THEORY DLC-250.4d Amplified Loudspeaker Controller Installation Guide

Technical and Safety Notices

Please read the following important technical, safety and environmental notices before installing and using your amplifier.
Technical Notices 

All reasonable design and engineering steps have been taken to ensure that these amplifiers always perform satisfactorily in their intended application and environment and will provide appropriate levels of support to ensure that all reasonable customer needs and expectations are met. Such support however is contingent on the following provisions.

1. These amplifiers are Class-I products and should be installed with a mains cable including the required earth connection to comply with the Safety Class-I.
2. These amplifiers should always be installed by competent and qualified personnel. Amplifier damage or failure caused by installation or operational errors may invalidate support, warranty or guarantees of performance.
3. These amplifiers are not suitable for use in locations where they may be accessible to minors.
4. These amplifiers are intended to be used specifically for the amplification of audio signals and for connection to moving-coil loudspeaker systems. Use of these amplifiers for amplification of signals outside the audio band (20Hz to 20kHz) or to drive transducers other than moving-coil loudspeakers may invalidate support, warranty or guarantees of performance.
5. These amplifiers should only be used within professionally installed and configured audio systems comprising input and output ancillary equipments that is known to be of an appropriate level of performance and in good operating condition. Any damage to, or unsatisfactory performance from, these amplifiers caused by inadequate or failed input or output ancillaries may invalidate support, warranty or guarantees of performance.
6. These amplifiers are intended to be installed and operated indoor in a controlled environment (pollution degree, PD2) within an ambient temperature range of 0°C to 40°C. These amplifiers are not intended for use above 2000 meters above sea level. Amplifiers installed or operated in environments outside these limits may invalidate support, warranty or 0guarantees of performance.
7. Specific warranty terms are the responsibility of the amplifier re-seller0

Safety and Environmental Notices 

Note: The intent of the lightning flash with arrowhead symbol in a triangle is to alert the user to the presence of uninsulated “dangerous” voltage within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock to humans.

Note: The intent of the exclamation point within an equilateral triangle is to alert the user to the presence of important safety, and operating and maintenance instructions in this manual.
WARNING! TO PREVENT FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.
Ambient Temperature Note: If this equipment is operated in a confined or multiple rack installation, the internal ambient operating temperature may exceed the external ambient temperature. It is important to ensure in these circumstances that the published maximum operating temperature for the equipment is not exceeded.

1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Do not submerge the equipment in water or liquids.
7. Do not use any aerosol spray, cleaner, disinfectant or fumigant on, near or into the equipment.
8. Clean only with a dry cloth.
9. Do not block any ventilation opening. Install in accordance with the manufacturer’s instructions.
10. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
11. To reduce the risk of electrical shock, the power cord shall be connected to a mains socket outlet with a protective earthing connection.
12. Do not defeat the safety purpose of the polarized or grounding type plug. A polarized plug has two blades with one wider than the other.
    A grounding type plug has two blades and a third grounding prong.
    The wide blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet.
13. Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
14. Do not unplug the unit by pulling on the cord, use the plug.
15. Only use attachments/accessories specified by the manufacturer.
16. Unplug this apparatus during lightning storms or when unused for long periods of time.
17. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.
18. The appliance coupler, or the AC mains plug, is the AC mains disconnect device and shall remain readily accessible after installation.
19. Adhere to all applicable, local codes.
20. Consult a licensed, professional engineer when any doubt or questions arise regarding a physical equipment installation.

Introduction and Overview

Introduction

THEORY DLC power amplifiers have been designed to provide configurable, consistent and reliable high performance audio power amplification for residential, commercial and entertainment applications. Please read this manual fully before installing and using an amplifier. If you have any questions regarding amplifier configuration, installation or operation please contact the appropriate customer support portal.
Following this introduction, the manual is divided into sections covering the following topics:

• 2. Overview
• 3. Carton Contents
• 4. Installation
• 5. Configuration
• 6. Connections
• 7. Operation
• 8. Specifications

Firmware
This manual describes the features, functions and user interface of THEORY DLC amplifiers running Firmware Version 1.7.3.
It is strongly recommended that the firmware version installed in the amplifier in use is checked initially, and regularly thereafter. If updated firmware is available, the amplifier should be updated as a priority.
The firmware installed in the amplifier can be identified and updated by selecting the Device option in the Control web app Settings Menu.
Firmware versions can be checked, and firmware downloaded, from the THEORY DLC website: www.theoryaudiodesign.com.

