CasaTunes CT-250A, CT-2100A and CT-2150A Amplifiers


The CasaTunes CT-250A, CT-2100A and CT-2150A amplifiers are 2-channel class D power amplifiers that offer 2 x 50W/channel, 2 x 100W/channel and 2 x 150W/channel, respectively. They are a perfect choice to use with the pre-amp only outputs, Zones 7 & 8, on the CasaTunes CT-12X8 Matrix Amplifier.

These amplifiers are rack mountable. You can mount these in the rack as a single unit, or a dual unit, side-by-side without requiring any additional rack space. The rack mount hardware for both configurations is included.

These energy friendly amplifiers use less than 0.5W in standby mode, and can be switched in & out of standby with a 12V input trigger. You can connect the 12V output triggers on Zone 7 & 8 on the CasaTunes CT-12X8MA to control the amplifier.

Important Safety Instructions

  1. Read these instructions.
  2. Keep these instructions.
  3. Follow all instructions.
  4. Do not use this apparatus near water.
  5. Clean only with dry cloth.
  6. Do not block any ventilation openings.
  7. Install in accordance with the manufacturer’s instructions.
  8. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus(including other amplifiers) that produce heat.
  9. Use the apparatus only inModerate climates (not in tropical climates).
  10. 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 grounding prong are provided for your safety. If the provided plug does not fit onto your outlet, consult an electrician for replacement of the obsolete outlet.
  11. Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
  12. Only use attachments and accessories specified by the manufacturer.
  13. Unplug this apparatus during lightning storms or when unused for long periods of time.
  1. If you install the apparatus in a built-in installation, such as a bookcase or rack, ensure that there is adequate ventilation. Leave 20cm (8”) of free space at the top and sides and10cm (4”) at the rear. The rear edge of the shelf or board above the apparatus shall be set 10cm (4”) away from the rear panel or wall, creating a flue like gap for warm air to escape. Good airflow is necessary to help ensure proper operation. Not only should you provide enough free space around the unit, but also ensure that air can flow freely and escape from the amplifier surroundings. Failure to do so may cause thermal shutdown of the unit, and reduced life expectancy.


Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as:

  • When the power supply cord or plug is damaged
  • If liquid has been spilled, or objects have fallen into the apparatus.
  • If the apparatus has been exposed to rain or water.
  • If the apparatus has been dropped or damaged in any way.
  • If the apparatus does not operate normally by following the instructions. Adjust only those controls that are covered by the operating instructions.
  • When the apparatus exhibits distinct change in performance this indicates a need fora service.

WARNING! Do not expose the apparatus to dripping or splashing.Do not place objects filled with liquids near the apparatus.

WARNING! To reduce the risk of fire orelectric shock, Do notexpose this apparatus to rain or moisture.

WARNING! Equipment must be connected to a Mains socket outlet with a protective earthing connection.

WARNING! Never push objects of any kind into the apparatus through openings as they may touch dangerous voltage points or short-out parts that could result in a fire or electric shock.

IMPORTANT! Ensure adequate ventilation. Do not install in a cabinet that is smaller than 60cm (24”) wide x 45cm (18”) deep x 20cm (8”) high. If you do the device may overheat.


AC Fuse

The AC fuse inside the unit is not user-serviceable. If you cannot turn on the unit, contact the dealer from whom you purchased this unit.


Occasionally you should dust the unit all over with a soft cloth. For stubborn stains, use a soft cloth dampened with a weak solution of mild detergent and water. Dry the unit immediately afterwards with a clean cloth. Don’t use abrasive cloths, thinners, alcohol, or other chemical solvents, because they may damage the finish or remove the panel lettering.



AC outlet voltages vary from country to country. Make sure that the voltage in your area meets the voltage requirements printed on the unit’s rear panel. e.g. ~ 110V / 240V, 50/60HZ The power cord is used to disconnect this unit from the AC power source. Make sure that the plug is readily operable (easily accessible) at all times.

If you do not intend to use the unit for an extended period, remove the power cord from the AC outlet.


The unit is defined as Class1 in EN60065 (low voltage directive) and MUST BE EARTHED. Connect only to a mains socket outlet with protective earth, and only use the power cord supplied.

