Sony MDR-RF940RK annexe

Wireless Stereo

3-858-839-41(1)

( Getting started

Unpacking

Check that you have the following
items:

• The transmitter

Notes

•Use only the supplied rechargeable batteries NC­AA (HJ).

•You cannot recharge other R6 (size AA)
rechargeable batteries (NC-AA etc.) with this
unit.

•Use only the supplied AC power adaptor. Do
not use any other AC power adaptor.

Polarity of the plug

Setting up the
headphones

1 Open the battery compartment lid

on the left inner side of the head
band.

Headphone System

Operating Instructions

• AC power adaptor

• Connecting cord (phono plugs ˜
stereo mini jack)

• The headphones

• Ni-Cd rechargeable batteries NC-AA
(HJ)

<ill.>

Setting up the
transmitter

1 Connect the transmitter to audio/

video equipment.

a To connect to a headphones jack

Transmitter

to headphones jack
(stereo mini jack)

2 Insert two charged NC-AA (HJ)

batteries by matching the + and – on
the batteries to the + and – in the
battery compartment.

]

]

}

3 Close the battery compartment lid.

MDR-RF940RK

Sony Corporation © 1996 Printed in Japan

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.

Welcome!

Thank you for purchasing the Sony
MDR-RF940RK 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 within 130 feet
from the transmitter.

• High fidelity sound reproduction

• Compact transmitter which operates
on AC power supplied through the
supplied AC power adaptor and allso
functions as a buttery charger

• Comfortable Circum-aural
headphones

• Automatic ON/OFF function on
headphones to preserve battery power

• Mute function to avoid noise when no
audio signal is available.

Charging the
headphones’
batteries

1 Open the battery compartment lid

on the bottom of the transmitter.

2 Insert two NC-AA (HJ) batteries by

matching the + and - on the batteries
to the + and - in the battery
compartment.

3 Close the battery compartment.

4 Connect the transmitter to a power

source.

Transmitter

to an AC
outlet

To DC IN

4.5V jack

AC power
adaptor
(supplied)

5 Set the OFF/CHG/POWER ON

switch to OFF/CHG.
The OFF/CHG indicator lights up in
green and charging starts.
When the charging complete,
@@@@@

Discman,
Walkman, TV,
VCR, etc.

b To connect to LINE OUT or REC OUT

jacks

Transmitter

Connecting
cord (supplied)

Left channel
(white)

Stereo system,
TV, VCR, etc.

Right
channel (red)

to LINE OUT or
REC OUT

To recharge the headphones’ batteries
after use

To charge the batteries, follow steps in
“Charging the headphones’ batteries.”
Since little electric current is used for
charging, there is no need to worry
about overcharging.

Charging and using hours

Approx. charging
hours

00

00*

* The hours required to fully charge empty

batteries

Using the headphones with a
commercially available R 6 (size AA)
dry batteries

Install the battery in the manner as
described in “Setting up the
headphones.”

Battery life

Battery

Sony alkaline battery LR6
(SG)

Sony battery R6P (SR)

Notes on batteries

To avoid damage to the system caused
by battery leakage and corrosion;
– Install the batteries with the correct

polarity.
– Do not try to recharge the batteries.
– Remove the batteries if the system is

not to be used for a long period of

time.
In case of battery leakage, wipe off any
deposit in the battery compartments
before installing new batteries.

Approx. using
hours

00

00

Approx. hours

40

20

When to replace the batteries

When the POWER indicator dims, and a
hissing noise increases charge the NC­AA (HJ) batteries or replace both
batteries with new ones.

3-858-839-11 (1)

( Operating the system

( Additional information

Listening to a
program

1 Select the radio frequency with the

CHANNEL selector switch.
Select the same channel on the
headphones and the transmitter.

CH2CH1

2 Turn on the audio/video equipment

then the transmitter.

POWER

3 Put on the headphones and the

power turns on automatically.

4 Adjust the volume.

The effective areas
of the transmitter

The optimum distance is up to
approximately 130 feet (40m) 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 point) where the RF signal can
not be received. This characteristics is inherent to
RF signals, and does not indicate malfunction.
By slightly moving the transmitter, location of
the dead point can be changed.

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.

Precautions

• When the headphones are not to be
used for a long period of time, remove
the dry batteries (if any) to avoid
damage caused by battery leakage and
subsequent corrosion.

• 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.
Also remove the batteries to avoid
damage caused by battery leakage and
subsequent corrosion.

• 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.

Troubleshooting

Problem

No sound/
Muffled sound

Distortion

Loud
background
noise

Solution

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.

The mute function is
activated.
Use the headphones near
the transmitter.

Charge the NC-AA (HJ)
batteries or replace both
batteries of the headphones.

If the transmitter is
connected␣ to␣ the␣ headphones
jack, turn down the volume
of the connected audio/
video equipment.

Charge the NC-AA (HJ)
batteries or replace both
batteries of the headphones.

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.

Charge the NC-AA (HJ)
batteries or replace both
batteries of the headphones.

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, the
power turns off automatically. Do not
apply pressure to the left ear pad when
not using the headphones, otherwise the
headphones will be switched on.

/

Mute function

If a hissing noise is heard when the
headphones are used outside of the
effective range (see the next section), the
mute function will be activated and the
sound will not be heard from the
headphones. To restore the sound,
move near toward the transmitter.

2 Place the new ear pad on the

housing 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.

Specifications

General

Carrier frequency

000 – 000 MHz

Channel Ch1, Ch2
Modulation FM stereo

Frequency response

20 – 20,000 Hz

Transmitter

RF Power Less than 94 dBµV/m at 3 m

Power source DC 4.5 V: supplied AC power

Audio input stereo mini plug

Dimensions Approx. 90 mm dia x 35 mm

Mass Approx. 200 g (7.1 oz.)

Headphones

Power source DC 3 V: 2 x R6 (size AA) battery

Mass Approx. 270 g (9.5 oz.) incl.

Optional accessories

Plug adaptor PC-236HG
(stereo mini jack ˜ monaural mini plug)

Design and specifications are subject to change
without notice.

adaptor

5

/8 x 17/16 in.) (w/h)

(3

incl.batteries

batteries

When no audio signal is received for
more than approximately five
minutes

The transmitter will be burned off
automatically.

After listening to a program

Take the headphones off before turning
off the transmitter. If you turn off the
transmitter first, you may hear some
noise.