LD Systems PRE ST 1

Introduction

YOU'VE MADE THE RIGHT CHOICE!

This product has been designed and manufactured to high quality standards to ensure many years of reliable operation. 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 to quickly begin making optimum use of your LD Systems product.

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 professional 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 installations! 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

Please read these instructions carefully. Keep all information and instructions in a safe place. Follow the instructions. Observe all safety warnings. Never remove safety warnings or other information from the equipment. Use the equipment only in the intended manner and for the intended purpose.

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.

During installation, observe the applicable safety regulations for your country.

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 it is cooled sufficiently and cannot overheat.

Never place sources of ignition, e.g., burning candles, on the equipment. Ventilation slits must not be blocked. Keep a minimum distance of 20 cm around and above the device.

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 equipment to flammable materials, fluids or gases. Avoid direct sunlight!

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. Make certain that objects cannot fall into the device.

Use this equipment only with the accessories recommended and intended by the manufacturer. Do not open or modify this equipment.

After connecting the equipment, check all cables in order to prevent damage or accidents, e.g., due to tripping hazards. During transport, make certain that the equipment cannot fall down and possibly cause property damage and personal injuries.

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.

Clean the equipment using a dry cloth. Comply with all applicable disposal laws in your country. During disposal of packaging, please separate plastic and paper/cardboard. Plastic bags must be kept out of reach of children.

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

CAUTION: If the power cord of the device is equipped with an earthing contact, then it must be connected to an outlet with a protective ground. Never deactivate the protective ground of a power cord.

If the equipment has been exposed to strong fluctuations in temperature (for example, after transport), 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.

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.

Do not step on the power cord. Make certain that the power cable does not become kinked, especially at the mains outlet and/or power adapter and the equipment connector.

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.

Whenever possible, avoid switching the equipment on and off in quick succession because otherwise this can shorten the useful life of the equipment.

IMPORTANT INFORMATION: Replace fuses only with fuses of the same type and rating. If a fuse blows repeatedly, please contact an authorised service centre.

Safety Warnings and Symbols

CAUTION: RISK OF ELECTRIC SHOCK DO NOT OPEN: A warning triangle with a lightning bolt symbol, indicating dangerous uninsulated voltage inside the unit, which may cause an electrical shock.

Warning Triangle with Exclamation Mark: Indicates important operating and maintenance instructions.

Hot Surface 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 handling or transporting the device.

Altitude Warning: This device is designed for use below 2000 metres in altitude.

Tropical Climate Warning: This product is not intended for use in tropical climates.

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 producing high sound-pressure levels (SPL) that can lead to irreversible hearing damage in performers, employees, 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 television 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.

Connections, Controls, and Display Elements

The PRE ST 1 is a 4-channel multi-functional stereo mixer preamplifier designed for professional audio installations. It allows users to mix two microphone/line sources with an emergency line input and one of three music sources (including Bluetooth). A four-level priority system, combining contact closure inputs and VOX audio detection, ensures seamless integration.

The unit features two priority contacts: one for the emergency input (muting all other sources) and one for microphone inputs (muting music sources). The stereo balanced line output has a mono/stereo switch and separate bass and treble tone controls. An automatic standby mode is also available to reduce energy consumption.

The intuitive control panel offers easy operation with input and master volume controls, clear signal level and priority indicators, and convenient music source selection and Bluetooth pairing via capacitive buttons. The rear panel is clearly laid out, and the compact 9.5" format facilitates installation.

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

Front Panel Controls and Indicators:

The front panel features input channels with individual controls and indicators, master volume, and status LEDs.

• EMERGENCY Input (4): Features GAIN control, VOX control, and CLIP LED.
• MIC/LINE 1 Input (5): Features GAIN control, VOX control, CLIP LED, and MIC/LINE switch. Also supports chime function via terminal block.
• MIC/LINE 2 Input (6): Features GAIN control, CHIME control, CLIP LED, and MIC/LINE switch.
• MUSIC Input (7): Features MUSIC volume control with SIG and CLIP LEDs. Includes a touch-sensitive button (13) for source selection (Bluetooth, CD/AUX).
• LINE OUT (8): Includes BASS, TREBLE, and ST/MONO controls.
• STANDBY (9): Power switch and standby indicator.
• Volume Controls (10, 11, 12): Individual volume controls for Channel 1, Channel 2, and Music channel, each with SIG (Signal) and CLIP (Clipping) LEDs.
• PRIO LED (16): Indicates active priority mode for MIC/LINE channels.
• EMERG LED (17): Indicates active priority for the EMERGENCY channel.
• STANDBY Button (18): Button to manually engage standby mode.