  1. Finland: – Laite on Liitettävä suojamaadoituskoskettimilly varustettun pistorasiaan
  2. Norway – Apparatet må tilkoples jordet stikkontakt
  3. HandlingNotes - Apparaten skallanslutas till jordat uttag

Never Touch This Unit with Wet Hands

Never handle this unit or its power cord while your hands are wet or damp. If water or any other liquid gets inside this unit, have it checked by your CasaTunes dealer

Handling Notes

The AC fuse inside the unit is not user-serviceable. If you cannot turn on the unit, contact the dealer from whom you purchased this unit.

  1. If you need to transport this unit, use the original packaging
  2. Do not leave rubber or plastic items on this unit for a long time; they may leave marks on the case.
  3. This unit’s top and rear panels may get warm after prolonged use. This is normal.

Speaker Shorts

Under no circumstances should the speaker output terminals of the unit be short circuited, grounded or connected to another output.

Direct Sunlight

Avoid installing the amplifier in positions where the front panel is exposed to direct sunlight – may cause control to become sluggish.

Controller Connection

Never connect more than eight CasaTunes controllers. The supply is internally fused (self resetting) and may open circuit. Never connect the unit’s 12VDC terminal (‘BusRun’ port) to an external power supply.

Declaration of Conformity

We declare under our sole responsibility that this product, to which this declaration relates, is in conformity with the following standards:

Following the provisions of Low Voltage Directive 2006/95/EC and EMC Directive2004/108/EC, the EC regulation 1275/2008 and its frame work Directive2009/125/EC for Energy-related Products (ErP).

TUV Certification

This product has been certified and conforms to UL60065 and certified toCAN/SSA, IEC 60065

For North American Models

FCC interference statement
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. certified and conforms to UL60065 and certified toCAN/SSA, IEC 60065

IMPORTANT! Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.

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 of the following measures:

For Canadian Models


For models having a power cord with a polarized plug:

Modèle pour les Candadien


Sur les modèles don’t la fiche est polarisée:




The amplifier has six separate amplified zones and two pre-amplified zones. Each zone has controls for bass, treble, balance, loudness, gain, mono and maximum volume limiting.

The two pre-amplified zones include a low pass filter that when selected only passes low frequency audio, ideal for driving Active Subwoofers. When the low pass filter is selected the tone and loudness settings are defeated.

Each zone maybe set to a specific volume level when powered on.


You can have up to 96 zones by adding more CT-12X8 matrix amplifiers.

To share the same sources between units you can daisy chain the sources by connecting the Digital Coax Outputs for Sources 1-12 on one unit to the Digital Coax Inputs on the next unit, and repeat for each additional unit.


The amplifier has twelve separate sources.

Sources 1-8 are either Analog Stereo, or Coax Digital Audio (PCM). Digital Coax has priority if both are connected.

Sources 9-12 are either Coax or Optical Digital Audio (PCM). Only one connection  to each source is allowed.

You can adjust the gain on each Analog Source, up to +10dB in 2dB steps.

Sources 1 -12 support a programmable delay of up to 600ms in 5ms steps


Up to10 seconds of 44.1 KHz 16 bit stereo sounds may be generated as part of a page preset. Suitable wav files are uploaded to the unit using the ADP program.

Here's a thought!
If you are using a CasaTunes Music Server, you can configure custom doorbell chimes and flexible room configurations

Power Failure Restoration

After an AC power outage the amplifier restores its settings to the pre-interrupted state. All internal settings are stored in non-volatile memory.

Restore Defaults

The  amplifier may be readily set to the default settings. Restoring Defaults clears all memory and resets the zone allocations to zones 1 – 8

Firmware Upgradeable

The amplifier may be updated with the latest operational firmware by either Internet download or by using rear panel USB and ADP program.

Thermal Control

The amplifier automatically monitors the temperature and takes progressive action depending on the temperature.

When the temperature reaches:

  • 194°F (90°C) the amplifier volume is reduced 20dB
  • 212°F (100°C) the amplifiers are shut down until the temperature drops below 194°F (90°C)

Amplifier ON Status (Amp-On)

There are 8 outputs, one for each zone, on the rear panel of the amplifier labeled AMP ON Control 1, 2, 3, 4, 5, 6, 7, 8. When a  zone is powered, the associated output is switched to 12V DC. This can be used to control a secondary amplifier and switch it in & out of standby mode.