Carton Contents
THEORY DLC amplifiers are shipped in a cardboard carton containing the amplifier unit, a mains cable appropriate for the sales territory, an accessory pack, and a document pack. The full contents is listed below.

• Amplifier unit
• Mains power cable
• Input connector x 2
• GPIO socket connector
• Output connector x 2
• Adhesive rubber feet x 4
• Document pack
• Rack Kit

Overview

Diagram 2
THEORY DLC four channel amplifier dimensions.
(Shaded area defines ventilation space.)

Diagram 4a
THEORY DLC
Rack Ear + Half-rack Extension.

Diagram 4b
THEORY DLC
Rack Support hardware. 2 positions.

Installation

Installation
Note: The desk/wall mounting components described and illustrated in Sections 4.2 to 4.3 and rear support hardware in Section 4.1 are not supplied with THEORY DLC amplifiers but are available to purchase as an accessory.
Contact your amplifier re-seller for more information.

THEORY DLC Mounting
The THEORY DLC amplifiers are shipped without rack mount hardware attached but can be configured for rack installation using the included one standard rack ‘ear’ and one half-rack extension piece as illustrated in Diagram 4a. The installation and equipment rack should be configured to provide appropriate ventilation airflow space around the sides and rear of the amplifier as illustrated in as illustrated in Diagram 2. Ventilation airflow space of at least 25 mm (1 in) should be maintained along at least one side of the amplifier at all times.

Ventilation apertures are also located on the rear panel of the amplifier and must not be obstructed. It is important to retain at least 80 mm (3.1 in) free space for airflow behind the amplifier rear panel. In addition to rack mount ears, optional rack mount rear support hardware is available and can be attached to the amplifier. Rear support hardware may be appropriate if the amplifier is to be used in a mobile rack or potentially be subject to significant movement. Diagram 4b illustrates the use of rack mount rear support hardware.
Multiple THEORY DLC amplifiers can also be mechanically connected using the bushing hardware illustrated in Diagram 4c and connecting plates illustrated in Diagram 4d.

Diagram 4d
2 x THEORY DLC with Connection Plate. 2 positions

Diagram 4c
Bushing hardware to connect 2x THEORY DLC

Configuration

Free-standing

If not installed in an equipment rack, THEORY DLC amplifiers can be placed free-standing on a flat surface. Adhesive rubber feet are supplied for this purpose.
THEORY DLC amplifiers can also be attached to the underside of desks or wall mounted using connecting plate hardware (optional accessory, not included). The adhesive rubber feet should also be used in these circumstances to minimise the possibility of vibration between the amplifier and mounting surface. Wall and desk mounting is illustrated in Diagrams 4e and 4f

Diagram 4e
THEORY DLC
with desk/wall Mounting Plate and adhesive feet. 2 positions and 4 positions.

It is important in any free standing installation that airflow through the amplifier’s side panel mounted fans and rear panel ventilation apertures is not compromised by adjacent items. At least 80mm (X in) of free space behind the amplifier and 25mm along at least one side should be retained at all times.

Configuration
Before making input, output and GPIO connections, an initial THEORY DLC amplifier configuration should be established. It is particularly important that the amplifier output format is configured appropriately for the speakers that are to be connected.
Configuration requires that THEORY DLC amplifiers are connected to mains power and network services. These connections are described in the following two sections.

Mains Power Connection
THEORY DLC amplifiers incorporate a power factor corrected power supply and can be used with mains input voltage from 100V AC to 240V AC, 50/60Hz. Use the mains cable supplied with the amplifier and connect it to a mains supply.
THEORY DLC amplifiers have no mains power switch and are operational as soon as mains power is connected.

Network Services
THEORY DLC amplifiers are configured via a web page interface called THEORY DLC Control. Before the configuration menus can be accessed, THEORY DLC amplifiers must be connected to the same TCP/IP network as the computer or mobile device that is to be used for configuration access.

Wired (Ethernet) Network Connection
To connect a THEORY DLC amplifier to a TCP/IP network using a wired connection (Ethernet) follow the steps below.

1. Use an Ethernet cable to connect the THEORY DLC amplifier rear panel Network Control socket to a free socket on a network router or switch, or directly to an Ethernet equipped laptop or desktop computer.
2. Connect the THEORY DLC amplifier to mains power using the supplied mains cable. Wait for the front panel Network indicator to illuminate blue to indicate that the amplifier has network connectivity.
3. THEORY DLC amplifiers are configured to use DHCP for network connection. A network scanning app can be used to identify the IP address.
   DHCP and Fixed IP address option settings can be found in the Settings Tab menu described in Section 5.3.5.

