DC IN 9V
OFF ON
FILTER
NOISE
1 2 3
CHANNEL
R
B
A
L
AUDIO IN
Setting up the
transmitter
1
Connect the transmitter to audio/video
equipment. Select one of the hookups
below depending on the jack type:
A
To connect to a headphones jack
B
To connect to LINE OUT or REC OUT
jacks
DC IN 9V
OFF ON
FILTER
NOISE
1 2 3
CHANNEL
R
B
A
L
AUDIO IN
To recharge the headphone battery after
use
Since the charger shuts itself off in response to its
internal timer after 24 hours, there is no need to
worry about overcharing.
Charging and using hours
* at 1 kHz, 1 mW + 1 mW output
** The hours required to fully charge empty battery
N
Operating the system
Listening to a program
1
First turn on the audio/video equipment
and start playing.
2
Remove the headphones from the
transmitter.
The transmitter’s power indicator will
light in red.
3
Select the radio frequency with the
CHANNEL selector.
4
When you put on the headphones the
headphone power turns on
automatically.
5
Turn up the volume to a moderate level
with the VOL control.
Press the TUNING button briefly for
automatic tuning of the headphones.
If you do not receive a clear audio signal,
press it again.
Try the above steps 3 and 5 until the
receiving performance becomes better.
C
To connect to TV, etc.
If noise occurs when the transmitter is
connected to the headphone jack of your
TV or VCR, set the NOISE FILTER switch
to ON.
Notes
• If you connect the transmitter to LINE OUT or REC
OUT jack, do not set the NOISE FILTER switch to
ON. Otherwise, the volume will be limited.
• The NOISE FILTER switch effects the sound only in
cases such as connection diagram
C
. In diagrams
A
and
B
, the switch has no effect.
• When the transmitter is placed on or near a TV, it
may pick up a noise. In such case, place the
transmitter away from the TV.
2
Connect the transmitter to an AC outlet
using the supplied AC power adaptor.
Notes
• Use only the supplied AC power adaptor. Do not use
any other AC power adaptor.
Polarity of the plug
• When you connect the connecting cord directly to an
earphone jack, the audio signal will not be output
through the right channel. In such a case, use the
separately sold PC-236HG plug adaptor.
• If the connected equipment has the AVLS (Automatic
Volume Limiter System) function, be sure to turn the
function off when using the transmitter. Otherwise, you
will have to turn up the volume of the headphones, and
that may cause noise.
• Do not place the transmitter near a fluorescent lamp, etc.
when using the system.
* WALKMAN is a registered trademark of Sony
Corporation.
Charging the
headphone battery
Using the headphones for the first
time
When you use the headphones for the first time,
charge the battery in the following manner.
1
Connect the transmitter to a power
source.
2
Place the headphones on the transmitter.
Place the headphones on the transmitter such that
the charging pins on the transmitter engage the
charging contacts on the bottom of the housing.
The charge indicator on the transmitter will light in
green to indicate that the battery is being charged.
Once 24 hours have elapsed since the start of
battery charging, the charger automatically shuts
off, and the green indicator goes out.
DC IN 9V
OFF ON
FILTER
NOISE
1 2 3
CHANNEL
R
B
A
L
AUDIO IN
Operating Instructions
Manual de instrucciones
Wireless Stereo
Headphone System
Sony Corporation © 2001
Printed in Korea
MDR-RF975RK
3-233-606-13(1)
Sending RF signals from the Transmitter
The transmitter starts sending the RF signals
automatically, when it detects audio signals from
the equipment connected.
If it does not detect an audio signal for more than
approximately four minutes, the transmitter will
stop sending RF signals, and the power indicator
turns off.
When the transmitter receives an audio signal
again, it starts sending the RF signals, and the
power indicator will light in red again.
If the audio signal is very weak, the transmitter
does not send RF signals. If the transmitter is
connected to a headphone jack, make sure the
volume of the equipment connected is set to 5 – 6
or higher.
You may not hear the beginning of the sound from
the headphones until the transmitter starts sending
the RF signals after detecting an audio signal.
Note
If the transmitter is connected to the headphones jack of
the source equipment, set the volume of that equipment as
high as possible without distorting the audio signal.
Auto power on/off function
When you remove the headphones from your
head, the power turns off automatically. Do not
allow the self adjusting band to be pulled up,
otherwise the headphones will be switched on.
The power turns on.
Note
If a hissing noise is heard move closer to the transmitter.
After listening to a program
Take the headphones off and rest them away on
the transmitter, and recharge them.
Note
Do not hang the headphones by the self adjusting band,
otherwise, the self adjusting band will be pulled up and
the headphones will be switched on.
The effective areas of
the transmitter
The optimum distance is up to approximately 150
feet (46 m) without the system picking up some
interference. However, the distance may vary
according to the surroundings and environment. If
the system picks up some noise while using it
within the above mentioned distance, reduce the
distance between the transmitter unit and the
headphones, or select the other channel.
Notes
• When you use the headphones inside the effective areas
of the transmitter, the transmitter can be placed in any
direction from the listener.
• Even within the signal reception area, there are some
spots (dead spot) where the RF signal can not be
received. This is a characteristic inherent to RF signals,
and does not indicate malfunction. By slightly moving
the transmitter, location of the dead spot can be
changed.
English
Transmitter
Left channel
(white)
Right channel
(red)
Unimatch plug
adaptor
(supplied)
Discman, MD,
WALKMAN*, VCR,
etc.
to headphones
jack (stereo
mini jack)
Connecting cord
(supplied)
to AUDIO IN
A jacks
to headphones
jack (stereo
phone jack)
TV, etc.
to stereo mini jack
Transmitter
to AUDIO IN
A jack
Left channel
(white)
Right channel
(red)
Connecting cord
(supplied)
Transmitter
to AUDIO IN
B jack
Connecting cord
(supplied)
Right channel
(red)
Left channel
(white)
to LINE OUT or REC
OUT jacks
Stereo system, VCR, etc.
Approx. charging
hours
1
24**
Approx. using time*
60 minutes
25 hours
No sound/Muffled sound
,
Turn on the transmitter first, then put on the
headphones.
,
Check the connection of the audio/video
equipment or the AC power adaptor.
,
Check that the audio/video equipment is turned
on.
,
Turn up the volume on the connected audio/
video equipment, if the transmitter is connected
to the headphones jack.
,
Change the radio frequency with the CHANNEL
selector on the transmitter, then press the
TUNING button again.
,
The mute function is activated.
Use the headphones near the transmitter.
,
The headphones’ POWER indicator light is weak
or turned off.
• Charge the built-in rechargeable battery or if the
POWER indicator is still off after charging the
built-in rechargeable battery, take the
headphones to a Sony dealer for replacement of
the rechargeable battery.
,
If you connect the transmitter to LINE OUT or
REC OUT jack of an audio reproducer, make sure
that the NOISE FILTER switch is set to OFF.
,
Make sure that the NOISE FILTER switch is set to
either ON or OFF (If the switch gets stuck
between ON and OFF, the sound will be cut off).
Distortion
,
If the transmitter is connected to the headphones
jack, turn down the volume of the connected
audio/video equipment.
,
Change the radio frequency with the CHANNEL
selector on the transmitter.
,
The headphones’ POWER indicator light is weak
or turned off.
• Charge the built-in rechargeable battery or if the
POWER indicator is still off after charging the
built-in rechargeable battery, take the
headphone to Sony dealer for replacement of the
rechageable battery.
,
If you connect the transmitter to LINE OUT or
REC OUT jack of an audio reproducer, make sure
that the NOISE FILTER switch is set to OFF.
Loud background noise
,
Move closer to the transmitter. As you move
away from the transmitter, more noise is likely to
be heard.
,
If the transmitter is connected to the headphones
jack, turn up the volume of the connected audio/
video equipment.
,
Change the radio frequency with the CHANNEL
selector on the transmitter, then press the
TUNING button again.
,
The headphones’ POWER indicator light is weak
or turned off.
• Charge the built-in rechargeable battery or if the
POWER indicator is still off after charging the
built-in rechargeable battery, take the
headphone to Sony dealer for replacement of the
rechageable battery.
,
If you connect the transmitter to LINE OUT or
REC OUT jack of an audio reproducer, make sure
that the NOISE FILTER switch is set to OFF.
Specifications
General
Carrier frequency
913.5 – 914.5 MHz
Channel
Ch1, Ch2, Ch3
Modulation
FM stereo
Frequency response
18 – 22,000 Hz
Transmitter TMR-RF975R
Power source
DC 9 V: supplied AC power adaptor
Audio input
phono jacks/stereo mini jack
Dimensions
Approx. 130
×
135
×
150 mm
(5
1
/
4
×
5
3
/
8
×
6 in.) (w/h/d)
Mass
Approx. 200 g (7 oz.)
Headphones MDR-RF975R
Power source
DC 2.4 V: Built-in rechargeable
battery
Mass
Approx. 350 g (12.3 oz.) incl.
built-in rechargeable battery
Built-in Ni-MH rechargeable battery
Model name
NH-AAC
Voltage
1.2 V
Capacity
1,000 mAh
Optional accessory
Plug adaptor
PC-236HG (stereo mini jack
y
monaural mini plug)
Design and specifications are subject to change without
notice.
Troubleshooting
Welcome!
Thank you for purchasing the Sony
MDR-RF975RK Wireless Stereo Headphone
System. Before operating the unit, please read this
manual thoroughly and retain it for future
reference.
