Sennheiser Satellite Radio SR 3254 User Manual

SR 3254  
SR 3256  
Instructions for use  
4
SR 3254  
SR 3256  
 
Safety instructions  
These instructions for use contain important safety  
information.  
Read these instructions.  
Keep these instructions in a safe place. Always include these  
instructions when passing the device on to third parties.  
Heed all warnings.  
Follow all instructions.  
Operation  
Use the device in dry rooms only. To reduce the risk of fire or  
electric shock, do not expose the device to rain or moisture.  
Objects filled with liquids, such as vases or coffee cups, must not  
be placed on the device. Do not use the device near water or  
liquids.  
Never spill liquids of any kind onto the device. Should a spillage  
occur, unplug the device and have it checked by a technician.  
Never push objects of any kind through openings of this device  
as they may touch dangerous voltage points or short-out parts  
that could result in fire or electric shock.  
Ensure sufficient ventilation. Do not block any ventilation  
openings. Install in accordance with the manufacturer’s  
instructions.  
Do not install near any heat sources such as central heating  
radiators, electric heaters, stoves, or other devices that produce  
heat (e.g. amplifiers). Keep the device away from direct  
sunlight and similar sources of heat.  
The device is a Class 1 device. It must only be connected to  
properly grounded power outlets.  
This device is supplied with an IEC power cable complete with a  
moulded mains plug. This is for your safety - do not tamper with  
the mains. If the supplied cable does not fit your mains socket,  
please consult a competent electrician for a replacement cable  
2
 
that matches the power output sockets in your country, or to  
replace the obsolete socket with one to current standards.  
This device should be operated only from the type of power  
source indicated on the marking label. lf you are not sure of the  
type of power supply to your building, consult your dealer or  
local power company.  
Do not overload wall outlets and extension cords as this may  
result in fire and electric shock.  
Protect the power cord from being walked on or pinched,  
particularly at plugs, convenience receptacles, and the point  
where they exit from the device.  
Only use attachments/accessories specified by Sennheiser.  
Use only with the mountings specified by Sennheiser. When a  
cart is used, use caution when moving the cart/device  
combination to avoid injury from tip-over.  
Unplug the device during lightning storms or when unused for  
long periods of time.  
Service  
No user serviceable parts inside! Do not attempt to service this  
device yourself as opening or removing covers may expose  
dangerous voltage or other hazards. If devices are opened by  
customers in breach of this instruction, the warranty becomes  
null and void.  
Refer all servicing to qualified service personnel. Servicing is  
required if the device has been damaged in any way, such as  
mains cable or plug damage, liquid has been spilled, objects  
have fallen inside, the device has been exposed to rain or  
moisture, does not operate properly or has been dropped.  
Clean only with dry cloth.  
3
 
Symbols on adhesive labels attached to the device  
The adjoining adhesive label is attached to the devices back.  
The symbols on this label have the following meaning:  
This symbol is intended to alert the user to the presence of un-  
insulated dangerous voltage within the product's enclosure  
that may be of sufficient magnitude to constitute risk of fire or  
electric shock.  
This symbol is intended to alert the user to the risk of electric  
shock if the unit cover or back is removed. There are no service-  
able parts inside. Refer servicing to qualified personnel only.  
This symbol is intended to alert the user to the presence of im-  
portant operating and maintenance instructions in the litera-  
ture accompanying this product.  
Attention! High volume!  
This is  
a
professional transmission system.  
Commercial use is subject to the safety-at-work  
regulations. Sennheiser, as the manufacturer, is  
therefore obliged to expressly point out possible  
health risks arising from use.  
This system is capable of producing sound pressure exceeding  
85 dB(A). 85 dB(A) is the sound pressure corresponding to the  
maximum permissible volume which is by law (in some  
countries) allowed to affect your hearing for the duration of a  
working day. It is used as a basis according to the specifications  
of industrial medicine. Higher volumes or longer durations can  
damage your hearing. At higher volumes, the duration must be  
shortened in order to prevent damage. The following are sure  
signs that you have been subjected to excessive noise for too  
long a time:  
y You can hear ringing or whistling sounds in your ears.  
y You have the impression (even for a short time only) that  
you can no longer hear high notes.  
4
 