Wireless (WiFi) Network Connection
To connect a THEORY DLC amplifier to a TCP/IP network using a wireless connection (WiFi) follow the steps below.

1. With the THEORY DLC amplifier connected to mains power, wait for the front panel WiFi indicator to illuminate blue.
2. Use a mobile, laptop or desktop device to search for available WiFi networks. Connect to, THEORY DLC (product serial number)’ using the password, ‘password’. The amplifier serial number can be found on its rear panel.
3. Open a computer or mobile device web browser and enter the IP address: 192.168.4.1. The THEORY DLC Control Web App interface will open to enable amplifier configuration as required.
4. Select the Web App Settings Tab followed by WiFi > WiFi Mode > Client to configure the amplifier to connect to the required WiFi network. The WiFi network name and password will be required.
   It is strongly recommended that the THEORY DLC amplifier Access Point WiFi password is changed following initial wireless connection.

Configuration Menus
Opening a web browser that is network connected to a THEORY DLC amplifier initially displays the THEORY DLC Control Web App Dashboard illustrated in Diagram 5a. The Dashboard is the ‘home’ page from which all other configuration options can be accessed.
The Dashboard displays the amplifier status, output zones and the configuration menu tabs. It also enables immediate access to zone volume control The functions available under each configuration menu tab are described in the following sections.

Input Tab
The Input Tab provides naming, mono/stereo selection, sensitivity, and gain trim for each amplifier input channel. An internal pink noise source, provided for system testing and set up, can also be enabled or disabled, and adjusted for gain via the Input Tab. Diagram 5b, 5c, 5d and 5E illustrates the Input Tab. Dante Input Tab, Input EQ and Input Mix displays respectively.
Note: The inputs displayed in the Dante® input tab will correspond to those configured and enabled in the Dante® Controller Mac OS or Windows application. If no inputs are displayed they must first be enabled in Dante® Controller.

Diagram 5a
Configuration Dashboard display

Diagram 5b
Input Tab display (two inputs only shown)

Note: When adjusting input gain, the input level display should remain orange. If it displays red, the input gain should be reduced.

Diagram 5c
Input EQ display

Diagram 5d
Dante® Input display

Zone Tab
The Zone Tab enables installation zones to be defined and named, and provides access to further sub-menus. Zones might be bar or restaurant areas for example, or different rooms in a home. For all Zone Tab menus, the installation zone under configuration is selected by highlighting one of the zone identifiers (A, B, C or D) at the top of the page. Diagram 5f and 5g illustrates the Zone Tab and Source menu displays.

• The Source menu option enables inputs to be assigned to zones and
  Input Priority or Input Ducking to be configured. The Input Priority function enables an alternative input to replace and mute the input primarily routed to the zone under configuration when the alternative input exceeds a preset level.
• The Input Ducking function enables an alternative input to replace and attenuate the input primarily routed to the zone under configuration when the alternative input exceeds a preset level.

Note: Input Priority and Input Ducking parameters can be either set to default values or their Threshold, Attack, Hold and Release values set as required. Input Priority can also be set to ignore the volume level set for the specified zone and take a specific override volume.

• The Volume menu allows minimum and maximum zone volume limits to be set, and enables external GPIO volume control to be applied to individual zones. The GPIO configuration menu can be found under the Settings Tab, and notes on connecting an external volume control via the GPIO interface can be found in Section 5.5 of this manual.

Diagram 5e
Input Mix display

Diagram 5f
Zone Tab display

Diagram 5f
Zone Tab display

Note: If an amplifier is controlled via a third-party control system API, volume level limits set via the Input Tab will not apply.

• The Restrictions menu enables zone inputs or input mixes to be restricted from routing to particular zones.
  Note: Routing restrictions cannot be applied to priority zone inputs.
  Note: If an amplifier is controlled via a third-party control system API, input routing restrictions set via the Input Tab will not apply.
• The Compressor option enables default or custom signal compression to be applied to individual zones.

Output Tab
The Output Tab enables amplifier outputs to be named, linked to zones, and provides access to Delay, Room Equalizer and Speaker Preset menus. Diagram 5h illustrates the Output Tab display.
For all Output Tab menus, the amplifier output under configuration is selected by highlighting one of the output identifiers at the top of the display.
Note: The number of individual outputs available for configuration will depend on the THEORY DLC amplifier model and the input, zone and output mode configuration. The diagrams following illustrate a four output amplifier.

• The Routing menu enables zones to be assigned to amplifier outputs.

Note: Routing for zones specified as stereo will automatically offer three output options: left channel, right channel or summed mono.
The summed mono signal can potentially be used to drive a mono subwoofer or a 70/100V mono speaker line.

Diagram 5h
Output Tab display

Diagram 5i
Speaker Preset Parameters

• The Delay menu enables delay to be applied to individual amplifier outputs.
• The Equalizer menu enables parametric equalization to be applied to individual amplifier outputs. Equalizer settings configured for one amplifier output can be copied and applied to other outputs.
• The Speaker Preset menu enables a set of speaker parameters to be adjusted, and preset configurations to be created, exported, imported or cleared.

Speaker Presets can be simply applied to the selected amplifier output or imported, chosen from a library, exported or cleared. Diagrams 5i to 5l illustrate the application of speaker presets.

Speaker Preset data provided by THEORY or PRO AUDIO TECHNOLOGY for use with their speakers can be imported and applied to amplifier outputs. To import speaker preset parameters follow the steps described below and illustrated in the diagrams

1. Select either the FROM LIBRARY or IMPORT FILE option from the Speaker Preset menu. If no import option is visible, select CLEAR to delete any existing speaker preset data.
2. If selecting the IMPORT FILE option, browse your device for the appropriate ‘.zcp’ format speaker preset data file. If selecting the FROM LIBRARY option, select the appropriate speaker model from the library. The preset data will be applied to the selected amplifier output as soon as the file import is complete.

Diagram 5k
Speaker Preset applied

• The System Information menu provides text fields for the recording of installation data.
• The Device menu records amplifier specific information such as the model number and firmware version. A firmware update routine and identifier button can also be found under the Device menu.
• The External Devices menu enables a DLC-CTRL wall mount control to be paired with an amplifier and configured. Each individual amplifier zone to be controlled will require its own control device. Diagram 5n illustrates the External Devices display.
• Name zones by typing in the Zone Name field.
• Adjust the zone volume if required by using the slider.
• Define a mono or stereo zone by selecting the appropriate option.
  Defining a stereo zone will reduce the total number of further zones available.
• Specify an input for the zone by selecting from the drop-down menu.
  Selecting a stereo input for a mono zone will automatically sum the stereo channels to mono.

Note: When configured in Hi-Z mode DLC-250.4d amplifiers operate in ‘bridged’ format where the output of two channels is combined. This means that the number of output channels available in Hi-Z mode is half that available in Lo-Z mode.

Note: Mono signals might be mono at source, created though combining the left and right channels of a stereo signal (summed mono) or treating the left and right channels of a stereo signal independently (split mono).

• Name zones by typing in the Zone Name field.
• Adjust the zone volume if required by using the slider.
• Define a mono or stereo input by selecting the appropriate option.
  Defining a stereo input will reduce the total number of discrete inputs available.
• Specify an input for the zone by selecting from the drop-down menu. Selecting a stereo input for a mono zone will automatically sum the stereo channels to mono.
• The Backup & Restore menu enables amplifier configuration data to be downloaded to an external archive, and enables previously saved configuration files to be uploaded and adopted by the currently connected amplifier.
• The Speaker Library menu enables management of speaker preset libraries. Existing libraries of speaker preset files (.zcl) can be created or imported, and existing libraries edited or fully deleted. Diagram 6o illustrates the creation and management of speaker preset libraries.
• The Security menu enables a password to be set in order to protect against unauthorised access to the amplifier Control Web App.

Password protection is particularly important when an amplifier is connected to a wired network as the a WiFi password is no longer required to gain access to Control Web App

Diagram 5l
Speaker Preset parameter adjustment

Note: It is recommended that a Control Web App password is different from that required to gain access to the amplifier via WiFi.

• The Power Management menu enables various automatic switch-on options to be engaged. The Power Management menu also offers timed Standby and Mute functions.

Note: In Eco mode the network is switched off during standby. When the amplifier has Dante® enabled, use the Audio (Digital) or Network Only settings.

• The Output Routing menu enables specified inputs or zones to be routed to the amplifier S/PDIF outputs. The output level can also be adjusted.

Any zone or input can be routed to either digital output, including inputs not actively assigned to a zone. Primary or priority input status is immaterial. The specified input is always routed to the specified output to be available for use by downstream devices.