Some features are:
• Wireless system that allows you to listen to a
program free from the restriction of a cord
• High fidelity sound reproduction
• A compact transmitter with an AC power
adaptor (supplied) enables simple charging of
the headphone battery. Just by placing the
headphones on the transmitter, headphone
battery can be charged.
• Comfortable Circum-aural headphones with
self-adjusting head band
• Automatic ON/OFF function on headphones to
preserve battery power
to an AC outlet
To DC IN
9 V jack
AC power adaptor
(supplied)
Transmitter
1 2 3
CHANNEL
TUNING
button
VOL control
Replacing the ear
pads
When the ear pads become dirty or damaged, you
can get replacements from your Sony dealer.
Replace them as illustrated below.
1
Remove the old ear pad by pulling it out
of the groove on the housing.
2
Place the new ear pad on the driver unit
and insert the edge of the pad into the
groove as illustrated.
Make sure that the entire edge of the ear pad is
securely inserted into the groove.
N
Additional information
Precautions
• When the transmitter is not to be used for a long
period of time, disconnect the AC power
adaptor from the AC outlet holding the plug. Do
not pull on the cord.
• Do not leave the wireless stereo headphone
system in a location subject to direct sunlight,
heat or moisture.
Notes on headphones
Preventing hearing damage
Avoid using headphones at high volume. Hearing
experts advise against continuous, loud and
extended play. If you experience a ringing in your
ears, reduce the volume or discontinue use.
Caring for others
Keep the volume at a moderate level. This will
allow you to hear outside sounds and to be
considerate to the people around you.
If you have any questions or problems concerning
the system that are not covered in this manual,
please consult the nearest Sony dealer.
Be sure to bring the headphones and the
transmitter to the Sony dealer when requiring
repair work.
Disposing of the headphones
Be sure to remove the built-in rechargeable
batteries from the headphones before you
dispose of the headphones.
First remove the left headphone’s ear pad.
You will see four screws. Remove the four
screws and open the housing.
WARNING
To prevent fire or shock hazard, do not
expose the unit to rain or moisture.
To avoid electrical shock, do not open the
cabinet. Refer servicing to qualified
personnel only.
Information
You are cautioned that any changes or
modifications not expressly approved in this
manual could void your authority to operate this
equipment.
If you have any questions about this product, you
may call:
Sony Customer Information Services Center
1-800-222-7669 or http://www.sony.com/
Declaration of Conformity
Trade Name:
SONY
Model No.:
MDR-RF975R
(Headphones Unit)
Responsible Party: Sony Elecoronics Inc.
Address:
16450 W. Bernardo Dr,
San Diego, CA 92127 USA
Telephone No.:
858-942-2230
This device complies with Part 15 of the FCC
Rules. Operation is subject to the following two
conditions: (1) This device may not cause
harmful interference, and (2) this device must
accept any interference received, including
intereference that may cause undesired
operation.
Owner’s Record
The model number is located at the bottom of the
transmitter and on the inside of the left housing
hanger of the headphones.
The serial number is located at the bottom of the
transmitter and on the backside of the left housing
hanger of the headphones.
Record these numbers in the spaces provided
below. Refer to them whenever you call upon your
Sony dealer regarding this product.
Model No. MDR-RF975RK
Transmitter TMR-RF975R
Headphones MDR-RF975R
Serial No.
Transmitter
Headphones
Notes on receiving
performance
The system for this equipment utilizes very high
frequency signals in the 900 MHz band so the
receiving performance may deteriorate due to the
surroundings. The following examples illustrate
conditions that may reduce the possible receiving
range or cause interference with reception.
• Inside a building with walls containing steel
beams.
• Area with many steel file cabinets, etc.
• Area with many electrical appliances capable of
generating electromagnetic noise.
• Transmitter is placed on a metal instrument.
• Area facing roadways.
• Noise or interfering signals exist in the
surroundings due to radio transceivers in trucks,
etc.
• Noise or interfering signals exist in the
surroundings due to wireless communication
systems installed along roadways.
N
Getting started
Unpacking
Check that you have the following items:
• The headphones
• The transmitter
• AC power adaptor
• Unimatch plug adaptor (stereo mini jack
t
stereo phone plug)
• Connecting cord (phono plugs
y
stereo mini
plug), 1 m
RECYCLING NICKEL METAL HYDRIDE
BATTERIES
Nickel Metal Hydride
batteries are recyclable.
You can help preserve our
environment by returning
your used rechargeable
batteries to the collection and
recycling location nearest
you.
For more information regarding recycling of
rechargeable batteries, call toll free
1-800-822-8837, or visit http://www.rbrc.org/.
Caution:
Do not handle damaged or leaking Nickel
Metal Hydride batteries.