Rear Panel Connections:

• POWER CONNECTOR (1): IEC socket for power supply.
• FUSE (2): Fuse holder for 250V fuses (5x20mm).
• ON/OFF (3): Rocker switch for power.
• EMERGENCY Terminal Block (4): 5-pole terminal block for emergency input and mute switch connection.
• MIC/LINE 1 Terminal Block (5): 5-pole terminal block for balanced input, plus connection for mute switch. Also features XLR/6.3mm Jack combo socket.
• MIC/LINE 2 Terminal Block (6): Terminal block for balanced input, plus RCA sockets for line input. Also features XLR/6.3mm Jack combo socket.
• LINE OUT (8): Balanced stereo line output via XLR connectors. Includes BASS, TREBLE, and ST/MONO controls.

Priority Levels

The PRE ST 1 features a four-level priority system that mutes lower priority sources when a higher priority signal is detected.

Connection Examples

The following diagrams illustrate typical connection scenarios:

Example 1: System with Players and Call Station

This diagram shows two audio players connected to the MUSIC and MIC/LINE 2 inputs respectively. A call station is connected to the MIC/LINE 1 input. The unit's outputs are connected to active speakers.

Example 2: System with Two Call Stations

This diagram illustrates connecting two call stations to the MIC/LINE 1 input. The mute contacts of both call stations are wired in parallel to the C and + terminals of the MIC/LINE 1 terminal block. This allows either call station to mute music or activate the chime.

Terminal Block Connections

Ensure correct pole assignment when wiring terminal blocks. Incorrect wiring may cause damage.

Emergency Channel Connections:

The EMERGENCY channel uses a 5-pole terminal block for input (+, -, G) and mute switch connection (C, +). An XLR connector is also present.

MIC/LINE 1 Connections:

The MIC/LINE 1 channel features a 5-pole terminal block for balanced input (+, -, G) and mute switch connection (C, +). It also includes an XLR/6.3mm Jack combo socket.

MIC/LINE 2 Connections:

The MIC/LINE 2 channel has a terminal block for balanced input (+, -, G) and RCA sockets for line input. It also includes an XLR/6.3mm Jack combo socket.

Rack Installation

The optional LDIMARK rack installation kit allows for the fixed installation of the PRE ST 1 (or other compatible LD Systems units) in a 19" rack.

The kit includes:

• 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)
• M4 flathead screws and M3 countersunk screws

Single Unit Installation: Attach one short-side bracket (A) and one long-side bracket (B) to the amplifier using M4 screws. The long-side bracket (B) attaches to the opposite side of the amplifier from the short-side bracket (A).

Dual Unit Installation: Use two short-side brackets (A), two small back plates (C), and two bottom plates (D). Connect the units at the back using plates (C) and secure the bottom plates (D) with M3 screws. Attach the short-side brackets (A) to the sides of both units using M4 screws.

Under-Table Installation

The rack-mount brackets (A) included in the LDIMARK kit can also be used for under-table installation. Screw the brackets (A) with their short sides to the top corners of the amplifier housing using the provided M4 flathead screws. The amplifier can then be mounted in the desired position under a table.

Care, Maintenance, and Repair

Regular care and maintenance are essential for long-term flawless operation.

Care (To Be Carried Out by the User)

WARNING: Before any care measures, disconnect the power supply and all device connections.

NOTE! Improper care can damage the device and even destroy it.

• Clean housing surfaces with a clean, damp cloth, ensuring no moisture enters the device.
• Regularly clear air inlets and outlets of dust and dirt. If using compressed air, block fans to prevent damage.
• Regularly clean cables and plug-in contacts.
• Avoid cleaning agents or abrasive agents that could damage surfaces.
• Store devices in a dry place protected from dust and dirt.

Maintenance and Repair (To Be Carried Out by Specialists Only)

DANGER! The device contains live components. Residual voltage may remain even after disconnecting power cables.

NOTE! There are no user-serviceable parts inside the device.

NOTE! Maintenance and repair measures may only be carried out by authorized specialists. Contact the manufacturer if in doubt.

NOTE! Improperly performed maintenance can affect the warranty.

Technical Data

Emergency Input Specifications:

Mic/Line Inputs 1-2 Specifications:

Music Inputs - CD/AUX Specifications:

Music Input - BT Specifications:

Line Output Specifications:

Power Supply Specifications:

General Specifications:

Disposal

Packaging:

1. Packaging can be disposed of via the usual waste disposal channels.
2. Please separate the packaging according to the waste disposal and materials regulations in your country.

Device:

This device is subject to the European Directive on Waste Electrical and Electronic Equipment (WEEE Directive). Old devices and batteries do not belong in household waste. The old device or batteries must be disposed of via an approved waste disposal service or a municipal waste disposal facility. Follow the directives in your country!

Follow the disposal laws in your country.

As a private customer, you can obtain information on environmentally friendly disposal options from the retailer from whom you purchased the product or from the relevant regional authorities.

Manufacturer's Declarations

Manufacturer's Warranty & Limitation of Liability

For current warranty conditions and limitation of liability, visit: https://cdn-shop.adamhall.com/media/pdf/MANUFACTURERS-DECLARATIONS_LD_SYSTEMS.pdf. For servicing, contact Adam Hall GmbH, Adam-Hall-Str. 1, 61267 Neu Anspach / Email Info@adamhall.com / +49 (0)6081 / 9419-0.