Note: When a zone is selected for the digital S/PDIF (or Dante®) output – the output signal is variable. However, when an input signal is routed out an S/ PDIF (or Dante®) output, the signal will be fixed.

Note: The digital output function is especially useful when amplifiers are to be daisy chained and a specific input; a central paging mic, for example, is required to be routed to multiple amplifiers.

• The Dante® menu enables identification of Dante® capable devices present on the AoIP network. Dante® devices must be appropriately enabled and configured using Dante® Controller. Use Dante® Controller to activate AES67 mode if required.
• The GPIO menu enables configuration of the multi-purpose GPIO interface pins. A description of the individual settings is detailed in THEORY DLC Control.
• The LAN menu enables configuration and reset of the wired network options and parameters.
• The WiFi menu enables configuration and reset of the wireless network options and parameters.

Diagram 5m
Settings Tab menu

Input Setup
Open the configuration Dashboard and select the Input Tab. The Input Tab is shown in Diagram 5b.

• To edit default input names simply select and type in the Input Name field.
• Define a mono or stereo input by selecting the appropriate option.
  Defining a stereo input will reduce the total number of discrete inputs available.
• Select an input sensitivity option from the drop-down menu: +14dB, +4dB, -10dB and ‘microphone’ options are available. Generally, the +14dB or +4dB options are appropriate for ‘professional audio’ source hardware with balanced outputs, while the -10dB option is more appropriate for ‘consumer audio’ source hardware with unbalanced outputs. The ‘microphone’ option provides the significantly greater sensitivity required for microphones.

Note: Only dynamic microphones are suitable for connection. Phantom power for condenser microphones is not provided.

• If necessary, adjust the input gain using the slider or up/down icons.
  Gain adjustment is intended to be used for fine output level adjustment following initial use. If necessary, adjust the input EQ using the 5 band equalizer

Diagram 5o
Speaker Library Creation and Management

Zone Setup & Routing
Open the configuration Dashboard and select the Zone Tab. The Zone Tabis shown in Diagram 5f.

• Select the zone to be configured. The number of zones available and their channel format (stereo or mono) will depend on the amplifier model, input setup and output mode (Lo-Z or Hi-Z). For example:
• A four output amplifier can have the following zones configured:
• 2 x stereo Lo-Z zones
• 4 x mono Lo-Z zones
• 2 x mono Hi-Z
• 1 x mono Hi-Z + 1 x stereo Lo-Z zone
• 1 x mono Hi-Z + 2 x mono Lo-Z zones

Diagram 5p
Signal Flow Schematic

GPIO Setup and Connection
THEORY DLC amplifiers provide a GPIO socket that enables remote control of volume, standby, mute and trigger functions.
The GPIO connector pin functions are described in the GPIO Settings menu illustrated in Diagram 5q. The connection of GPIO based remote volume control and standby/mute are illustrated in Diagram 5r and Diagram 5s respectively.
Note: The GPIO connector must not be used for any unintended purpose. Amplifier damage may result from incorrect use of GPIO.
Note: Shielded cable must be used when connecting standby switches and potentiometers via GPIO.
Note: GPIO Pin 8 has a low output impedance and is able to supply a maximum current of 10mA.
Note: GPIO Pin 1 and Pin 3 both offer ground connections: Pin 1 is connected directly to the amplifier chassis.
Pin 3 is connected to the chassis via a 220 Ohm resistor. The ‘soft ground’ connection of Pin 3 is potentially useful for managing ground loops that may cause audible hum.

Diagram 5q
GPIO Settings Menu

Diagram 5r
Potentiometer connections for remote volume control via GPIO.
Note: Diagram 6d illustrates use of the GPIO connector.

Switch open or closed toggles Standby or Mute depending on options selected in the GPIO Settings Menu

Connections

Connections

THEORY DLC amplifier rear panel connections are illustrated in Diagram 6a.

Mains Power Connection
THEORY DLC amplifiers incorporate a power factor corrected universal power supply and can be used with mains input voltage from 100V AC to 240V AC, 50/60Hz. Use the mains cable supplied with the amplifier.
THEORY DLC amplifiers have no mains power switch and are operational as soon as mains power is connected. Ensure that all signal, GPIO and output connections are made before connecting the amplifier to mains power.

Input Connection
All THEORY DLC amplifier models provide four balanced or unbalanced analog audio inputs and a stereo S/PDIF digital audio input. Any input channel can be routed to any output channel. Input routing options can be configured via the amplifier network interface. See Section 5 of this manual.