Intended use of the transmitter  
Intended use includes  
y having read these instructions especially the  
chapter “Safety instructions”.  
y using the transmitter within the operating conditi-  
ons as described in these instructions.  
Improper use  
Improper use is when you use the transmitter other  
than described in these instructions or when you use  
the transmitter under operating conditions different  
from those described in these instructions.  
5
 
SR 3254/SR 3256 transmitters  
With the wireless in-ear monitoring system, consisting of the  
SR 3254 or SR 3256 stereo transmitter and the EK 3253  
bodypack receiver, musicians, video and sound amateurs,  
reporters/broadcasters, etc. can directly monitor the received  
sound signals without troublesome cables or monitor speakers  
being required. In addition, the system can also be used for any  
application where talkback signals are to be transmitted.  
The system has superb audio quality with an increased signal-  
to-noise ratio and dynamic range due to the inclusion of  
Sennheiser’s HDX noise reduction system.  
The SR 3254 is a single stereo transmitter in a 19" 1 U housing.  
4
SR 3254  
SR 3256  
The SR 3256 consists of two complete stereo transmitters in a  
19" 1 U housing.  
The stereo transmitters have the following features:  
y Easy to use  
y Stereo/mono selector switch  
y Switching bandwidth of 36 MHZ per transmitter  
y Transmission frequencies tunable in steps of 5 kHz  
y HDX noise reduction system with more than 90 dB signal-to-  
noise ratio  
y LC display for frequency, RF output power and deviation  
y Rugged 19" housing with built-in mains unit; supplied with  
rack-mounting kit  
y Suitable for multi-channel applications  
y RF output power of up to 100 mW  
6
 
The channel bank system  
The SR 3254/SR 3256 transmitter is available in five UHF  
frequency ranges:  
Range A:  
Range B:  
Range C:  
Range D:  
Range E:  
518 to 554 MHz  
626 to 662 MHz  
740 to 776 MHz  
786 to 822 MHz  
830 to 866 MHz  
The transmitter has two channel banks with up to 16  
switchable channels each. The channels of the channel bank “F“  
(fixed bank) have been factory-preset to customer-specific  
transmission frequencies. These frequencies cannot be  
changed.  
The channel bank “U” (user bank) allows you to freely select  
and store frequencies.  
Recommended receiver  
y EK 3253  
Delivery includes  
y 1 SR 3254 transmitter or  
1 SR 3256 twin transmitter  
y 1 rack-mounting kit  
y 1 mains cable  
y 1 telescopic antenna (with the SR 3254)  
or  
2 telescopic antennas (with the SR 3256)  
y Instructions for use  
7
 
Overview of operating controls  
³ Headphone output,  
¸ Fuse holder and mains voltage  
¼” (6.3 mm) jack socket  
selection (230 or 115 V)  
¹ 2-pin IEC mains connector  
Ƹ Cable grip for mains cable  
· Headphone volume control  
» LCD bargraph for deviation of the left  
channel (DEV L), with overmodulation  
display (“PEAK”)  
ƹ Programming interface,  
15-pin sub-D socket  
¿ LCD bargraph for deviation of the  
right channel and “MONO” (DEV R), with  
overmodulation display (“PEAK”)  
ƺ Audio input, left (AF IN (L))  
ƻ Audio input, right  
(AF IN (R) + MONO)  
´ LCD bargraph for RF output power (RF)  
² Alphanumeric LC display  
SET button  
Ƽ Type plate  
ƽ Antenna output  
º ̆ button (UP)  
¾ ̄ button (DOWN)  
µ POWER button  
Note:  
Connections and operating controls marked with a star () in the above illustration  
are those for the second transmitter of the SR 3256 twin transmitter.  
8
 
Indications and displays  
ባ ቤ ብ ቦ  
ቩ ቨ  
Alphanumeric display  
FREQUENCY MHZ” display  
CHANNEL” display  
LC dot CHANNEL  
LC dot TUNE  
LC dot MONO/STEREO  
LC dot STEREO (transmitter is set to stereo operation)  
LC dot MONO (transmitter is set to mono operation)  
MUTE display (transmitter is muted)  
6-step bargraph for RF output power  
11-step deviation bargraph  
(two separate bargraphs for the left and right channel)  
Deviation display  
The two bargraphs indicate the deviation of the audio signal  
of the left and right channel. When the transmitter’s audio  
input level is excessively high, “PEAK” lights up.  
Display of the RF output power  
The bargraph indicates the RF output power. During normal  
operation, an RF output power of 100 % is indicated.  
9
 