Zone Linking

A zone may be linked to multiple zones. Zone linking ties the source selection together, and optionally the volume and standby. This is useful for closely coupled audio areas where it is advantageous to have different volume control but the same source, or the same volume with separate standby control. Zone linking is setup either via the front panel user interface or Web application

Here's a thought!
If you are using a CasaTunes Music Server, use Room Groups which behave similar to Zone Linking but offer even more flexibility

IP Control

The amplifier is controlled, monitored and programmed via Ethernet. In most instances, the CasaTunes music server will be used to control the amplifier.


The amplifier has 10 buffered IR emitters. Ports 1-8 have IR routing, and are intended to control specific input source components. Two IR ports 9 & 10 are the sum of all IR sources; these control All the zone source components.

Presets and Paging

There are 14 amplifier presets and two page presets.

Presets 1 - 14 are momentary and cause the amplifier to go to a predetermined state, i.e. standby, volume & source selection.

The Page Preset mode is for paging applications and is invoked by a contact closure between the 0V and PG1 or PG2 terminals. The contact closure must have an external power source i.e. a 12 – 24V AC/DC powered door bell. When the contact closure is released (power sensed across PG – 0V terminals) the amplifier zones return to their previous states. PG1 is always assigned to the Page Preset. PG2 may be assigned to any one of the 15 available Presets.

Use the amplifier Web application to configure the presets.

Front Panel

1 - Front Panel

Solid Aluminium front Panel

2 - Infrared Receiver

Receiver for front panel IR control – Used only for amplifier control, not IR passthrough

3 - Power Indicator

The power indicator glows blue whenever AC power is applied

4 - 2.4” Color LCD Touch Panel display

LCD Touch Panel display for menu guided control and programming. The display is dimmed to “Off” after 15 minutes of inactivity

5 - Chassis Feet

Set high enough to provide unrestricted airflow through the chassis for convection cooling

Back Panel

1 - AC Inlet

IEC socket

2 - Speaker Terminals

Plug in terminal clamp connectors accept 1.5mm² speaker wires

3 - Coax Digital Source Input Terminals

Coax digital inputs

4 - Coax Digital Source Output Terminals

Coax digital outputs for expansion to further amplifiers

5 - Ethernet Port - MAIN IN

MAIN IN is 10/100 Base T primary Ethernet port for connection to the Home network Router or switch

6 - Ethernet Port - EXT OUT

EXT OUT is 10/100 Base T secondary port for connection to another amplifier MAIN IN Ethernet Port

7 - Zone Preamplifier Outputs

Zone 7 & Zone 8 analog audio L/R outputs

8 - Analog Input Source Terminals

Source S1 – S8 analog audio L/R inputs

9 - IR Emitter Ports

3.5 mm mono jacks. IR1 thru IR8 are used to control specific source equipment, where each IR port may be assigned to a specific keypad(s). IR9 & IR10 are used to control source equipment common to all zones. These ports output the combined IR1 – IR8 infrared signals

10 - Optical Digital Source Inputs

Optical digital source inputs

11 - Keypad Ports

For connection to keypads

12 - AMP ON Control

AMPON 1 thru 8 outputs are set to 12VDC when zone is on

13 - PRESETS - Door Bell

12– 24V AC/DC powered doorbell trigger terminals

Typical System Configuration

Figure 1 - Typical System Configuration

Figure 1 depicts a typical configuration where the amplifier is providing audio into six of the possible eight listening zones. Only three of the Zones are depicted. Each zone consists of a room with a pair of speakers and a suitable controller. Each zone may be listening to any of the connected sources: CasaTunes music server, Amazon Echo Link, TV, etc


Each zone has a specific control requirement. Choose the controllers that best suit the application.

  • Zone1 – The Living Room: Keypad with IR receiver
  • Zone2 – The Kitchen: Phone
  • Zone3 – The Master Bedroom: iPad

The Keypad’s may be plugged into any of the eight keypad ports. Source control IR emitters are plugged into the IR Ports. There are ten IR ports: IR1 thru IR8, and IR9 & IR10.