Analog Inputs
THEORY DLC analog inputs are of line level format with a default input sensitivity of +4dBu (full output voltage swing/sensitivity) in all output modes. Input signal levels up to +24dBu can be handled without input clipping. Input sensitivity options can be set via the amplifier network interface.
See Section 5 of this manual.

Balanced input connections to the amplifiers are made via male ‘Euro Block connectors. Connecting cables to the supplied female input connectors is illustrated in Diagram 6b.
Unbalanced input connections to the amplifiers are made via RCA phono sockets connected in parallel with the balanced inputs.

Diagram 6a
THEORY DLC rear panel connections.

In the case of Lo-Z speaker connections, positive (+) amplifier terminals should always be connected to positive speaker terminals and negative (–) amplifier terminals always connected to negative speaker terminals.

Note: Cable lengths should not exceed 250m.

Diagram 6b
Balanced analog input cable connections

Diagram 6d
GPIO cable connections

Diagram 6c
Output cable connections.

The exclamation point printed next to the output terminals of the amplifiers is, in addition to the CLASS 2 WIRING text, intended to alert users to the risk of hazardous voltages. Output connectors that could pose a risk are marked with the exclamation point. Do not touch the output terminals while the amplifier is switched on. Make all connections with the amplifier switched off.

Operation

Once all connections have been made and configuration options selected, THEORY DLC amplifiers are ready for use. If an input signal above -60dB is present on any input, the front panel Input and Standby indicators will illuminate blue to indicate normal amplifier operation. Audio will be heard from any connected speakers.

Note: THEORY DLC amplifiers will not switch on from Standby Mode unless an input signal is present, a network ‘ON’ command is received, or an external standby switch (or 12V trigger) is operated. Standby behaviour can be configured via the Power Management menu of the Settings Tab.

Amplifier outputs will mute if no input signal is present for 5 minutes, and the amplifier will switch automatically to Standby Mode if no signal is present on any input for more than 15 minutes. Alternative standby and mute delay times can selected via the Settings Tab. Amplifier cooling fan speed is temperature controlled. The fan will switch off when the amplifier enters standby mode.

Front Panel Indicators 

THEORY DLC amplifier front panel indicators illuminate to indicate the following operational states:

Automatic Power Sharing
THEORY DLC amplifiers incorporate a power sharing feature that automatically shares the total power available from the amplifier’s internal power supply across each pair of output channels. If one channel temporarily demands more than the amplifier’s continuous power rating while other channel is demanding less, the excess power available from the internal power supply is automatically made available to the over-power channel.
Power sharing optimises the amplifier’s ability to deliver maximum power into dynamic loudspeaker loads when playing music programme material.

Default Reset
THEORY DLC amplifiers can be returned to their default settings via either the Control Web App Settings Tab or the hardware reset pinhole button. The reset pinhole button is located on the underside panel of the amplifier.
To reset the amplifier using the pinhole button, follow the steps below:

• Disconnect the amplifier from mains power.
• Use an appropriate tool to press and hold the reset pinhole button while simultaneously reconnecting mains power.
• Continue to hold the reset pinhole button for a few seconds as the amplifier restarts.

The amplifier will restart with all settings at their default state.
Any previously configured settings will be deleted.

Specifications

*100V line mode is @ -1dB (≈ 90 V)
**DLC-250.4d may only Powershare across Ch1/2 and Ch3/4

Power Efficiency Data
The following table describes the efficiency and power performance of THEORY DLC amplifiers.
The table also includes the derived thermal losses.

*As per compliance to ErP

Propagation Delay Data 

The following table describes the input/output latency performance of THEORY DLC amplifiers.

*Dante® network latency not included.

Note: Dante® latency is measured in a Dante® to Dante® connection setup. The propagation delay is both measured from both analog inputs and digital inputs. The total delay of: Amp1 SPDIF input to Dante® out -> Amp2 Dante® input to SPDIF output is 4333µs. Out of this the network latency accounts for 1000µs and the ASCRs accounts for 3 x 1000µs. Out of the final 333µs seconds, the DSP accounts for roughly 208µs, leaving 125µs for the Dante® chip processing. For this test the Dante® process occurs twice resulting in a 62,49µs delay per Dante® transmission.

Documents / Resources

THEORY DLC-250.4d Amplified Loudspeaker Controller [pdf] Installation Guide DLC-250.4d Amplified Loudspeaker Controller, DLC-250.4d, Amplified Loudspeaker Controller, Loudspeaker Controller, Controller

References

• User Manual