Preparing the transmitter for use  
Using the transmitter as a stand-alone unit  
Mounting the transmitter feet  
To ensure that the transmitter cannot slip on the surface on  
which it is placed, four self-adhesive soft rubber feet are  
supplied.  
̈ Ensure that the base of the transmitter is clean and free from  
grease before mounting the rubber feet.  
̈ Fix the rubber feet to the base of the transmitter by peeling  
of the safety paper and fitting them as shown in the diagram  
on the left.  
Attention!  
Some furniture surfaces have been treated with varnish,  
polish or synthetics which might cause stains when they  
come into contact with other synthetics. Despite a thorough  
testing of the synthetics used by us, we cannot rule out the  
possibility of staining.  
Connecting the telescopic antenna  
When using the transmitter as a stand-alone unit, connect the  
supplied telescopic antenna ƾ. The telescopic antenna can be  
mounted quickly and easily and is suitable for all applications  
where – good transmission conditions provided – a wireless  
transmission system is to be used without a large amount of  
installation work.  
̈ Connect the telescopic antenna to the BNC socket ƽ at the  
rear of the transmitter.  
̈ Pull the end cap to extend the telescopic antenna.  
Optimum transmission and reception conditions can be  
obtained by using remote antennas (see “Mounting and  
connecting remote antennas” on page 16).  
10  
 
Rack-mounting several transmitters  
You can use the supplied rack mount “ears” to mount the  
transmitter into a 19" rack (1 U). If you wish to mount the  
antennas to the front of the rack, use the GA 3030-AM antenna  
mount (see “Accessories” on page 29).  
When rack-mounting the device, please consider that, during  
operation, the ambient temperature within the rack may  
significantly rise above room temperature. However, the  
ambient temperature within the rack must not exceed the  
temperature limit specified in the specifications.  
When rack-mounting the device, take good care not to affect  
the ventilation required for safe operation or provide additional  
ventilation.  
When rack-mounting the device, ensure that its housing is not  
mechanically loaded and that it is adequately supported at the  
rear, e.g. for transport.  
When connecting the device to the power supply, observe the  
information indicated on the type plate. Avoid circuit  
overloading. If necessary, provide overcurrent protection.  
Ensure a reliable mains ground connection of the device by  
taking appropriate measures.  
When rack-mounting the device, please note that intrinsically  
harmless leakage currents of the individual devices may  
accumulate, thereby exceeding the allowable limit value. As a  
remedy, ground the rack via an additional ground connection.  
11  
 
Setting up the transmitters  
The SR 3254 and SR 3256 transmitters heat up during  
operation.  
y Ventilation in fixed installations  
Ensure sufficient ventilation, especially when the transmitters  
are mounted into a desk or chassis. Provide for a duct of  
sufficient size to ensure a free air flow between the trans-  
mitters.  
y Sufficient ventilation in a rack  
When operating several transmitters in a rack, ensure  
sufficient ventilation or cooling. We recommend not stacking  
more than two transmitter directly one above the other, and  
then providing for a duct of sufficient size to ensure a free air  
flow between the transmitters.  
Rack-mounting the transmitter without mounting the  
antennas to the front of the rack  
̈ Hook the two rack mount “ears” ƿ to the rear of the  
transmitter.  
̈ Secure the rack mount “ears” to the left and right of the  
transmitter using four recessed head screws respectively.  
̈ Slide the transmitter into the 19" rack.  
̈ Secure the rack mount “ears” ƿ to the rack.  
12  
 
Rack-mounting the transmitter and mounting the antennas  
to the front of the rack  
̈ Mount the antenna holders  
to the handles of the  
transmitter as shown in the diagram on the left.  
̈ Hook the two rack mount “ears” ƿ to the rear of the  
transmitter.  
̈ Pull the cables of the antenna holders  
through the holes  
in the rack mount “ears”.  
̈ Secure the rack mount “ears” to the left and right of the  
transmitter using four recessed head screws respectively.  
̈ Connect the cables of the antenna holders to the antenna  
sockets ƽ at the rear of the transmitter.  
̈ Slide the transmitter into the 19" rack.  
̈ Connect the telescopic antennas to the BNC sockets of the  
antenna holders  
.
13  
 
Connecting the transmitter to the mains  
The transmitter can be connected to 230 V or 115 V AC. Before  
you plug the mains connector into the wall socket, please first  
check that the transmitter is set to the correct mains voltage!  
The set voltage is shown at the top of the fuse holder ¸.  
Selecting the mains voltage  
Electric shock hazard!  
WARNING!  
In case of improper handling, you may come  
into contact with electrically conducting parts  
and receive an electric shock when removing  
the fuse holder.  
̈ Before removing the fuse holder, pull out the  
mains connector from the wall socket.  
To select the mains voltage, proceed as follows:  
̈ Disconnect the transmitter completely from the mains by  
pulling out the mains connector from the wall socket.  
̈ Use a screwdriver to loosen the fuse holder ¸.  
̈ Remove the fuse holder with the inserted fuse.  
̈ Turn the fuse holder by 180° and reinsert it.  
The set voltage is shown at the top of the fuse holder.  
14  
 
Connecting the mains cable  
̈ Insert the supplied mains cable into the socket on the  
transmitter and pass the cable through the cable grip.  
Note  
A cable grip is particularly important when the transmitter is  
permanently rack-mounted. Inside the rack there are often a  
large number of cables – a cable grip prevents the cables  
from pulling each other out.  
Using transmitters in a multi-channel system  
You can combine several transmitters to make a multi-channel  
system. To do so, you require an antenna combiner (e.g. the  
AC 3000, see “Accessories” on page 29) which allows you to  
combine the signals of up to four twin receivers onto a single  
antenna (see diagram below). For detailed information on  
setting up a multi-channel system and on connecting the  
transmitters, please refer to the operating manual of the  
antenna combiner.  
ANT  
RF OUTPUT  
8:1  
15  
 
Mounting and connecting remote antennas  
Use a remote antenna when the transmitter position is not the  
best antenna position for optimum transmission. You can  
choose between two antennas (see “Accessories” on page 29):  
y A 2003 UHF passive directional antenna  
y A 1031 passive omni-directional antenna  
A 2003  
Use a low-attenuation 50-Ω cable to connect the antenna to  
the transmitter. Ready-made antenna cables from Sennheiser  
are available as accessories with length of 5 m and 10 m. If  
possible, use a short antenna cable and as little connections as  
possible, since long cables and many connectors lead to an  
attenuation of the antenna signal. Position antennas in the  
same room in which the transmission takes place! Maintain a  
minimum distance of 1 m from metal objects (including  
reinforced concrete walls)!  
A 1031  
Connecting the mixing console  
Connect the mixing console to the XLR-3 sockets AF IN (L) ƺ  
and AF IN (R) + MONO ƻ.  
Note  
Any unit that is only suitable for mono operation must be  
connected to the XLR-3 socket AF IN (R) + MONO ƻ. In this  
case, set the transmitter to mono operation (see “Switching  
between mono and stereo operation” on page 22).  
16  
 
Using the transmitter  
Switching the transmitter on/off  
̈ Press the POWER button ¾ to switch the transmitter on or  
off.  
After switch-on, the LC display is backlit and the last  
transmission frequency set is displayed.  
Until the PLL has locked on the desired transmission frequency,  
the transmitter is muted. “MUTE” appears on the display and  
the LCD bargraph for RF output power (RF) ´ indicates 0 %.  
Note  
The POWER button ¾ works in the secondary circuit of the  
integrated mains transformer, and thus only switches the  
low voltage side. For larger installations with several  
transmitters, a complete mains disconnection can best be  
achieved by a central ON/OFF switch.  
17  
 
Connecting the headphones/monitoring the audio signal  
Attention! High volume!  
Even short exposure to high volume levels can damage your  
hearing! Set the volume for the connected headphones to the  
minimum before putting the headphones on. Do not listen at  
higher volume levels than with loudspeakers.  
̈ Connect headphones with a ¼“ (6.35 mm) stereo jack plug  
to the headphone output ³ to monitor the stereo audio  
signal present at the audio inputs ƺ AF IN (L) and  
ƻ AF IN (R) + MONO.  
Note  
Even during mono operation, the left and right channel are  
reproduced separately via the headphones.  
̈ First, set the volume control to the lowest volume by  
turning it to the left as far as possible. Then gradually turn up  
the volume.  
18  
 
The operating menu of the transmitter  
Via the operating menu, you can quickly and easily change the following settings:  
Menu  
Function of the menu  
TUNE  
Setting a transmission frequency for the channel bank “U”  
(user bank)  
CHANNEL  
Selecting a channel from the channel bank “U” or “F”  
Switching between mono and stereo operation  
MONO/STEREO  
The buttons  
In the operating menu, all settings can be made using the ̆ , ̄ and SET buttons:  
Buttons  
Mode  
Function of the button  
̆/̄  
Display mode Selects a menu.  
Setting mode y Briefly pressing the button:  
The display jumps either forwards or backwards to the  
next setting.  
y Holding down the button (“TUNE” and ”CHANNEL”  
menu):  
The display cycles continuously (“fast search”  
function). The “fast search” function allows you to get  
fast and easily to your desired setting.  
SET  
Display mode Changes to the setting mode of the selected menu.  
Setting mode y Stores the setting and returns to the display mode.  
y In the “TUNE” menu:  
Confirms the selection of the channel for which you  
want to set the frequency.  
Canceling an entry  
When in the setting mode of a menu, you can cancel your entry  
at any time by pressing the ̆ and ̄ buttons simultaneously.  
The cancellation is briefly confirmed on the display with “ESc.”.  
The previous setting is kept and the transmitter returns to the  
display mode.  
19  
 
Overview of the operating menu  
Display mode  
Setting mode  
Press SET  
for 1 sec.  
SET  
: U 1... U 16, F 1... F16  
SET: Selects the channel  
Current channel  
SET  
: Transmission  
frequency in steps of 5 kHz  
Current frequency  
SET  
SET  
Current channel or current  
frequency  
Changing the channel  
: U 1... U 16, F 1... F16  
SET  
SET  
Switching between mono  
and stereo operation  
Current setting  
: Mono, Stereo  
SET  
20  
 
TUNE Selecting the frequencies to be stored in the  
channel bank “U”  
Via the “TUNE” menu, you can freely select the frequencies to  
be stored in the channel bank “U” (user bank).  
̈ Press the ̆/̄ buttons to select the “TUNE” menu. The LC  
dot “TUNElights up.  
̈ Press the SET button to get into the setting mode of the  
TUNE” menu.  
The LC dot “TUNEand the “FREQUENCY MHZ” display ባ  
start flashing.  
Note  
When pressing the SET button for one second, you can use  
the ̆/̄ buttons to select a different channel for which you  
can then change the frequency.  
When you have selected the channel bank “F” and then select  
the “TUNE” menu, the transmitter automatically switches to  
channel 01 of the channel bank “U” and “U.01” appears on the  
display. Otherwise, the current channel of the channel bank “U”  
is displayed.  
̈ Press the ̆/̄ buttons to select the desired transmission  
frequency. Transmission frequencies are tunable in 5-kHz  
steps within a switching bandwidth of 36 MHz max.  
̈ Press the SET button to store your selection. “Sto.” briefly  
appears on the display. While the transmitter changes to the  
new frequency, it is muted.  
21  
 
CHANNEL Selecting a channel from the channel bank “U”  
or “F”  
̈ Press the ̆/̄ buttons to select the “CHANNEL” menu.  
The LC dot “CHANNELand the “CHANNEL” display light  
ቤ ብ  
up.  
̈ Press the SET button to get into the setting mode.  
̈ Press the ̆/̄ buttons to select the desired channel.  
1 Sek.  
̈ Press the SET button to store your selection. “Sto.” briefly  
appears on the display.  
MONO/STEREO Switching between mono and stereo operation  
̈ Press the ̆/̄ buttons to select the “MONO/STEREO” menu.  
The LC dot “MONO/STEREOlights up.  
̈ Press the SET button to get into the setting mode.  
̈ Press the ̆/̄ buttons to select the desired operating mode.  
̈ Press the SET button to store your selection. “Sto.” briefly  
appears on the display.  
22  
 