CE Conformity

Adam Hall GmbH hereby confirms that this product complies with the following directives (where applicable): Low Voltage Directive (2014/35/EU), EMC Directive (2014/30/EU), RoHS (2011/65/EU), RED (2014/53/EU).

The full CE Declaration of Conformity is available at www.adamhall.com. For further information, contact info@adamhall.com.

EU Declaration of Conformity

Adam Hall GmbH hereby confirms that this type of radio equipment complies with Directive 2014/53/EU. The full text of the EU declaration of conformity is available at: www.adamhall.com/compliance/

Printing errors and mistakes, as well as technical or other changes are reserved!

Front Panel Image Description

The front panel of the LD Systems PRE ST 1 is predominantly black and features a clean, professional layout. From left to right, it includes input channels with associated controls and indicator LEDs, a master volume control, and a standby button. Specifically, there are three input sections labeled EMERGENCY, MIC/LINE 1, and MIC/LINE 2, each with a GAIN control, a VOX control (for EMERGENCY and MIC/LINE 1), and a CLIP LED. The MIC/LINE channels also have a MIC/LINE switch and a PHANTOM ON/OFF switch. The MUSIC channel section has a volume control, SIG and CLIP LEDs, and touch-sensitive buttons for source selection and Bluetooth pairing. The LINE OUT section includes BASS, TREBLE, and ST/MONO controls. A master volume control with a ring-shaped LED display is centrally located. Indicator LEDs for PRIO and EMERG are also present. A power switch is located on the rear panel.

QR Code Description

A QR code is provided that links to the download section for the PRE ST 1 User Manual. The URL is www.ld-systems.com/PREST1-downloads, offering the complete manual in multiple languages including EN, DE, FR, ES, PL, IT, and RUS.

Connection Example Diagram Descriptions

Example 1: System with Players and Call Station

This diagram illustrates a typical setup. Two audio players are connected to the MUSIC and MIC/LINE 2 inputs. A call station is connected to the MIC/LINE 1 input. The unit's LINE OUT outputs are connected to three active speakers, suggesting a multi-zone or multi-speaker setup.

Example 2: System with Two Call Stations

This diagram shows two call stations connected to the MIC/LINE 1 input. The mute contacts of both call stations are wired in parallel to the C and + terminals of the MIC/LINE 1 terminal block. This configuration allows either call station to mute music or activate the chime function.

Terminal Block Connection Diagram Descriptions

Emergency Channel Connections:

The diagram shows the 5-pole terminal block for the EMERGENCY channel, labeled with pins +, -, G for the balanced line input, and C, + for the mute switch connection. An XLR connector is also depicted.

MIC/LINE 1 Connections:

This diagram illustrates the MIC/LINE 1 channel connections. It shows the 5-pole terminal block (+, -, G, C, +) for balanced input and mute switch, alongside an XLR/6.3mm Jack combo socket.

MIC/LINE 2 Connections:

The diagram for MIC/LINE 2 shows the terminal block with pins +, -, G for balanced input, and RCA sockets for line input. An XLR/6.3mm Jack combo socket is also shown.

Rack Installation Diagram Description

Diagrams illustrate the use of the optional LDIMARK rack installation kit. One diagram shows the components: two short-side brackets (A), one long-side bracket (B), two small back plates (C), and two bottom plates (D). Another diagram shows how to attach brackets (A and B) to a single amplifier for rack mounting. A third diagram details the process for installing two amplifiers side-by-side, showing the use of plates (C) to connect units at the back and plates (D) at the bottom, along with the rack-mount brackets (A).

Under-Table Installation Diagram Description

This diagram shows how to attach the rack-mount brackets (A) to the amplifier housing using M4 flathead screws. The brackets are attached to the top corners of the housing, allowing the amplifier to be mounted securely under a table.

Safety Symbols Description

CAUTION: RISK OF ELECTRIC SHOCK DO NOT OPEN: A warning symbol depicting a triangle with a lightning bolt, indicating the presence of dangerous uninsulated voltage inside the unit that could cause an electric shock.

Warning Triangle with Exclamation Mark: A symbol depicting a triangle with an exclamation mark, signifying important operating and maintenance instructions.

Hot Surface Warning: A symbol indicating hot surfaces. Certain parts of the housing can become hot during operation. Allow the device to cool down for at least 10 minutes after use before handling or transporting it.

Altitude Warning: A symbol indicating that the device is designed for use up to a maximum altitude of 2000 meters above sea level.

Tropical Climate Warning: A symbol indicating that this product is not intended for use in tropical climates.

Indoor Use Only: This symbol indicates electrical equipment designed primarily for indoor use.

CAUTION! HIGH VOLUMES IN AUDIO PRODUCTS!: A warning about potential hearing damage from high sound pressure levels (SPL) that can be produced by the device during professional use. It advises avoiding prolonged exposure to volumes exceeding 90 dB.