LD PRE ST 1 User manual

PRE ST 1
4-CHANNEL STEREO MIXER PREAMPLIFIER
LDPREST1
USER´S MANUAL
BEDIENUNGSANLEITUNG
MANUEL D´UTILISATION
MANUAL DE USUARIO
INSTRUKCJA OBSŁUGI
MANUALE D´USO
ОГЛАВЛЕНИЕ

ENGLISH
INTENDED USE 5
SAFETY INFORMATION 5
INTRODUCTION 8
FEATURES 8
CONNECTIONS, CONTROLS AND DISPLAY ELEMENTS9
PRIORITY LEVELS 14
CONNECTION EXAMPLES 14
TERMINAL BLOCK CONNECTIONS 15
RACK INSTALLATION 16
UNDER-TABLE INSTALLATION 18
CARE, MAINTENANCE AND REPAIR 19
TECHNICAL DATA 20
DISPOSAL 23
MANUFACTURER’S DECLARATIONS 23
DEUTSCH
INFORMATIONEN ZU DIESER BEDIENUNGSANLEI-
TUNG 24
BESTIMMUNGSGEMÄSSER GEBRAUCH 24
BEGRIFFS- UND SYMBOLERKLÄRUNGEN 24
SICHERHEITSHINWEISE 25
HINWEISE FÜR INDOOR-INSTALLATIONSGERÄTE 28
LIEFERUMFANG 28
EINLEITUNG 29
FEATURES 29
ANSCHLÜSSE, BEDIEN- UND ANZEIGEELEMENTE 30
PRIORITY-EBENEN 35
ANSCHLUSSBEISPIELE 36
KLEMMLEISTENANSCHLÜSSE 37
RACK-MONTAGE 38
UNTERTISCH-MONTAGE 39
PFLEGE, WARTUNG UND REPARATUR 40
TECHNISCHE DATEN 41
ENTSORGUNG 45
HERSTELLERERKLÄRUNGEN 45
FRANÇAIS
UTILISATION PRÉVUE 46
INFORMATIONS DE SÉCURITÉ 46
INTRODUCTION 49
CARACTÉRISTIQUES 49
CONNEXIONS, DISPOSITIFS DE COMMANDE ET
D’AFFICHAGE 50
NIVEAUX DE PRIORITÉ 55
EXEMPLES DE BRANCHEMENTS 55
CONNEXIONS BORNIER 56
MONTAGE EN RACK 57
MONTAGE SOUS UNE TABLE 59
ENTRETIEN, MAINTENANCE ET RÉPARATIONS 60
CARACTÉRISTIQUES TECHNIQUES 61
ÉLIMINATION 64
DÉCLARATIONS DU FABRICANT 64
ESPAÑOL
USO PREVISTO 65
INFORMACIÓN DE SEGURIDAD 65
INTRODUCCIÓN 68
CARACTERISTICAS 68
CONEXIONES, CONTROLES Y ELEMENTOS DE VISUALI-
ZACIÓN 69
NIVELES DE PRIORIDAD 74
EJEMPLOS DE CONEXIÓN 74
CONEXIONES DEL BLOQUE DE TERMINALES 75
INSTALACIÓN EN RACK 76
INSTALACIÓN DEBAJO DE LA MESA 78
CUIDADO, MANTENIMIENTO Y REPARACIÓN 79
DATOS TÉCNICOS 80
ELIMINACIÓN 83
DECLARACIONES DEL FABRICANTE 83
CONTENTS / INHALTSVERZEICHNIS / SOMMAIRE / CONTENIDO / SPIS TREŚCI / SOMMARIO / 

CONTENTS / INHALTSVERZEICHNIS / SOMMAIRE / CONTENIDO / SPIS TREŚCI / SOMMARIO / 
POLSKI
PRZEZNACZENIE 84
INFORMACJE DOTYCZĄCE BEZPIECZEŃSTWA 84
WSTĘP 87
WŁAŚCIWOŚCI 87
ZŁĄCZA, KONTROLKI IWYŚWIETLANE ELEMENTY 88
POZIOMY PRIORYTETU 93
PRZYKŁADOWE PODŁĄCZENIA 93
ZŁĄCZA LISTWY ZACISKOWEJ 94
MONTAŻ W SZAFIE RACK 95
MONTAŻ PODBLATOWY 97
PIELĘGNACJA, KONSERWACJA I NAPRAWA 98
DANE TECHNICZNE 99
UTYLIZACJA 102
OŚWIADCZENIA PRODUCENTA 102
ITALIANO
USO PREVISTO 103
INFORMAZIONI SULLA SICUREZZA 103
INTRODUZIONE 106
CARATTERISTICHE 106
COLLEGAMENTI, CONTROLLI ED ELEMENTI DEL
DISPLAY 107
LIVELLI DI PRIORITÀ 112
ESEMPI DI COLLEGAMENTI 112
CONNESSIONI DELLA MORSETTIERA 113
INSTALLAZIONE RACK 114
INSTALLAZIONE SOTTO-BANCO 116
CURA, MANUTENZIONE E RIPARAZIONE 117
DATI TECNICI 118
SMALTIMENTO 121
DICHIARAZIONI DEL PRODUTTORE 121
РУССКИЙ
ЦЕЛЕВОЕ НАЗНАЧЕНИЕ 122
ИНФОРМАЦИЯ ПО ТЕХНИКЕ
БЕЗОПАСНОСТИ 122
ВСТУПЛЕНИЕ 125
ФУНКЦИОНАЛЬНЫЕ ОСОБЕННОСТИ 125
СОЕДИНЕНИЯ, УПРАВЛЕНИЕ И ЭЛЕМЕНТЫ
ДИСПЛЕЯ 126
УРОВНИ ПРИОРИТЕТА 131
ПРИМЕРЫ ПОДКЛЮЧЕНИЯ 131
СОЕДИНЕНИЯ КЛЕММНЫХ КОЛОДОК 132
УСТАНОВКА В СТОЙКУ 133
УСТАНОВКА ПОД СТОЛЕШНИЦЕЙ 135
УХОД, ТЕХНИЧЕСКОЕ ОБСЛУЖИВАНИЕ И
РЕМОНТ 136
ТЕХНИЧЕСКИЕ ХАРАКТЕРИСТИКИ 137
УТИЛИЗАЦИЯ 140
ДЕКЛАРАЦИИ ПРОИЗВОДИТЕЛЯ 140

5
ENGLISH
YOU‘VE MADE THE RIGHT CHOICE!
We have designed this product to operate reliably over many years. LD Systems stands for this with its
name and many years of experience as a manufacturer of high-quality audio products. Please read this
User‘s Manual carefully, so that you can begin making optimum use of your LD Systems product quickly.
You can find more information about LD-SYSTEMS at our Internet site WWW.LD-SYSTEMS.COM
INTENDED USE
This product is a device for professional audio installation! The product has been developed for profes-
sional use in audio installations and is not suitable for use in private homes!