IR1 thru IR8 route source specific IR signals from connected keypads, while IR9 & IR10 output the common IR or the sum of all received IR signals.These Ports may be used for source equipment that is common to all zones.


Speakers in each zone are connected to the amplifier by “Home Run” speaker cables.

Preamplifier Zone Outputs

The preamplifier output zones are completely independent of the digital amplifier zones. These can be used in locations where a high or lower power amplifier / speaker is required.

A preamplifier zone may be connected to a secondary power amplifier for higher power amplification, or a preamplifier zone may be zone linked to one of the digital amplifier zones and provide line level outputs to a subwoofer.

Here's a thought!
If you are using a CasaTunes Music Server, you can also connect the pre-amplifier outputs to an AV Receiver, and enable CasaTunes to control the AV Receiver as if it were just another room in your home.

Source Equipment

The amplifier has eight stereo RCA audio inputs for connecting source equipment. These source inputs also feature a coax digital input. If a signal is present on the coax digital input it takes precedence over the analog input. There are four additional digital-only source inputs featuring both coax and optical inputs.

A zone may select from any of the connected sources. Someone in the Lounge may be listening to stream 1 from the CasaTunes music server while another in the Study may be listening to music from stream 2 on the CasaTunes music server.

All eight zones may select the same source, in such circumstances there is a possibility that all eight zones may be trying to control the same source – not always desirable – so a system should be well planned and where appropriate additional source equipment installed.

Multiple Amplifier Stacks

In larger installations multiple amplifiers can be linked together to increase the number of zones.

Figure 2 - How to stack multiple amplifiers

Figure 2 shows a stack of amplifiers with the source equipment connected to the first amplifier. These source inputs are converted to digital audio, buffered and then sent to the next amplifier in the stack. Use good quality coax digital shielded RCA cables. The cables should be < 3m (10 ft).

The maximum recommended expansion is eight units.

The Ethernet can be connected as shown. However, if a localEthernet router or switch is available and it has enough ports then connect each amplifier to the router / switch directly.

Using the Web Application

Here's a thought!
If you are using a CasaTunes Music Server, then using the web application to setup one or more amplifiers, is not required. Instead use CasaSetup to configure your amplifiers, sources, and rooms.

The CasaTunes CT-12X8 amplifier has a built-in web application which may be used for configuration, control and monitoring of amplifier functions.

To open the amplifier web application, enter either the IP address of the amplifier.  i.e.

Home Page

The home page provides access to the Amplifier Zones. Selecting a Zone opens its control page.

The first Zone defaults to the name Location 1, all other zones if unnamed are listed as Zone 2, Zone 3, etc.

View and manager  zones using the built-in CT-5X4MA and CT-12X8MA web interface

Zone Control Page

The Zone Control Page provides status & control of:

  • Standby
  • Mute
  • Volume:Slider or Up/Down button with readout
  • SourceSelection: S1 – S12, Media 1 and any Conditional sources  
  • If Media1 is the selected Source, then Media Navigation and Player functions are displayed

A blue button indicates the item is selected or is ON.

Because of Web browser limitations, Slider setting changes are made using a positional touch on the slider

The Zones button returns to the previous page.The Settings button opens the Settings page.

View the source selected for a zone using the built-in CT-5X4MA and CT-12X8MA web interface

Zone Settings Page

The Zone Settings Page provides status & control of:

  • Bass: Slider or Up/Down button
  • Treble: Slider or Up/Down button
  • Loudness  
  • Mono
  • Balance: Slider or Left/Right button
  • Gain: Slider or Up/Down button
  • Maximum Volume Limit: Slider or Up/Down button
  • Power On Volume: Enable with Slider or Up/Down button
  • Delays for each Source: S1 – S12: Slider or Up/Down button

The back arrow button returns to the Zone Control page.

