Sennheiser SI 30 User manual

9
SI 30
INSTRUCTIONS FOR USE

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BRIEF DESCRIPTION
Infra-red two-channel modulator used in conjunction with Sennheiser
infra-red receivers to set up a cordless sound transmission system.
• SI 30 infra-red two-channel modulators have sufficient IR capacity
to cover rooms of up to 80 m2(mono) or 40 m2(stereo).
• SI 30 infra-red two-channel modulators are an integral part of
Sennheiser´s modular design concepts which allow added flexibility
in the setting up of cordless sound transmission systems.
A list of available accessories comes with the SI 30.
FEATURES
• Automatic on/off function
• Operation indicator (green LED)
• Mode selection switch for selection of carrier frequencies
• Automatic volume control
• RF output for connection of infra-red radiators
SUITABLE INFRA-RED RECEIVERS FROM SENNHEISER
RI 150, RI 250, RI 250-J, RI 300, RI 500, RI 250-S, HDI 302, HDI 380
11 infra-red diodes
Operation indicator,
green LED

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INSTALLATION
• Position the modulator as high as possible (eye-level). Make sure
that the diodes point at the receivers.
• Do not cover the diodes! Do not obstruct the path of the light
between the modulator and the receiver.
MAINS CONNECTION
Connect the NT 20 plug-in mains unit to the mains. Plug the cable into
power supply socket (S) on the SI 30. Pay attention to the correct
direction of the plug.
AF CONNECTION
Use the AF connection cable to connect the AF input (N) on the SI 30 to
the headphone socket of the sound source.
Please contact your nearest dealer if your sound source has no
3.5 mm or 6.3 mm socket.
RF OUTPUT FOR CONNECTION OF INFRA-RED RADIATORS
Connect SZI 1029, SZI 1015 or SZI 30 infra-red radiators to provide
sufficient IR capacity for larger rooms. The SZI 1029, SZI 1015 and
SZI 30 connect to the 3.5 mm mono jack socket (Z) on the SI 30
modulator (please see list of available accessories).
Power supply socket
(S)
Mode selection switch (B)
Channel 1, 2, Stereo
RF output (Z) for
connection of
infra-red radiators
AF input (N)

∞
III
∞
III
∞
III
R
LL L
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ADJUSTMENTS ON YOUR SOUND SOURCE
Set the volume of your sound source to a medium value.
NOTE
Some modern television sets have a separate volume control
for the headphone socket. Please refer to the instruction
manual of your television set.
Although the socket for the connection of a tape recorder (e.g. on the
amplifier of a PA system) cannot be regulated, it usually delivers a signal
voltage which is sufficient to operate the SI 30 modulator.
MODE SELECTION SWITCH
CHANNEL 1, 2, STEREO/SELECTION OF THE CARRIER FREQUENCY
The mode selection switch (B) at the rear of the SI 30 serves to select
the infra-red carrier frequency. Please note that in mono mode only the
tip of the strereo jack plug is used (see diagram):
During mono operation the SI 30´s IR capacity is twice as high as during stereo operation!
Stereo or
two-channel mode
Mono
Channel 1 (2.3 MHz)
Mono
Channel 2 (2.8 MHz)
Connection to
mono sockets
Connection to
mono sockets
Connection to
stereo sockets

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ON/OFF SWITCH
The SI 30 modulator and the NT 20 plug-in mains unit have no
ON/OFF switch. The green LED at the front of the SI 30 indicates
that the modulator is ready for operation.
In standby mode, the SI 30’s current consumption is very low.
However, unplug the mains unit when you are not going to use the
SI 30 for some time.
AUTOMATIC ON/OFF FUNCTION
The SI 30 features a convenient automatic on/off function. When an
audio signal reaches the modulator, it is switched on (L 1 lights up). If
there is no audio signal for about 3 to 4 minutes, the modulator
automatically switches off.
The automatic on/off function depends on a certain threshold voltage.
If the signal voltage falls below this threshold, the modulator auto-
matically switches off after 3 minutes (L 1 goes off). In this case,
increase the volume on your sound source (please see paragraph
“Adjustments on your sound source”).
DELIVERY INCLUDES
• 1 SI 30 modulator
• 1 AF connection cable with 3.5 mm mono jack plug
• 1 3.5 mm/1/4” jack adaptor
ACCESSORIES (to be ordered separately)
• Please see list of available accessories
• 1 NT 20 plug-in mains unit (120 V, 230 V or 240 V) for
powering the SI 30 or for powering the SI 30 in conjunction
with SZI 30 infra-red radiators.

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TECHNICAL DATA
Mode selection switch: I mono channel 1
II mono channel 2
∞ stereo channel 1+2
Modulation FM
Carrier frequencies channel 1: 2.3 MHz
channel 2: 2.8 MHz
Nominal deviation ± 50 kHz
Emitting diodes 11
Pre-emphasis 50 µ s
Audio frequency response 30 - 18,000 Hz
THD
(1 kHz and nominal deviation) ≤ 1 %
Signal-to-noise ratio ≥ 74 dBArms
≥ 63 dB as per CCIR 468
Volume control automatic
AF connection 3.5 mm ø jack plug with
adaptor to 1/4”(6.3 mm)
RF output for connection
of infra-red radiators 3.5 mm mono jack socket
Input voltage for
nominal deviation 45 mV- 4 V
Automatic on/off function yes
Input voltage for automatic
on/off function > 45 mV
Operation indicator green LED
Operating voltage 24 - 27 V DC
Current consumption 180 mA
Power consumption (standby) approx. 3.5 VA
Dimensions approx. 118 x 25 x 90 mm
Weight approx. 140 g
Subject to alterations. Errors and omissions excepted.