In addition, this product must only be used by qualified persons with technical knowledge of audio ins-
tallations! The product must not be used outside the specified technical data and operating conditions!
Any liability for damage and third-party damage to persons and property is excluded if the product is
not used as intended! The product is not suitable for:
• Persons (including children) with limited physical, sensory or mental capabilities or lack of experience
and knowledge.
• Children (children must be instructed not to play with the device).
SAFETY INFORMATION
1. Please read these instructions carefully.
2. Keep all information and instructions in a safe place.
3. Follow the instructions.
4.
Observe all safety warnings. Never remove safety warnings or other information from the equipment.
5. Use the equipment only in the intended manner and for the intended purpose.
6. Use only sufficiently stable and compatible stands and/or mounts (for fixed installations). Make
certain that wall mounts are properly installed and secured. Make certain that the equipment is
installed securely and cannot fall down.
7. During installation, observe the applicable safety regulations for your country.
8.
Never install and operate the equipment near radiators, heat registers, ovens or other sources of heat.
Make certain that the equipment is always installed so that is cooled sufficiently and cannot overheat.
9. Never place sources of ignition, e.g., burning candles, on the equipment.
10. Ventilation slots must not be blocked.
11. Keep a minimum distance of 20 cm around and above the device.
12. Do not use this equipment in the immediate vicinity of water (does not apply to special outdoor
equipment - in this case, observe the special instructions noted below. Do not expose this equip-
ment to flammable materials, fluids or gases. Avoid direct sunlight!
13. Make certain that dripping or splashed water cannot enter the equipment. Do not place containers
filled with liquids, such as vases or drinking vessels, on the equipment.
14. Make certain that objects cannot fall into the device.
15. Use this equipment only with the accessories recommended and intended by the manufacturer.
16. Do not open or modify this equipment.
17. After connecting the equipment, check all cables in order to prevent damage or accidents, e.g., due
to tripping hazards.
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18. During transport, make certain that the equipment cannot fall down and possibly cause property
damage and personal injuries.
19.
If your equipment is no longer functioning properly, if fluids or objects have gotten inside the equipment
or if it has been damaged in another way, switch it off immediately and unplug it from the mains outlet
(if it is a powered device). This equipment may only be repaired by authorized, qualified personnel.
20.Clean the equipment using a dry cloth.
21. Comply with all applicable disposal laws in your country. During disposal of packaging, please sepa-
rate plastic and paper/cardboard.
22. Plastic bags must be kept out of reach of children.
23. Please note that changes or modifications not expressly approved by the party responsible for
compliance could void the user´s authority to operate the equipment.
FOR EQUIPMENT THAT CONNECTS TO THE POWER MAINS
24.
CAUTION: If the power cord of the device is equipped with an earthing contact, then it must be connec-
ted to an outlet with a protective ground. Never deactivate the protective ground of a power cord.
25. If the equipment has been exposed to strong fluctuations in temperature (for example, after trans-
port), do not switch it on immediately. Moisture and condensation could damage the equipment. Do
not switch on the equipment until it has reached room temperature.
26.
Before connecting the equipment to the power outlet, first verify that the mains voltage and frequency
match the values specified on the equipment. If the equipment has a voltage selection switch, connect
the equipment to the power outlet only if the equipment values and the mains power values match. If
the included power cord or power adapter does not fit in your wall outlet, contact your electrician.
27. Do not step on the power cord. Make certain that the power cable does not become kinked, especial-
ly at the mains outlet and/or power adapter and the equipment connector.
28.When connecting the equipment, make certain that the power cord or power adapter is always
freely accessible. Always disconnect the equipment from the power supply if the equipment is not
in use or if you want to clean the equipment. Always unplug the power cord and power adapter from
the power outlet at the plug or adapter and not by pulling on the cord. Never touch the power cord
and power adapter with wet hands.
29.Whenever possible, avoid switching the equipment on and off in quick succession because other-
wise this can shorten the useful life of the equipment.
30.IMPORTANT INFORMATION: Replace fuses only with fuses of the same type and rating. If a fuse blows
repeatedly, please contact an authorised service centre.
31. To disconnect the equipment from the power mains completely, unplug the power cord or power
adapter from the power outlet.
32. If your device is equipped with a Volex power connector, the mating Volex equipment connector
must be unlocked before it can be removed. However, this also means that the equipment can slide
and fall down if the power cable is pulled, which can lead to personal injuries and/or other damage.
For this reason, always be careful when laying cables.
33. Unplug the power cord and power adapter from the power outlet if there is a risk of a lightning
strike or before extended periods of disuse.
34. The appliance is not to be used by persons (including children) with reduced physical, sensory or
mental capabilities, or lack of experience and knowledge.
35. Children must be instructed not to play with the device.
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36. If the power cord of the device is damaged, do not use the device. The power cord must be replaced
by an adequate cable or assembly from an authorized service center.
CAUTION:
To reduce the risk of electric shock, do not remove cover (or back). There
are no user serviceable parts inside. Maintenance and repairs should be
exclusively carried out by qualified service personnel.
The warning triangle with lightning symbol indicates dangerous uninsulated voltage inside
the unit, which may cause an electrical shock.
The warning triangle with exclamation mark indicates important operating and maintenance
instructions.
Warning! This symbol indicates a hot surface. Certain parts of the housing can become hot
during operation. After use, wait for a cool-down period of at least 10 minutes before hand-
ling or transporting the device.
Warning! This device is designed for use below 2000 metres in altitude.
Warning! This product is not intended for use in tropical climates.
FOR INDOOR USE ONLY
This symbol indicates electrical equipment designed primarily for indoor use.
CAUTION! HIGH VOLUMES IN AUDIO PRODUCTS!
This device is meant for professional use. Therefore, commercial use of this equipment is subject to the
respectively applicable national accident prevention rules and regulations. As a manufacturer, Adam Hall is
obligated to notify you formally about the existence of potential health risks.
Hearing damage due to high volume and prolonged exposure: When in use, this product is capable of produ-
cing high sound-pressure levels (SPL) that can lead to irreversible hearing damage in performers, emplo-
yees, and audience members. For this reason, avoid prolonged exposure to volumes in excess of 90 dB.
NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against
harmful interference in a residential installation. This equipment generates, uses and can radiate radio
frequency energy and, if not installed and used in accordance with the instructions, may cause
harmful interference to radio communications. However, there is no guarantee that interference will
not occur in a particular installation. If this equipment does cause harmful interference to radio or tele-
vision reception, which can be determined by turning the equipment off and on, the user is encouraged
to try to correct the interference by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
• Consult the dealer or an experienced radio/TV technician for help.
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INTRODUCTION
Permanent installations require solutions which offer a visually discrete design that blends into the
background while still being exible and versatile in their functions. You need to be able to connect
different audio sources and manage them, to mute non-priority signals during announcements or
emergency calls.
The PRE ST 1 is a 4-channel multi-functional stereo mixer preamplier that allows users to mix 2 micro-
phone/line sources together with an emergency line input and one of the 3 music sources available,
including a Bluetooth receiver. These versatile connection options together with a four-level priority
system, that combines contact closure inputs and VOX audio detection circuits, guarantees a seamless
integration in almost any commercial audio application.
PRE ST 1 is equipped with two priority contacts: one for the emergency input, which mutes all the other
signal sources, and one for the microphone inputs, which mutes the music signal sources. The stereo
balanced line output includes a mono/stereo switch and separate tone controls for bass and treble. An
automatic standby mode can also be activated in order to further reduce energy consumption when
the device is not used.
The intuitive design of its control panel ensures an easy operation, with input and master volume
controls, clear signal level and priority indications, and a practical music source selection and Blue-
tooth pairing activation via capacitive buttons. On the other hand, the clarity of the rear panel and the
compact 9.5” format ensures that the preamplier can be easily installed.
FEATURES
• Line input for emergency signal with contact closure
• 2 Mic/line input terminal blocks with microphone/line switching and switchable 24-V phantom power
• Priority contact closure and switchable chime function for mic/line channels
• 3 stereo music sources: 2 line inputs with RCA sockets plus Bluetooth 4.0 interface
• Gain control and Clip LED for emergency and Mic/Line inputs
• Balanced stereo line output (terminal block) with mono-stereo switching
• Separate tone controls for treble and bass on the rear panel
• 4 priority settings for versatile integration options
• Switchable auto standby mode to save energy
• User-friendly control interface - intuitive operation via capacitive controller (choice of music source
and Bluetooth pairing)
• Easy installation thanks to the clear layout and labeling of the connections and controls on the back
• Universal wide-range switching power supply
• Format: Half rack width, 2 RU
• Optional: Rack installation kit (IMA RK) for the installation of one or two PRE ST1 or IMA 30/60 units in
a 19” rack
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CONNECTIONS, CONTROLS AND DISPLAY ELEMENTS
+ -/G
1
3
2
XLR m 1
3
2
XLR m
2
6
3
8
9
57 4
1
1POWER CONNECTOR
IEC socket to the power supply of the device (power cable included in the packaging).
2FUSE
Fuse holder for 250V fuses (5 × 20mm). IMPORTANT NOTE: Only replace the fuse with a fuse of the same
type (see note on the housing). If the fuse blows repeatedly, please contact an authorized service center.
3ON/OFF
Rocker switch to turn the device on and off.
4EMERGENCY
5-pole terminal block connection for the installation of an acoustic emergency call system. The poles
+, - and G correspond to a balanced line input. Poles C and + are used for the connection of a separate
mute switch (terminal block included in the packaging). The contact closure of the EMERGENCY channel
(Poles C and + closed) mutes all other input channels, regardless of the VOX settings.
CLIP: The red CLIP LED indicates the input is being operated at the distortion limit. You should reduce
the signal level using the GAIN control or the volume control on the playback device so that the CLIP LED
is no longer lit.
VOX: The VOX control (Voice Operated Exchange) makes it possible to set a threshold for the emergency
audio signal in order to activate an automatic mute switching circuit. When the level at the EMERGENCY
input reaches the set threshold, all other microphone and line channels are muted. This ensures that
the emergency signal can be heard clearly. In addition, in this case the EMERG indicator is lit on the
front of the amplifier. As soon as the level of the emergency signal falls below the set threshold,
the other channels are no longer muted and the EMERG indicator goes out. With this setting, the
EMERGENCY channel always has the highest priority. The emergency signal is routed directly to the
audio output LINE OUT internally.
If the VOX control is set to minimum (turned all the way to the left), automatic muting via the VOX
switching circuit is deactivated and the EMERGENCY channel can be used as an additional line channel.
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GAIN: Control to set the pre-amplification of the corresponding audio signal. Set the Gain control such
that the Clip LED of the channel only lights up briefly when the signal level peaks. Avoid the Clip LED
being permanently lit by reducing the pre-amplification. It may also be necessary to reduce the signal
level on the playback device. The level of the emergency signal is not influenced by the current setting
of the main volume control (master volume), but is set via the GAIN control.
5MIC/LINE 1
Microphone/line channel with switchable chime function (signal tone). The connection can be made via
the XLR/jack combo socket as well as the terminal block. In this case, the poles +, - and G are provided
on the terminal block connection for the balanced input signal.
Poles C and + are used for the connection of a separate mute switch (terminal block included in the
packaging). The contact closure offers the possibility to mute the MUSIC channel using an external
switch/button. In addition, the internal chime/signal tone function can be activated in this way when
the circuit is enabled (see point 6 MIC/LINE 2, CHIME).
MIC/LINE: If there is a line signal on the XLR/jack combo socket or the terminal block, switch the MIC/
LINE channel 1 to LINE mode using the corresponding MIC/LINE switch (switch pressed). If a microphone
is connected, activate MIC mode using the MIC/LINE switch (switch not pressed).
PHANTOM ON/OFF: When using a condenser microphone, you need to activate the 24 V phantom power
supply (PHANTOM ON/OFF switch pressed: ON). Always make sure that the microphone is connected
and the channel volume is set to minimum before turning on phantom power. Before you disconnect
the microphone from the device again, deactivate the phantom power and turn the channel volume to
minimum.
GAIN: Control to set the pre-amplification of the corresponding audio signal. Set the Gain control such
that the Clip LED of the channel only lights up briefly when the signal level peaks. Avoid the Clip LED
being permanently lit by reducing the pre-amplification. It may also be necessary to reduce the signal
level on the playback device.
CLIP: The red CLIP LED indicates the input is being operated at the distortion limit. You should reduce
the signal level on the GAIN control or the volume control on the playback device so that the CLIP LED is
no longer lit.
VOX: The VOX control makes it possible to set an audio threshold value for an automatic mute circuit
for MIC/LINE input 1, that mutes MIC/LINE 2 and MUSIC channels as soon as its input signal reaches the
predefined level. The PRIO LED is lit on the front if the contact closure or VOX circuit is activated. As soon
as the input level of the emergency signal falls below the set threshold, the channels are no longer
muted and the PRIO LED goes out. In such a configuration, MIC/LINE 1 has priority over MIC/LINE 2 and
MUSIC. Adjust the volume of the channel using control 1 on the front of the device.
6MIC/LINE 2
Microphone/line channel with switchable chime function (signal tone). The connection can be made
via the RCA sockets (line level, a stereo signal is summed to mono) as well as the terminal block. In this
case, the poles +, - and G are provided on the terminal block connection for the balanced input signal.
MIC/LINE: If there is a line signal on the terminal block connection, switch the MIC/LINE channel 2 to
LINE mode using the corresponding MIC/LINE switch (switch pressed). If a microphone is connected to
the terminal block connection, activate MIC mode using the MIC/LINE switch (switch not pressed).
PHANTOM ON/OFF: When using a condenser microphone, you need to activate the 24 V phantom power
supply (PHANTOM ON/OFF switch pressed: ON). Always make sure that the microphone is connected
and the channel volume is set to minimum before turning on phantom power. Before you disconnect
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the microphone from the device again, deactivate the phantom power and turn the channel volume to
minimum.
GAIN: Control to set the pre-amplification of the corresponding audio signal. Set the Gain control such
that the Clip LED of the channel only lights up briefly when the signal level peaks. Avoid the Clip LED
being permanently lit by reducing the pre-amplification. It may also be necessary to reduce the signal
level on the playback device.
CLIP: The red CLIP LED indicates the input is being operated at the distortion limit. You should reduce
the signal level on the GAIN control or the volume control on the playback device so that the CLIP LED is
no longer lit.
CHIME: The volume for the chime/signal tone is controlled via the CHIME control on the back of the
amplifier. If the control is turned all the way to the left, the chime/signal tone circuit is disabled. If the
internal chime/signal tone function is active, MIC/LINE 1, MIC/LINE 2 and MUSIC channels are muted
for the duration of the signal tone. The signal tone is initiated with the help of a button which is
connected to contacts C and + of the MIC/LINE 1 channel.
Adjust the volume of the channel using control 2 on the front of the device.
7MUSIC
Stereo line channel for the connection of playback devices such as a CD or MP3 player. The MUSIC
channel includes a Bluetooth module. RCA sockets are provided on the back for connecting two stereo
line input signal sources (CD symbol or cable symbol). The desired signal source is selected using a
touch-sensitive button on the front of the amplifier. Adjust the volume of the channel using control
MUSIC on the front of the device.
8LINE OUT
The balanced stereo line output LINE OUT with terminal block connection is used to send the audio
output signal to an external amplifier or active loudspeaker system. Pin assignment: LEFT +, LEFT -, G
(Ground), RIGHT +, RIGHT - (terminal block in packaging content).
BASS/TREBLE: The tone settings of the output signal can be applied by using the BASS and TREBLE
controls.
ST/MONO: The output of the audio signal can either be in stereo (ST) or in mono (MONO). If the switch is
set to MONO, the corresponding audio signal is summed to mono at both outputs LEFT and RIGHT.
9STANDBY ON/OFF
If the standby function is activated (STANDBY in ON position), the amplifier is automatically set to
standby mode if there is no audio signal for 20 minutes. This reduces power consumption considerably.
As soon as there is an audio signal, standby mode is automatically ended and the amplifier is once
again operational after around 3 seconds (the STANDBY LED flashes white on the front of the device
when starting). If the STANDBY LED is solid white, the device is ready for use. The LED is lit red in standby
mode. In addition, the device can also be switched to standby mode manually by pressing the standby
button on the front. In this case, auto standby mode is deactivated and the device no longer starts
automatically.
Please note: The standby circuit analyses the connection status of the Bluetooth unit. When a Bluetoo-
th connection to an auxiliary device (smartphone, tablet) is detected, and Bluetooth is selected as the
signal source, the device will not automatically go into standby mode.
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10
11
13 14
12
15
16 17
19
18
10 CHANNEL 1
Volume control for channel 1 with white SIG (signal) and red CLIP LED. As soon as there is an audio signal
on channel 1 and volume control 1 is set to the desired volume, the white signal LED lights up. If the red
CLIP LED lights up, the signal may be distorted. In this case, reduce the channel volume control (control
1). Should the audio signal still be distorted, please check the corresponding input level on the back of
the amplifier (CLIP LED/GAIN).
11 CHANNEL 2
Volume control for channel 2 with white SIG (signal) and red CLIP LED. As soon as there is an audio
signal on channel 2 and volume control 2 is set to the desired volume, the white signal LED lights up. If
the red CLIP LED lights up, the signal may be distorted. In this case, reduce the channel volume (control
2). Should the audio signal still be distorted, please check the corresponding input level on the back of
the amplifier (CLIP LED/GAIN).
12 MUSIC
Volume control for MUSIC channel with white SIG (signal) and red CLIP LED. As soon as there is an audio
signal on the MUSIC channel and the corresponding volume control is set to the desired volume, the
white signal LED lights up. If the red CLIP LED lights up, the signal may be distorted. In this case, reduce
the output level of the auxiliary device or the channel volume (MUSIC control).
13
Touch-sensitive button for selecting the audio source of the MUSIC channel (Bluetooth module, input
with CD symbol, input with cable symbol). To switch over the signal source, press the button for at least
half a second. Activation of the individual signal sources takes place clockwise.
14
Touch-sensitive button for activating the Bluetooth connection (pairing). To connect a Bluetooth auxi-
liary device (e.g. Smartphone, tablet, etc.) to the Bluetooth module of the device, select the Bluetooth
signal source (see element 13). If no auxiliary device is connected to the Bluetooth module, this is
indicated by the Bluetooth symbol flashing slowly. In this mode, the LD PRE ST1 is not visible to external
auxiliary devices. Only previously connected auxiliary devices can be connected directly to the LD PRE
ST1 without activating pairing mode. In order to prevent an unwanted or unexpected connection, this
connection is not established automatically, but must be manually established in the Bluetooth menu
of the auxiliary device (select LD PRE ST1).
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To connect to a new auxiliary device, press the Bluetooth pairing button for around 2 seconds until
the Bluetooth symbol flashes more rapidly. The Bluetooth ID is now visible to other Bluetooth devices.
Activate the Bluetooth function on the auxiliary device and search for nearby Bluetooth devices in
the Bluetooth menu. When the LD PRE ST1 appears under “available devices”, you just need to select it
and the connection will be made automatically. If this process is successful, the Bluetooth symbol is
permanently lit on the front of the device and the Bluetooth ID is no longer visible to other devices. This
prevents unauthorized connections to the Bluetooth module. Playback from the auxiliary device can
now be started. To disconnect a currently paired Bluetooth device and to set the Bluetooth module rea-
dy to pair again, press the Bluetooth icon for around 2 seconds. Pair the playback device and connect it
again by selecting LD PRE ST1 from “paired devices” in the Bluetooth menu of the playback device.
15 MASTER VOLUME CONTROL
The master volume control is used to adjust the volume of the summed signal of all channels except
the EMERGENCY channel. The EMERGENCY channel bypasses the master volume control, and the signal is
sent directly to the stereo line output, LINE OUT. The master volume control is equipped with a ring-sha-
ped LED display. This LED ring remains dark when there is no signal or only a very weak signal at the
output, and starts to light up white as soon as a sufficient signal level is detected.
16 PRIO
LED for the indication of an active priority mode related to MIC/LINE channels (priority levels 2, 3 and 4).
Three situations cause the priority feature of the MIC/LINE channels to engage, thereby causing the
PRIO display field on the front of the device to light up yellow.
1. The VOX circuit is active (input signal level MIC/LINE 1 exceeds the set VOX threshold value).
2. The contact between poles C and + of the terminal block connections for MIC/LINE 1 channel is closed
using a mute switch/button.
3. The chime/signal tone is played.
Further information on the channel priorities and the EMERG and PRIO indicators on the front of the
amplifier can be found in the PRIORITY LEVELS table in these operating instructions.
17 EMERG
Indicator for the priority function of the EMERGENCY channel. The EMERG indicator is lit yellow if priority
level 1 is activated by the VOX emergency circuit or a connected mute switch/button (contact closure).
All other input channels are muted during this time. As soon as the contact closure is opened again or
the emergency signal level falls below the VOX threshold value, all channels will be unmuted, and the
EMERG display will be turned off.
18 STANDBY BUTTON
Briefly press the standby button to put the preamplifier into standby mode and mute the stereo line
output, LINE OUT. If the standby button is briefly pressed again, the device is ready for operation again.
If standby mode is activated by pressing the standby button, reactivation of the device via the auto-
matic standby function is not available, even if an audio signal is detected.
DEUTSCHFRANÇAIS
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14
PRIORITY LEVELS
Priority
level
Trigger source Muted signal
sources
Active
signal
sources
Indication
in the front
panel
1Emergency VOX circuit and
Contact closure
MIC/LINE 1
EMERGENCY EMERGMIC/LINE 2
MUSIC
2MIC/LINE 1 VOX MIC/LINE 2 EMERGENCY PRIO
MUSIC MIC/LINE 1
3MIC/LINE 1, contact closure during
chime/signal tone output
MIC/LINE 1
EMERGENCY PRIOMIC/LINE 2
MUSIC
4MIC/LINE 1, contact closure after
chime/signal tone output MUSIC
EMERGENCY
PRIOMIC/LINE 1
MIC/LINE 2
5– –
EMERGENCY
–
MIC/LINE 1
MIC/LINE 2
MUSIC
CONNECTION EXAMPLES
Microphone Signal
Microphone Signal
Mute Contact
Mute Contact
Call Station 2 Call Station 1
Call Station
Player 1 Player 2
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15
The connection for a mute switch/button in MIC/LINE channel 1 can be used for two devices at the same
time (muting of a music signal and/or activation of the chime/signal tone). In this case, the mute cont-
acts of both devices must be connected to poles C and + of the terminal block connector for MIC/LINE 1.
Microphone Signal
Microphone Signal
Mute Contact
Mute Contact
Call Station 2 Call Station 1
Call Station
Player 1 Player 2
When wiring terminal blocks, please ensure that the poles/terminals are correctly assigned.
The manufacturer takes no responsibility for damage caused by faulty wiring! Information
on the correct wiring of terminal block connections can be found in the section TERMINAL
BLOCK CONNECTIONS in this user manual.
TERMINAL BLOCK CONNECTIONS
EMERGENCY CHANNEL CONNECTIONS MIC/LINE 1 CONNECTIONS
+ -/G
1
3
2
XLR m 1
3
2
XLR m
+ -/G
1
3
2
XLR m 1
3
2
XLR m
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16
MIC/LINE 2 CONNECTIONS
+ -/G
1
3
2
XLR m 1
3
2
XLR m
balanced unbalanced
LINE OUT CONNECTIONS
+ -/G
1
3
2
XLR m 1
3
2
XLR m
RACK INSTALLATION (LDIMARK rack installation kit available as an option)
The optionally available LDIMARK rank installation kit contains rack-mount brackets and connecting
pieces for fixed installation of PRE ST 1, IMA 30 and IMA 60 mixing amplifiers (single or two side by side)
in a 19” rack. The installation kit includes the following components:
2 rack-mount brackets with short sides A, 1 rack-mount bracket with long side B, 2 small plates for
the back C, 2 rectangular plates for the bottom D, 4 M4 flathead screws for the rack-mount brackets,
8 M3 countersunk screws for the plates D.
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17
AA B
C
D
The installation of a single amplifier requires one rack-mount bracket with short side Aand the rack-
mount bracket with long side B. Screw the bracket with the short sides to either the left or right side
of the amplifier and the bracket with the long side to the opposite side. Use the M4 flathead screws for
this.
AB
If you want to install two amplifiers side by side in a 19” rack, you will need the two small plates to
connect the amplifiers together at the back C, the two rectangular plates for connection at the bot-
tom Dand the two rack-mount brackets with short side A. Loosen the corresponding screws on the
back and secure the plates with these screws C. Screw the connecting plates Din with the supplied
M3 countersunk screws to the intended positions on the amplifiers, as shown below. Screw the rack-
mount brackets with the short side Ato the sides of the device using the M4 flathead screws.
V1
05.06.2019
PRODUCTNAME
A A
B B
C C
D D
E E
F F
G G
H H
J J
K K
L L
M M
N N
P P
R R
T T
24
24
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6
5
5
4
4
3
3
2
2
1
1
NOT SPECIFIED
ld-ima30 20190219_asm (2).stp
GEWICHT:
A0
BLATT 1 VON 1 MASSSTAB:1:1
ZEICHNUNGSNR.
BENENNUNG:
ÄNDERUNG
ZEICHNUNG NICHT SKALIEREN
WERKSTOFF:
DATUM
SIGNATUR
NAME
ENTGRATEN
UND SCHARFE
KANTEN
BRECHEN
OBERFLÄCHENGÜTE:
WENN NICHT ANDERS DEFINIERT:
BEMASSUNGEN SIND IN MILLIMETER
OBERFLÄCHENBESCHAFFENHEIT:
TOLERANZEN:
LINEAR:
WINKEL:
QUALITÄT
PRODUKTION
GENEHMIGT
GEPRÜFT
GEZEICHNET
A
C
C
A
DEUTSCHFRANÇAIS
ESPAÑOL ENGLISH
ITALIANO POLSKI
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18
V1
05.06.2019
PRODUCTNAME
A A
B B
C C
D D
E E
F F
G G
H H
J J
K K
L L
M M
N N
P P
R R
T T
24
24
23
23
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21
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20
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10
10
9
9
8
8
7
7
6
6
5
5
4
4
3
3
2
2
1
1
NOT SPECIFIED
ld-ima30 20190219_asm (2).stp
GEWICHT:
A0
BLATT 1 VON 1 MASSSTAB:1:1
ZEICHNUNGSNR.
BENENNUNG:
ÄNDERUNG
ZEICHNUNG NICHT SKALIEREN
WERKSTOFF:
DATUM
SIGNATUR
NAME
ENTGRATEN
UND SCHARFE
KANTEN
BRECHEN
OBERFLÄCHENGÜTE:
WENN NICHT ANDERS DEFINIERT:
BEMASSUNGEN SIND IN MILLIMETER
OBERFLÄCHENBESCHAFFENHEIT:
TOLERANZEN:
LINEAR:
WINKEL:
QUALITÄT
PRODUKTION
GENEHMIGT
GEPRÜFT
GEZEICHNET
D
D
V1
05.06.2019
PRODUCTNAME
A A
B B
C C
D D
E E
F F
G G
H H
J J
K K
L L
M M
N N
P P
R R
T T
24
24
23
23
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10
9
9
8
8
7
7
6
6
5
5
4
4
3
3
2
2
1
1
NOT SPECIFIED
ld-ima30 20190219_asm (2).stp
GEWICHT:
A0
BLATT 1 VON 1 MASSSTAB:1:1
ZEICHNUNGSNR.
BENENNUNG:
ÄNDERUNG
ZEICHNUNG NICHT SKALIEREN
WERKSTOFF:
DATUM
SIGNATUR
NAME
ENTGRATEN
UND SCHARFE
KANTEN
BRECHEN
OBERFLÄCHENGÜTE:
WENN NICHT ANDERS DEFINIERT:
BEMASSUNGEN SIND IN MILLIMETER
OBERFLÄCHENBESCHAFFENHEIT:
TOLERANZEN:
LINEAR:
WINKEL:
QUALITÄT
PRODUKTION
GENEHMIGT
GEPRÜFT
GEZEICHNET
UNDER-TABLE INSTALLATION (rack-mount bracket included in the optionally available rack mount kit
LDIMARK).
Two M4 threaded holes are provided at the top of the corners of the amplifier housing for under-table
installation. Screw the two rack-mount brackets Awith the short sides to the two sides of the housing
using the M4 flathead screws provided (see figure). The amplifier can now be installed in the desired
position under a table.
A
A
ITALIANO
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19
CARE, MAINTENANCE AND REPAIR
To guarantee the flawless operation of the device over a long period, it must be cared for and main-
tained regularly.
CARE (TO BE CARRIED OUT BY THE USER)
WARNING: Before any care measures take place, the power supply and any device
connections must be disconnected.
NOTE! Improper care can damage the device and even destroy it.
1. Housing surfaces must be cleaned with a clean, damp cloth. Make sure that no moisture enters the
device.
2. Air inlets and outlets must be cleared of dust and dirt regularly. If compressed air is used, prevent
any damage to the device (e.g. fans must be blocked in this case).
3. Cables and plug-in contacts must be cleaned regularly and cleared of dust and dirt.
4. Generally, no cleaning agents or agents with a grinding effect should be used as this may cause
damage to surfaces.
5. Devices must generally be stored in a dry place protected from dust and dirt.
MAINTENANCE AND REPAIR (TO BE CARRIED OUT BY SPECIALISTS ONLY)
DANGER! The device contains voltage-carrying components. Even after disconnecting the
power cables, residual voltage may remain in the device, e.g. through charged capacitors
NOTE! There are no user-serviceable parts in the device.
NOTE! Maintenance and repair measures may only be carried out by authorized specialists.
In case of doubt, contact the manufacturer.
NOTE! Improperly performed maintenance work can affect the warranty.
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20
TECHNICAL DATA
Item number LDPREST1
Product type Installation mixer preamplifier
Emergency input 1 balanced line input
Mic/Line inputs 2
Music sources 2 unbalanced stereo line inputs + 1 Bluetooth interface v4.0
Line outputs 2 (Stereo/Mono switchable)
Cooling system Convection cooling
Priority levels 4
Emergency Input
Nominal input sensitivity -3 dBu (Sine 1 kHz, Gain max)
Nominal input clipping 20 dBu (Sine 1kHz)
THD+N < 0.02% (Line OUT, -16 dBu, Gain max, 20 kHz BW)
Frequency response 18 Hz - 20 kHz (Line OUT, -3 dB)
Input Impedance 10 kohms (Balanced)
SNR >100 dB (LINE OUT, -6 dBu, CH Gain set 10 dB, Master Vol min (-inf),
20 kHz BW, a-weighted)
SNR (Best conditions) >105 dB (LINE OUT, +18 dBu, Gain center (0 dB), 22 kHz BW, a-weighted)
CMRR > 48 dB (LINE OUT, -6 dBu 1 kHz)
Gain -40 to 15 dB
VOX Threshold 0%: Off, 25%: -6 dBu, 50%: -27 dBu, 100%: -35 dBu
Priority Contact closure +5VDC Normally Open for dry contact
Connector 5-pin Terminal Block, pitch 5.08mm
Standby wake up threshold -40 dBu
Mic/Line inputs 1-2
Nominal input sensitivity Mic: -26 dBu (Sine 1 kHz, Gain max)
Line: -2 dBu (Sine 1 kHz, Gain max)
Nominal input clipping Mic: -5 dBu (Sine 1kHz)
Line: +19dBu (Sine 1kHz)
THD+N Mic: < 0.02% (LINE OUT, -38 dBu, 20-20 kHz, Gain max, 20 kHz BW)
Line: < 0.01% (LINE OUT, +4 dBu, 20-20 kHz, CH Gain center (0dB), 20 kHz BW)
Frequency response Mic: 165 Hz - 20 kHz (LINE OUT, -3 dB)
Line: 20 Hz - 20 kHz (LINE OUT, -3 dB)
Input Impedance Mic: 1.2 kohms (Balanced)
Line: 10 kohms (Balanced)
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