reproduction frequencies of your front
connecting cord.
speakers.
Note
Refer to the following when adjusting.
If the output level of your amplifier is not large enough,
1 Typical very small sized speakers: 5 – 7 cm
the sound may not be loud enough. In this case, connect
dia.
the speaker terminals of the amplifier directly to the
SPEAKER IN terminals of the subwoofer.
2 Typical small sized speakers: 8 –15 cm dia.
3 Typical medium sized speakers: 16 –24 cm
Connecting the AC power cord
dia.
• Connect the AC power cord from the subwoofer and
4 Typical large sized speakers: more than 25
from your amplifier to a wall outlet.
cm dia.
• Make sure that power to the subwoofer is turned off
before you plug in or unplug any power cord. To make the most of the low level converter
function of Dolby digital, turn the CUT OFF
FREQ as high as possible when playing back
Listening to the Sound (E) the Dolby digital.
2
Adjust the volume level of the subwoofer.
1
Turn on the amplifier and select the program Turn the LEVEL control so that you can hear
the bass sound a little more than before. To
source.
increase the volume, turn the LEVEL control
clockwise. To reduce the volume, turn the
2
Press POWER.
LEVEL control counterclockwise.
The subwoofer turns on and the POWER
indicator lights up in green. 3
Play your favorite song and movie.
Male vocal tunes and voice containing bass
3
Play the program source.
sounds are most suitable for adjustment.
Turn the volume for front speakers to the
Adjust the VOLUME so that sound from the
same level as usual.
front speakers is not distorted.
If it is distorted, the sound from the
4
subwoofer will also be distorted. Select the phase polarity.
Use the PHASE selector to select the phase
polarity.
Notes
5
Repeat steps 1 to 4 to adjust for your
• Never set the amplifier's tone control (BASS, TREBLE,
preference.
etc.) or the equalizer output to a high level or input
sinewaves of 20 Hz to 50 Hz recorded on a Once you have adjusted the subwoofer to the
commercially-available test disc or special sound (bass
settings you want, use the VOLUME control
sound of electronic musical instrument, pop noise of
on the amplifier to adjust the volume of the
analog disc turntable, sound with abnormally
subwoofer with that of the other speakers.
enhanced bass, etc.) in a high level to this unit. These
You don't need to adjust the subwoofer
actions may cause damage to the speakers.
settings when you change the volume level
When a special disc containing abnormally enhanced
of the amplifier.
bass is played, noise may be output in addition to the
original sound. In such a case, reduce the sound level.
• The subwoofer output signal (DOLBY digital signal)
of the digital surround processor sold singularly is set
Notes
10 dB higher by Dolby laboratories Licensing
• If the sound distorts when you turn on the bass
Corporation. In the case of using normally, adjust the
reinforcement from your amplifier (such as, DBFB,
subwoofer level.
GROOVE, the graphic equalizer, etc.), turn off the bass
reinforcement and adjust the sound.
• Do not turn the volume of the subwoofer to maximum.
Doing so may weaken the bass sound. Moreover,
extraneous noise may be heard.
• Selecting NORMAL or REVERSE with the PHASE
selector reverses the polarity and may provide better
bass reproduction in certain listening environments
(depending on the type of front speakers, the position
of the subwoofer and the adjustment of the cut-off
frequency). It may also change the expanse and
tightness of sound, and effect the feeling of the sound
field. Select the setting that provides the sound you
prefer when listening in your normal listening position.
Setting the speaker (
To prevent speaker vibration or movement while
listening, attach the supplied foot pads to the speaker.

2-1. NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS

THIS NOTE IS COMMON FOR PRINTED WIRING
BOARDS AND SCHEMATIC DIAGRAMS.
Amplifier
(In addition to this, the necessary note is printed
SPEAKER B
in each block.)
For schematic diagrams.
L L
Note:
R R
• All capacitors are in µF unless otherwise noted. pF: µµF
IN OUT
SPEAKER
This subwoofer 50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in Ω and
specified.
• f : internal component.
• C : panel designation.
Note:
The components identi-
fied by mark 0 or dotted
line with mark 0 are criti-
cal for safety.
Replace only with part
number specified.
• A : B+ Line.
• B : B– Line.
• Voltages are dc with respect to ground under no-signal
(detuned) conditions.
no mark : Power on
• Voltages are taken with a VOM (Input impedance 10 MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
• Signal path.
F
: AUDIO
• Abbreviation
CND : Canadian model.
MY : Malaysia model.
SP : Singapore model.
TW : Taiwan model.

2-2. CIRCUIT BOARDS LOCATION

)
G
3 3
SECTION 2

DIAGRAMS

For printed wiring boards.
Note:
• X : parts extracted from the component side.
• Y : parts extracted from the conductor side.
• : Pattern from the side which enables seeing.
1 / W or less unless otherwise
• Abbreviation
4
CND : Canadian model.
MY : Malaysia model.
SP : Singapore model.
Note:
Les composants identifiés par
une marque 0 sont critiques
pour la sécurité.
Ne les remplacer que par une
piéce por tant le numéro
spécifié.
INPUT CONTROL board
MAIN board
SWITCH board
SA-WM250
CONTROL board
POWER TRANS board