Care and maintenance  
Cleaning the transmitter  
Water can damage the electronics of  
the transmitter!  
CAUTION!  
Water entering the housing of the transmitter  
can cause a short-circuit and damage the  
electronics.  
̈ Only use a slightly damp cloth to clean the  
transmitter.  
̈ Before cleaning, disconnect the transmitter from the mains.  
̈ If necessary, you can clean the transmitter with a slightly  
damp cloth. Do not use any cleansing agents or solvents.  
Replacing the fuse  
Electric shock hazard!  
WARNING!  
In case of improper handling, you may come into  
contact with electrically conducting parts and  
receive an electric shock when removing the  
fuse holder.  
̈ Before removing the fuse holder, pull out the  
mains connector from the wall socket.  
̈ Disconnect the transmitter completely from the mains by  
pulling out the mains connector from the wall socket.  
̈ Use a screwdriver to loosen the fuse holder ¸.  
̈ Remove the fuse holder with the inserted fuse.  
̈ Replace the fuse by a new fuse with the same rating.  
̈ Reinsert the fuse holder. Make sure to insert the fuse holder  
the correct way round.  
The set voltage is shown at the top of the fuse holder.  
̈ Reconnect the transmitter to the mains and and switch it on  
again.  
23  
 
If the replacement fuse also blows, please contact your local  
Sennheiser agent or send the transmitter, with a precise  
description of the trouble, to a Sennheiser service partner in  
your area. You can find the address of your nearest service  
partner in the enclosed service card or on the Internet at  
service_partner”.  
24  
 
If problems occur ...  
Error checklist  
Problem  
Possible cause  
Possible solution  
No operation indication  
No mains connection  
Check the connections of  
the mains connector  
Fuse is defective  
Replace the fuse  
No RF signal  
Transmitter and receiver  
are not on the same  
channel  
Set transmitter and  
receiver to the same  
channel  
Transmitter is out of  
range  
Change the antenna  
position  
RF signal available,  
no audio signal  
Transmitter is set to  
Deactivate the pilot tone  
evaluation on the receiver  
mono operation and the  
pilot tone evaluation of  
the receiver is activated  
Receiver’s squelch  
Reduce the squelch  
threshold is adjusted too threshold on the receiver  
high  
Audio signal has a high  
level of background  
noise or is distorted  
Transmitter sensitivity is See “Connecting the  
adjusted too low or too  
high  
mixing console” on  
page 16  
If problems occur that are not listed in the above table or if the problems cannot be  
solved with the proposed solutions, please contact your local Sennheiser agent for  
assistance.  
25  
 
Additional information  
HDX noise reduction  
RF link  
Inherent  
noise of  
the RF link  
Transmitter  
Receiver  
Progress you can hear:  
The product family is equipped with HDX, the Sennheiser noise  
reduction system that reduces RF interference. It increases the  
signal-to-noise ratio in wireless audio transmission to more  
than 90 dB.  
HDX is a wideband compander system which compresses the  
audio signal in the transmitter in a 2:1 ratio (related to dB) to  
lift it above the inherent noise floor of the RF link. In the receiver  
the signal is expanded in an identical and opposite way in a 1:2  
ratio to restore the original signal, at the same time reducing  
the RF noise to below the noise floor of the receiver.  
HDX has been specially developed for high quality radio  
microphone systems.  
Note:  
Only transmitters and receivers that are equipped with HDX  
can work correctly with each other. If non HDX equipment  
was mixed with HDX, the dynamic range would be  
drastically reduced and the transmission would sound blunt  
and flat.  
26  
 
Specifications  
RF characteristics  
Frequency ranges  
518–554, 626–662, 740–776, 786–822,  
830–866 MHz  
Transmission frequencies  
1 channel bank with up to 16 factory-preset  
channels  
1 channel bank with up to 16 freely selectable  
channels (frequencies tunable in steps of  
5 kHz)  
Switching bandwidth  
Frequency stability  
Antenna output  
36 MHz  
±10 ppm (-10°C to +55°C)  
BNC socket, 50 Ω  
max. 100 mW  
RF output power  
AF characteristics  
Modulation  
FM stereo working on the pilot tone principle  
Sennheiser HDX  
Noise reduction system  
Nominal/peak deviation  
±24 kHz / ±48 kHz  
MPX pilot tone  
19 kHz / ±5 kHz  
(frequency/deviation)  
AF frequency response  
Headphone output  
40–15,000 Hz  
¼“ (6.35 mm) stereo jack socket,  
200 mW/32 Ω  
Load impedance of  
headphone output  
16 Ω  
AF input  
2 x XLR-3, electronically balanced  
AF input voltage (at nom. deviation) +4 dBu at 1 kHz, internally adjustable  
Signal-to-noise ratio  
> 90 dB(A)  
rms  
(refers to overall link with EK 3253)  
THD  
< 0.9 %  
(at 1 kHz and nominal deviation)  
Note:  
The above data also apply to the second transmitter in the SR 3256.  
27  
 
Overall unit  
Power supply  
115/230 V AC +10% / –15%  
max. 13 W  
Power consumption SR 3254  
Power consumption SR 3256  
max. 23 W  
Dimensions  
436 x 228 x 43 mm (19", 1 U)  
(without rack mount “ears”)  
Weight SR 3254  
Weight SR 3256  
Type approval  
approx. 3,300 g  
approx. 4,000 g  
USA:  
FCC-Part 74.861  
FCC ID: DMOSREK3K  
Canada: RSS-123  
IC: 2099A-SREK3K  
EU:  
ETSI EN 300 454-1/-2  
CE 0682!  
Connector assignment  
SR 3254/SR 3256  
¼“ (6.35 mm) stereo jack plug  
for headphone output  
XLR-3 connector (male)  
2
1
+
3
28  
 
Accessories  
AC 3000-EU Active Antenna combiner Cat. no. 009424  
AC 3000-UK Active Antenna combiner Cat. no. 009410  
AC 3000-US Active Antenna combiner Cat. no. 094409  
A 1031-U Passive omni-directional antenna Cat. no. 004645  
GA 3030-AM Antenna mount Cat. no. 004368  
A 2003 UHF Passive directional antenna Cat. no. 003658  
GZL 1019 A5 BNC-BNC coaxial cable, length 5 m Cat. no. 002325  
GZL 1019 A10 BNC-BNC coaxial cable, length 10 m Cat. no. 002326  
GZV 1019A BNC coupler Cat. no. 002368  
HD 25 Monitoring headphone Cat. no. 002976  
EK 3253 A Monitoring receiver Cat. no. 500522  
EK 3253 B Monitoring receiver Cat. no. 500523  
EK 3253 C Monitoring receiver Cat. no. 500524  
EK 3253 D Monitoring receiver Cat. no. 500525  
EK 3253 E Monitoring receiver Cat. no. 500526  
29  
 
Manufacturer declarations  
Warranty regulations  
The guarantee period for this Sennheiser product is 24 months from the date of purchase. Excluded are  
accessory items, rechargeable or disposable batteries that are delivered with the product; due to their  
characteristics these products have a shorter service life that is principally dependent on the individual  
frequency of use.  
The guarantee period starts from the date of original purchase. For this reason, we recommend that the  
sales receipt be retained as proof of purchase. Without this proof (which is checked by the responsible  
Sennheiser service partner) you will not be reimbursed for any repairs that are carried out.  
Depending on our choice, guarantee service comprises, free of charge, the removal of material and  
manufacturing defects through repair or replacement of either individual parts or the entire device.  
Inappropriate usage (e.g. operating faults, mechanical damages, incorrect operating voltage), wear and  
tear, force majeure and defects which were known at the time of purchase are excluded from guarantee  
claims. The guarantee is void if the product is manipulated by non-authorised persons or repair stations.  
In the case of a claim under the terms of this guarantee, send the device, including accessories and sales  
receipt, to the responsible service partner. To minimise the risk of transport damage, we recommend that  
the original packaging is used. Your legal rights against the seller, resulting from the contract of sale, are  
not affected by this guarantee.  
The guarantee can be claimed in all countries outside the U.S. provided that no national law limits our terms  
of guarantee.  
CE Declaration of Conformity  
This equipment is in compliance with the essential requirements and other relevant provisions of Directives  
1999/5/EC, 89/336/EC or 73/23/EC. The declaration is available on the internet site at  
Before putting the device into operation, please observe the respective country-specific regulations!  
WEEE Declaration  
Your Sennheiser product was developed and manufactured with highquality materials and  
components which can be recycled and/or reused. This symbol indicates that electrical and  
electronic equipment must be disposed of separately from normal waste at the end of its  
operational lifetime.  
Please dispose of this product by bringing it to your local collection point or recycling centre for  
such equipment. This will help to protect the environment in which we all live.  
30  
 
Sennheiser electronic GmbH & Co. KG  
30900 Wedemark, Germany  
Phone +49 (5130) 600 0  
Fax +49 (5130) 600 300  
Printed in Germany  
Publ. 09/06  
513631 / A02  
 

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