View the zone settings for the selected  zone using the built-in CT-5X4MA and CT-12X8MA web interface

Configuration using the Web application

To access the configuration pages in the browser enter the IP address with a config extension. i.e. There are 5 configurations pages and a log page that may be selected

Device Configuration Page

The Device Configuration page provides Device information:

  • Model
  • Unit ID
  • Manufacturer Date 
  • Installed Firmware Version
  • Temperature of amplifier heat sink
  • IP Address
  • MAC Address
  • Amplifier assigned Network name

Wired Ethernet: The Network configuration is set to use DHCP by default. If a Static IP address is selected, then the IP settings will appear in a drop-down

Date & Time: Configure the NTP server and if/when Daylight Saving time is observed

If any of the settings have been changed they do not take effect until the Save Changes button has been selected

View the matrix amplifier device settings using the built-in CT-5X4MA and CT-12X8MA web interface

Sources Configuration Page

This allows you to rename the audio Sources on the amplifier – the names will appear on connected keypads and Tablets or Mobiles running the CasaTunes App. Source names have a maximum of 15 characters (less when using exotic characters)

The gain of each analog source may also be adjusted using the Left/right buttons. These changes happen live.

If any of the settings have been changed they do not take effect until the Save Changes button has been selected

View the source settings for the matrix amplifiers using the built-in CT-5X4MA and CT-12X8MA web interface

Zones Configuration Page

All CasaTunes amplifiers on the network are listed. The MAC address is displayed to show which unit is being configured. CasaTunes amplifiers have a MAC address label fixed either to rear panel or cover.

Zone Settings: The Zone name may be changed – click the name to edit. Zone names have a maximum of15 Characters (less when using exotic characters). These names will appear on connected Keypads and Tablets running the CasaTunes App

The amplifier physical Zones 1- 8 may be configured with a different logical zone or system zones: ranging from 0 – 95

Each Keypad port can have a zone assigned. This enables source specific IR routing and for keypads that support this feature, the keypad’s zone will be automatically assigned depending on its keypad port connection

Zone Linking: Zones can be linked together so that the source selection and optionally power and/or volume apply to all zones in the group.There is no limit to the number of zones in a group, but a zone may only be a member of a single group

If any of the settings have been changed they do not take effect until the Save Changes button has been selected

View the zone and key port assignments for the matrix amplifiers using the built-in CT-5X4MA and CT-12X8MA web interface

Media Servers Configuration Page

Servers is the list of network shares where music files are located.

UNC path is in the form \\server\share\ and may also include folder names. Enter the path of the connected Network share by clicking the Add button and editing the UNC path name

Username is generally required and is usually set to ‘guest’ for shares that are configured without a user. If a domain is required then the username is entered in the form ‘Domain\User’

Password is used when the user has an account with a password.

If any of the settings have been changed they do not take effect until the Save Changes button has been selected

View the media server settings for the matrix amplifiers using the built-in CT-5X4MA and CT-12X8MA web interface

IR Routing Configuration Page

IR signals received on any one of the IR inputs do not need to be transmitted on every IR output. Use of the IR Routing feature enables control over which IR outputs transmit an IR signal depending on its origin and optionally the currently selected source. Source specific IR routing is useful for controlling source equipment and is available for all keypad ports that have a zone selection on the zones page.

IR input selects the keypad port to configure for IR routing.

Selected IR Outputs is a table of check boxes that when checked transmits source related IR to specific IR outputs.

If any of the settings have been changed they do not take effect until the Save Changes button has been selected

View the IR routing assignments for the matrix amplifiers using the built-in CT-5X4MA and CT-12X8MA web interface

Management Page

IR signals received on any one of the IR inputs do not need to be transmitted on every IR output. Use of the IR Routing feature enables control over which IR outputs transmit an IR signal depending on its origin and optionally the currently selected source. Source specific IR routing is useful for controlling source equipment and is available for all keypad ports that have a zone selection on the zones page.

Diagnostic Log is a useful tool for diagnosing connection issues and possible faults. This log is not stored in memory, so information is only collected during the current active power cycle.

Events: Non-volatile log of certain parameters like power interruptions, high temperature events, etc.

View diagnostics and events for the selected  matrix amplifier using the built-in CT-5X4MA and CT-12X8MA web interface

Acknowledgements - FreeRTOS - uIP

The amplifier firmware is based in part on™ V5.0.2 and the uIP TCP/IP stack.

For more information on™ please visit

Source code for™ can be downloaded from their official website.

The following copyright and statements for uIP TCP/IP stack are required by license:
Copyright (c) 2001-2003, Adam Dunkels. All rights reserved.
Redistribution and use in source & binary forms, with or without modification, are permitted provided that the following conditions are met: