Cloud CX261 MP3 Zone Mixer Installation Guide

Cloud CX261 MP3 Zone Mixer

Product Information: CX261 MP3/Zone Mixer

The CX261 MP3/Zone Mixer is a versatile audio mixer designed for professional use. It allows users to mix and control multiple audio sources, including MP3 players, and distribute audio to different zones or speakers. The mixer is equipped with various input and output options, as well as additional features for enhanced audio control.

Key Features

• Multiple audio inputs and outputs
• Integrated MP3 player
• Zone control for distributing audio to different areas
• Front panel controls for easy operation
• Safety features to prevent electric shock and fire hazards

Specifications:

• Model: CX261
• Version: v1.5
• Product Dimensions: (Insert dimensions here)
• Weight: (Insert weight here)
• Power Requirements: (Insert power requirements here)

Product Usage Instructions

Installation

1. Choose a suitable location for the CX261 MP3/Zone Mixer.
2. Ensure that the mixer is placed on a stable surface and is properly grounded.
3. Connect the necessary audio sources, such as MP3 players or other devices, to the appropriate input ports on the rear panel of the mixer.
4. Connect the desired output devices, such as speakers or amplifiers, to the corresponding output ports on the rear panel.
5. Make sure all connections are secure and properly inserted.

Front Panel Controls
The front panel of the CX261 MP3/Zone Mixer features various controls for audio mixing and playback. Familiarize yourself with the following controls:

• Power Button: Press this button to turn the mixer on or off.
• Input Selectors: Use these selectors to choose the desired audio input source for each zone.
• Volume Controls: Adjust the volume levels for each zone using the dedicated volume controls.
• MP3 Player Controls: Control the playback of audio files from the integrated MP3 player using the provided buttons (play, pause, skip, etc.).

Zone Control:
The CX261 MP3/Zone Mixer allows you to distribute audio to different zones or speakers. Follow these steps to control the audio output to specific zones:

1. Select the desired audio input source using the input selectors on the front panel.
2. Adjust the volume levels for each zone using the dedicated volume controls.
3. To mute a specific zone, turn its corresponding volume control fully counterclockwise.
4. For enhanced control, refer to the user manual for advanced features and settings.

Safety Instructions
It is important to follow these safety instructions to ensure safe and proper usage of the CX261 MP3/Zone Mixer:

• Read and familiarize yourself with the user manual and safety instructions provided.
• Ensure that the mixer is properly grounded to prevent electric shock.
• Do not expose the mixer to rain or moisture to avoid the risk of fire or electric shock.
• Only use the provided power cord and plug. If the plug does not fit the outlet, consult an electrician for replacement.
• Avoid pinching or damaging the power cord, plugs, and connections.
• Do not open the product enclosure. Refer to qualified personnel for servicing or repairs.

For more detailed information on installation, operation, and safety, please refer to the complete CX261 MP3/Zone Mixer Installation and User Guide v1.5.

Safety Information

Important Safety Instructions
Read these instructions.

• Keep these instructions.

• Heed all warnings.

• Follow all instructions.

• Do not use this apparatus near water.

• Clean only with dry cloth.

• Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.

• Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.

• 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.

• Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.

• Only use attachments/accessories specified by the manufacturer.

• Use only with the cart, stand, tripod, bracket, or
  table specified by the manufacturer, or sold with the apparatus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.

• Unplug this apparatus during lightning storms or when unused for long periods of time.

• 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.

WARNING:
To reduce the risk of fire or electric shock, do not expose this appliance to rain or moisture.

CAUTION:
Use of controls or adjustments or performance of procedures other than those specified may result in hazardous radiation exposure.

CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN

WARNING: SHOCK HAZARD – DO NOT OPEN AVIS

• The lightning flash with the arrowhead symbol within an equilateral triangle, is intended to alert you to the presence of uninsulated dangerous voltages within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock.
• The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the appliance.
• The mains plug is used as the disconnect device and it should remain readily accessible during intended use. In order to electrically isolate the apparatus from the mains, the mains plug should be completely removed from the mains outlet socket.
• Meaning of the label: Evaluation for apparatus only based on temperate climate condition, therefore it’s the only operating condition applied for the equipment .There may be some potential safety hazard if the equipment is used in tropical climate region.
• Meaning of the label: Evaluation for apparatus only based on altitude not exceeding 2000 m, therefore it’s the only operating condition applied for the equipment .There may be some potential safety hazard if the equipment is used at altitude above 2000 m.

Conformities
This product conforms to the following European EMC Standards: BS EN 55103-1:2009, BS EN 55103-2:2009. This product has been tested for use in commercial and light industrial environments. If the unit is used in controlled EMC environments, the urban outdoors, heavy industrial environments or close to railways, transmitters, overhead power lines, etc., the performance of the unit may be degraded.
The product conforms to the following European electrical safety standard: BS EN 60065:2012

Safety Considerations and Information

The unit must be earthed. Ensure that the mains power supply provides an effective earth connection using a three-wire termination.

CAUTION – High Voltages
Do not touch any part or terminal carrying the hazardous live symbol while power is supplied to the unit.
Terminals to which the hazardous live symbol refers require installation by a qualified person.

CAUTION – Mains Fuse
Replace the mains fuse only with the same type and rating as marked on the rear panel.

• Fuse type: T1AH 250 V
• Fuse rating: 1 A
• Fuse Size: 20 mm x 5 mm.

CAUTION – Servicing
The unit contains no user serviceable parts. Refer servicing to qualified service personnel. Do not perform servicing unless you are qualified to do so.
Disconnect the power cable from the unit before removing the top panel and do not make any internal adjustments with the unit switched on.
Only reassemble the unit using bolts/screws identical to the original parts.

OVERVIEW

Introduction
The Cloud CX261 is a 1U rack-mounting stereo audio mixer intended for use in multi-use areas where simple control of high-quality background music needs to be combined with a flexible range of paging options.
The CX261 mixes any one of six stereo line inputs with one or two microphone inputs. Separate controls for music and mic levels are provided, and music source selection and level may be controlled remotely if wished, either using standard Cloud remote control plates, or from an AV control system (e.g., Crestron, AMX, etc.). As well as the main output, there is a transformer- isolated mono auxiliary output which is suitable for providing a MOH (Music On Hold) output to a telephone system.
The mixer may be configured to operate with most paging systems: either mic input may be activated by voice (VOX) or short-to-ground access connections, and MIC 1 may have priority over MIC 2 if wished. Also, one line input may have priority over any other selected to facilitate connection of a digital sound store or similar device.
A front panel 3.5 mm jack input permits easy connection of a portable MP3 player, laptop or similar, with independent level control.
A switchable isolating transformer configures MIC 1 input for direct connection to a telephone system, enabling paging messages to originate from an extension.
EQ cards to suit various installed-sound loudspeakers may be fitted to either or both channels.
A Music Mute input is provided to allow external systems such as fire alarm panels to disable background music in the event of an emergency. This is a function that may be required by Local Authority regulations.

What’s in the box
Unpack the CX261 and its accessories with care. It is always a good idea to store all packaging (if practical), in case you ever need to return the unit to your Cloud dealer for any reason.
As well as this manual, the shipping carton should contain the items listed below. Please contact your Cloud dealer immediately if any of them are missing or damaged.

• Cloud CX261 Zone Mixer
• IEC mains lead (AC cord) with moulded plug appropriate to the territory
• Set of mating connectors for all rear panel screw-terminal connectors

Main Features

• Stereo mic/line mixer for installed audio applications
• Six (unbalanced) stereo line inputs with individual gain controls
• Two electronically balanced mic inputs
• Front panel control of music source/level and both mic levels
• Front panel input (3.5 mm jack) for MP3 player, etc., with gain control (overrides rear panel LINE 1 input) and LED level indication
• Separate HF & LF EQ adjustments for music and mic sources
• Bi-colour LEDs to aid mic gain adjustment
• MIC 1 input configurable as transformer-isolated line input (with separate gain control) for connection to phone system
• MIC 1 priority over MIC 2 (selectable)
• Short-to-ground access connector or VOX-triggered voice-over-music priority on both MIC 1 and MIC 2 inputs
• Selectable LINE 6 priority with choice of release times
• Music Mute control input (N/O or N/C) for interface to emergency system
• Compatible with standard Cloud remote control plates: RL-1 Series (music level) and RSL-6 Series (music level and source selection)
• Electronically-balanced stereo main output
• Mixer can be configured by internal jumper for mono operation
• Transformer-isolated mono auxiliary output for use with telephone MOH systems
• Aux output source selection (internal jumper) – follows main output or always LINE 2
• Optional speaker EQ cards available
• 1U 19” rack mounting unit

Block Diagram

Description of front panel

1. MUSIC SOURCE – selects one of Music inputs L1 to L6.
2. MUSIC LEVEL – adjusts level of selected Music input.
3. LOCAL/REMOTE LED – indicates (green) when remote source selection is enabled.
4. MP3 input – 3.5 mm stereo jack socket for connection of non-permanent external source.
5. MP3 GAIN – adjusts gain of the MP3 input.
6. LINE 1/MP3 LED – indicates (green) when the MP3 input is enabled.
7. SIGNAL INDICATOR – 3 LEDs (green/yellow/red) indicating level of MP3 input.
8. MIC 1 LEVEL – adjusts level of Mic input 1.
9. MIC 2 LEVEL – adjusts level of Mic input 2.
10. MUSIC MUTE – indicates (red) when external Music Mute is active.
11. POWER – green LED, confirms power is applied to the unit.
12. Rack mounting ears – the unit may be rack-mounted in a standard 19” equipment rack. It requires 1U of rack height.

Description of rear panel

1. LINE 1 to LINE 6 – stereo line inputs for music sources.
2. GAIN – gain trims for each line input.
3. LF & HF MUSIC EQ – low and high frequency EQ adjustment for music channel.
4. RCA/MP3 – push-button switch: press in to replace LINE1 RCA connectors with front panel MP3 input.
5. MIC 1 and MIC 2 – balanced mic inputs.
6. GAIN – gain trims for each mic input.
7. LF & HF MICS EQ – low and high frequency EQ adjustment for mic channel.
8. MICS LEDs – bicolour LEDs to aid mic level adjustment.
9. MIC/TEL – push-button switch: press in to reconfigure MIC 1 input for use with telephone system.
10. TEL GAIN – MIC 1 input gain adjustment in TEL mode.
11. LEFT & RIGHT OUTPUTS – balanced main L & R outputs.
12. MOH OUTPUT – balanced auxiliary output for use with MOH systems.
13. MOH LEVEL – level control for MOH output.
14. Access control connector – external paging control inputs for MIC 1 (M1) and MIC 2 (M2)
15. RSL-6 – remote music control connector for RL-1 or RSL-6 remote control plates.
16. LOC/REM – disables front panel controls when remote control is in use.
17. MUTE CONTACTS – emergency control input for muting music source.
18. IEC mains input.
19. Mains fuse.

INSTALLATION

Hardware Considerations
The CX261 Zone Mixer is built in a 1U-high 19” rack mount enclosure. It is recommended that the Zone Mixer is installed in a 19” rack wherever possible. The unit is approx. 150 mm deep, but 250 mm of rack depth should be available to allow for rear connectors and cabling.
The CX261 has low power consumption and there should be no thermal problems. Other equipment may be installed above or below the CX261.
The choice of location will be dictated by the specifics of the system and building layout. It is recommended that wherever possible, the CX261 should be mounted in an equipment rack along with as many of the music sources (CD players, music servers, TV receiver boxes, etc.) and audio power amplifiers (driving the zone loudspeakers) as practical.
When deciding the Zone Mixer’s location, bear in mind that access to it will probably be required even if a full complement of remote controls is being fitted as part of the system, as some adjustments can only be made on the mixer itself.

Power Supply
The CX261 is fitted with a Universal power supply which can operate on mains voltages from 85 to 253 V. An IEC mains cable with a plug appropriate for your country is supplied. The unit’s power consumption is 10.1 W.
Fuses and ratings
The only user-accessible fuse is an AC mains fuse on the rear panel. Only replace a fuse with one of exactly the same type. The fuse rating is 1 A; the type is a T1AH, size 20 x 5 mm, with high breaking capacity.

System Connections

Music Sources
Connect the system’s various music sources to inputs LINE 1 to LINE 6. The inputs are unbalanced, on standard RCA jacks (phono sockets). All six inputs are stereo, with separate L and R connectors. The left and right channels remain separate for the main stereo output but are summed to mono for the Aux/MOH output. If connecting a mono source with only a single output, it may be connected to either the left or the right input (but see “Stereo/mono operation” on page 16 re configuring main output for mono operation). The sensitivity range available should allow most standard items of audio equipment such as computers/tablets, music servers and media receivers, etc., to operate at a satisfactory level. Note that Line 6 input can be configured to have priority over any other music source, see “Line 6 priority” on page 16; Line 1’s rear panel input can be disabled in favour of the front panel MP3 input, see “Front panel MP3 input” on page 11. Provided the music source is adjacent to the Zone Mixer, normal phono-phono (or 3.5 mm jack-to-phono leads can be used). Always avoid using pre-made leads of an unnecessary length.
If it is necessary to connect an item of source equipment with a balanced output, the ideal method is to use a balancing transformer between the source and the unbalanced input. Suitable audio transformers, which should have a ratio of 1:1, are readily available from major audio component suppliers. The transformer(s) should be mounted as close to the Zone Mixer as practical, and housed in a screened enclosure if they are not individually screened. The preferred connection method is shown below.

If transformers are not available, a balanced source may feed an unbalanced input directly as long as care is taken over how the connections are made. A variety of design techniques are in use to implement balanced outputs in audio equipment, and some designs require different wiring protocols to others. Installers are advised to check the manuals with each item for guidance on how the outputs should be connected to an unbalanced input.
However, the wiring methods shown below will work in a large number of cases :

Front panel MP3 input
To facilitate easy connection of digital audio devices such as portable MP3 players or laptop computers, a 3.5 mm stereo jack socket is provided on the CX261’s front panel ([4] at “Description of front panel” on page 8).

The MP3 input replaces Line input 1, and will only operate if the MUSIC SOURCE switch is set to L1/MP3. The front panel MP3 jack socket is selected instead of the rear panel LINE 1 phono sockets by setting the RCA/MP3 switch on the rear panel ([4] at “Description of rear panel” on page 9) to MP3. A green LED on the front panel ([6] at “Description of front panel” on page 8) illuminates to confirm the selection. When the MP3 input is selected, the music source connected to LINE 1 will no longer be available.

Microphone inputs
MIC 1 and MIC 2 inputs are intended for the direct connection of microphones. They are electronically balanced and transformerless with an input impedance of greater than 2 kohms and optimised for use with microphones of 200 to 600 ohms impedance. The screw terminal input connectors should be wired thus:

Unbalanced microphones may be used by connecting pin 2 to pin 1 (cable screen) in the mating (male) screw-terminal connector. 12 V phantom power is available, see “Phantom Power” on page 15.
Each mic input may be routed to the main output at any level. All microphone announcements automatically reduce the music level in that zone while the announcement is in progress; MIC 1 input also has priority over MIC 2 input (see “Microphone Over Music Priority” on page 17 for full details.)

Use of Mic 1 input with telephone system
MIC 1 input on the CX261 may be reconfigured to accept an audio input directly from a compatible telephone system. This permits announcements to be made from some (or any) internal telephone extensions in a building. Not all telephone systems are suitable for this application, and the system documentation should be consulted in detail to ensure compatibility.
In TEL mode, full galvanic isolation is provided between the CX261 and the telephone system. The audio (or “paging”) output of the phone system should be connected to the MIC 1 input in the normal way. The impedance of the input in TEL mode is 600 ohms; this should be suitable for the majority of telephone systems. If the telephone system requires a high input impedance, internal jumper J16 may be removed to provide an input impedance of 48 kohms. See page 20 for location of internal jumpers.
The TEL GAIN preset gain control ([10] at page 9) should be adjusted with a test call from the telephone system. Note that the front panel MIC 1 LEVEL control is still operational.

Paging Access Control
Access control for both microphone inputs is provided to allow the CX261 to be interfaced to single-zone paging mics such as the Cloud PM1. The access contacts work on the short-to-ground system, which is compatible with the majority of paging microphones.
The CX261 is shipped with the access control input disabled for both microphone inputs. This allows immediate use with standard microphones not fitted with PTT (Press-to-Talk) switches. If external access control is required, the internal jumpers J6 (Mic 1) and J7 (Mic 2) must first be removed. See page 20 for location of the jumpers.
The access control input is a 3-pin 5 mm-pitch screw terminal connector on the rear panel ([14] at page 9). Mic input 1 becomes active when M1 is connected to 0V; Mic input 2 becomes active when M2 is connected to 0V.

See also the section “Priorities” for further information on the use of the CX261 with paging microphones.

Main Output
Connect the inputs of the power amplifiers feeding the loudspeakers for each zone to the LEFT and RIGHT OUTPUT connectors. Note that the main output is stereo by default; it may be reconfigured to operate in mono by moving internal PCB jumper J4 (see page 20). The outputs are balanced and will drive input impedances down to 600 ohms. Nominal output level is 0 dBu (775 mV). The output is designed to drive professional/industrial power amplifiers with balanced inputs (typically on XLRs). In this case, wire as the diagram below. Note that the screen can be left unconnected at the source end if earth loops are a problem.

Amplifiers with unbalanced inputs:
If audio amplifiers with unbalanced inputs are being used (e.g., hi-fi amplifiers), the following wiring should be adopted:

MOH/Auxiliary Output
The MOH (Music On Hold), or auxiliary output, provides a transformer-isolated L+R mono sum of the music channel. This is intended to provide a continuous music feed for use with a telephone system. If it is not required for this, it may be used as a auxiliary mono output for another suitable purpose. However, it should be noted that a fixed LF filter reduces bass frequencies from this output to optimise it for use with telephone systems. The microphone inputs are not mixed into this output, so that internal paging announcements are not heard by telephone callers. This fact should be borne in mind if the output is used for some other purpose.
The output is a 3-pin 3.5 mm-pitch screw terminal connector on the rear panel ([12] at page 9). The output level is -6 dBu (nominal) and is suitable for driving 600 ohm loads.
The output is transformer-coupled to provide full galvanic isolation from a telephone system. Because of this, pin 2 (cold/-) must always be connected. If wiring to an unbalanced input, the convention shown below should be followed :

Music Control
Like many other Cloud products, the CX261 allows remote control of music level and source selection. Cloud remote control plates from the RL-1 Series (music level only) and RSL-6 Series (music level and source selection) provide an elegant solution, though control via a DC voltage from third-party systems is also possible (see “Control of music source and level via external DC” on page 18).
Both types of remote control plate connect via the RSL-6 port (see [15] on “Description of rear panel” on page 9). This connector is a 3-pin 5 mm-pitch screw terminal type.

Connecting an RL-1 Series remote control plate
Wire the remote control plate as shown below. Either single-core screened or twin-and-screen cable may be used; in the case of the latter, ignore one of the cores. Maximum reliable cable run is 100 m.

Before the RL-1 will operate, the RSL-6 port must be enabled by setting the adjacent LOC/REM push-button switch ([16] on page 9) to REM (i.e., pressing it in). In this setting, the front panel MUSIC LEVEL and SOURCE controls become inoperative. As music source selection will still be required from the mixer’s front panel when an RL-1 is in use, the REM setting may be overridden for the source selection control only by moving internal jumper J14 to FR on the internal PCB. See page 20 for location of internal jumpers.

Connecting an RSL-6 Series remote control plate
Wire the remote control plate as shown below. Twin-and-screen cable should be used. Maximum reliable cable run is 100 m.

Before the RSL-6 will operate, the RSL-6 port must be enabled by setting the adjacent LOC/REM push-button switch ([16] on page 9) to REM (i.e., pressing it in). In this setting, the front panel MUSIC LEVEL and SOURCE controls become inoperative.

Music Mute
External muting of music is available at the MUTE CONTACTS connector ([17] at “Description of rear panel” on page 9). National or Local Authority regulations governing such systems may require that normal programme material (i.e., music) should be muted in an emergency, to ensure that any emergency messages are clearly audible.
The Music Mute input is on a 2-pin 5 mm-pitch screw-terminal connector. It should be connected to the appropriate alarm output on whichever building management system registers the alarm (typically the Fire System). The alarm output must be volt-free; if no such output is available, an intermediate relay or other isolation device must be installed between the alarm output and the Music Mute input.
The Mute input can be set to operate on either normally open (N/O) or normally closed (N/C) contacts via an internal jumper (see “PCB jumper location and settings” on page 20). The factory default setting is N/O, thus requiring a short-circuit to be applied across the two pins of the connector for muting to occur.
Visual indication of muting being activated is given by the MUSIC MUTE LED on the front panel.

SETTING UP & OPERATION

Music Inputs

Gain & level
To avoid dramatic changes in volume when switching between sources, the CX261’s music inputs are provided with preset gain trim controls ([2] on “Description of rear panel” on page 9). These vary the input sensitivity from -12 dBu to +12 dBu (approx. 200 mV to 3.1 V). When setting the system up, play audio from all the sources in use and listen to them one at a time at a reasonable volume. Taking a source of “average” volume as the reference, the gain controls of the others should be adjusted so that there is no appreciable difference in volume between any of the sources. (With a typical music source, setting the gain on its channel to mid-way is a good starting point.) Note that consideration may need to be given to the type of programme in use, particularly if one or more sources are TV sound.
In normal operation, the music level is set with the MUSIC LEVEL control on the front panel ([2] on “Description of front panel” on page 8). This control will not be operative if the rear panel LOC/REM push-button is set to REM. When setting the audio system up, set the gain controls (if any) on the power amplifier(s) to minimum, then turn the MUSIC LEVEL control on the mixer to maximum. Then increase the zone volume by turning up the power amplifier gain until it is as loud as will be required in normal use. This method ensures that excessive volumes will not be possible with the mixer’s operational controls.
Note that the setting of the MUSIC LEVEL control has no effect on microphone or paging volume.

Front panel MP3 input
The MP3 input is enabled by setting the rear panel LINE 1/MP3 switch to MP3, and then selecting LINE 1/MP3 on the front panel MUSIC SOURCE selector switch. To allow for the wide range of signal levels which may be encountered from portable audio devices, the MP3 input is provided with its own level control and signal level LEDs ([5] and [7] respectively at page 8). The range of sensitivity adjustment is from -20 dBu (with the control fully clockwise, at “20”) to +4 dBu (with the control fully anticlockwise at “-4”).
Three LEDs are fitted to the front panel to aid level adjustment. The LEDs illuminate at the levels shown in the table:

With an MP3 player (or other source) connected to the MP3 input and playing, and the MP3 input selected, the level control should be adjusted so that the green and yellow LEDs are on more or less continuously and the red LED only on during the louder passages.

Local/remote control
If an RL-1 or RSL-6 Series remote control plate is in use, the rear panel LOC/REM push-button must be set to REM (button in) for the remote control to be operative and for the corresponding front panel controls to be disabled. If remote control is not required, the switch should be left at LOC (button out).
The setting of the internal PCB jumper J14 is also relevant. The default setting for this jumper is SW. This means that music source selection for the zone will be determined by the zone’s rear panel LOC/REM switch position: it will be via the front panel MUSIC SOURCE control when it is set to LOC and via a remote plate or other external control when it is set to REM. If J14 is moved to its alternative setting of FR, the source selection will always be made with the front panel control whatever is connected at the rear panel or the setting of the LOC/REM switch. If external control of music level only (i.e., not source selection) is required, the jumper should be set to FR and the LOC/REM switch to REM.
The diagrams below summarise the options:

Music EQ
Treble and bass equalisation for the music signal is provided via rear panel pre-set MUSIC EQ controls ([3] at “Description of rear panel” on page 9). This allows the installer to tailor the response of the Zone Mixer’s music channels to suit the acoustics and loudspeakers in each zone. The EQ controls are marked HF and LF; the HF control has a range of +/-10 dB at 10 kHz and the LF control a range of +/-10 dB at 50 Hz. A flat frequency response is achieved by positioning the slots on the controls in the horizontal plane.
Note that the MUSIC EQ controls do not affect the music signal at the MOH/Auxiliary output.

Music Limiter
The music channel of the CX261 incorporates a limiter circuit to help prevent inadvertent overloading of subsequent power amplifier input stages and ultimately, the installed loudspeakers. The limiter has no external controls. If the music input gain and level controls are set correctly, the limiter action should be inaudible on normal programme material, with no compression artefacts.
The threshold of the music limiter is factory set at 0 dBu, thus signal peaks above this level will be limited. A higher threshold of +6 dBu can be set by moving internal jumper J15 (see “PCB jumper location and settings” on page 20 for jumper location); this will give improved fidelity, and may be appropriate if the installer is confident about the dynamic range of the programme material.
If there is dynamics control elsewhere in the system (e.g., in the form of an external compressor/limiter or within a DSP-based unit), or if limiting is considered undesirable, the limiter may be by-passed by removing J15 from the PCB header.

Microphone Inputs

Phantom Power
Each microphone input has 12 V phantom power available. This will be adequate to power a wide range of condenser microphones. (Some “studio quality” mics may require a higher phantom voltage and thus necessitate an external PSU.) To enable phantom power at the mic inputs, the internal PCB jumpers J1 (Mic 1) and/or J2 (Mic 2) should be moved to their ON positions. See “PCB jumper location and settings” on page 20 for jumper locations.
Phantom power should NOT be enabled if dynamic microphones are to be used.

Gain & level
Each microphone input is provided with a rear panel preset GAIN control ([6] at page 9). A wide range of gain is available (10 to 50 dB), and there should be no problem in obtaining a satisfactory level from any normal microphone.
Immediately below each GAIN control is a bi-colour (green/red) LED ([8] at page 9) which monitors input signal level. These can be used to adjust the GAIN preset. During an announcement made in a normal speaking voice, adjust the GAIN control so that the LED (for the mic input in use) illuminates green fairly steadily. An occasional red flash is acceptable, but If red shows persistently, turn the GAIN control down slightly. Note that a signal level of -24 dBu is required to trigger the green LED while a level of 0 dBu will initiate limiter action (see “Microphone Limiter” on page 16), which may have an audible effect on audio quality.
In normal operation, the mic level in each zone is set with the MIC 1 LEVEL and MIC 2 LEVEL controls on the front panel ([8] & [9] on “Description of front panel” on page 8).

EQ
Two-band equalisation adjustment is provided for the microphone signals: note that these affect both MIC 1 and MIC 2 inputs. The MICS EQ pre-set controls are on the rear panel ([7] at “Description of front panel” on page 8). The equalisation is optimised for the tonal correction of speech signals: the HF control provides +/-10 dB at 5 kHz whilst the LF control provides +/10 dB at 100 Hz. A flat frequency response is achieved by positioning the slots on the controls in the horizontal plane.

High Pass Filter
Each mic input has a fixed 100 Hz high-pass filter to remove the lowest frequencies. This helps to reduce the effects of breath blasts and microphone handling noise. The filter is always in circuit.

Microphone Limiter
The microphone channel incorporates a limiter circuit to prevent amplifier and speaker overloading and also to help maintain more constant speech volume when the system is used by different announcers. The limiter is set to restrict the mic signals to a nominal 0 dBu, and if the mic gain and level are set correctly, should be inaudible in operation on normal speech. There are no internal or external controls.

Use of Mic 1 input with a telephone system
MIC 1 input may be reconfigured to accept an audio input directly from a compatible telephone system.
The MIC/TEL button on the rear panel ([9] at page 9) should be in the TEL position (in) for this application. This inserts a transformer in series with the input connector to provide full electrical isolation from the telephone system, together with an independent gain control stage.
The TEL GAIN preset gain control ([10] at page 9) should be adjusted with a test call from the telephone system. Note that the front panel MIC 1 LEVEL control is still operational.

Main Outputs
In normal operation, the music level will be set by the front panel MUSIC LEVEL control, or by a corresponding control on a remote plate. Follow the procedure described previously (page 15) to adjust the music level in each zone.

Stereo/mono operation
The CX261 is a 2-channel device, and is intended to be used where full stereo reproduction of music sources is desirable. If the installation does not require full stereo operation (which will generally be dictated by room layout and loudspeaker placement), mono mode should be selected. Mono mode is enabled by moving internal jumper J4 from STEREO to MONO.
In mono mode, the LEFT and RIGHT outputs will carry identical programme at the same level. Either or both may be used as wished.
Note that stereo music sources should still be connected to both L and R line inputs in the normal way. However, when mono operation is enabled, any mono music sources may be connected to either L or R only.

MOH/Auxiliary Output
The signal level at the MOH/Aux output can be set independently, via the rear panel preset MOH LEVEL control ([13] at page 9). The output level is zero with the control fully anticlockwise. Note that the signal at this output is NOT altered by the front panel MUSIC LEVEL control or the rear panel MUSIC EQ preset adjustments.

Source Selection
If the output is to be used as an auxiliary mono feed, it will generally need to follow the normal music source selection. This is the factory default configuration. If Music Priority is enabled (see “Line 6 priority”), the MOH/Auxiliary output will switch to Line 6 along with the main outputs if the input becomes active.
However, when in use as an MOH source, it is generally more desirable for the music source (typically a CD jukebox or music server) to remain constant, and not vary with the front panel MUSIC SOURCE control. For this purpose, the source for the auxiliary/MOH output can be altered, by moving internal jumper J8 from SEL to LINE 2. The music source that is intended to provide the Music On Hold programme should be connected to LINE 2. See “PCB jumper location and settings” on page 20 for location of the internal jumper.
In either case no microphone signals are present at the MOH/auxiliary output, thus announcements made via the microphone inputs do NOT interrupt music programme at this output, regardless of any priority settings.

Priorities
The CX261 offers several options for determining what happens to music signals when announcements are made. The options are selected via internal jumpers, and should be set to suit the requirements of the installation when the system is installed. See page 20 for location of the internal jumpers.

Line 6 priority
Line input 6 can be set to have priority over other music inputs. When set, the CX261 will automatically switch the music source to Line 6 when the signal level at Line 6 input exceeds -30 dBu (approx.) The input set by the source selection switch is temporarily deselected until the signal at Line 6 input stops, when it resumes, smoothly increasing in level to its former volume. The restoration time is selectable, options are 3, 6 or 12 seconds.
This facility is useful with sources such as spot announcement players, jukeboxes, digital sound stores or similar, as audio from these sources will always automatically replace any previously selected programme for its duration.
Music Priority is set by moving internal jumpers J5A and J5B from OFF to ON. See page 20 for location of internal jumpers.
The factory default restoration time is 3 seconds. This may be too short in some cases; for example, if a jukebox was to take more than 3 seconds between the end of one track and the start of the next. In such a case, longer restoration times of 6 or 12 seconds may be set to ensure that the CX261 does not revert back to the selected music source in between tracks.
Restoration time is set by internal jumper J3. Moving the jumper position on the 3-pin header changes the restoration time from 3 s to 6 s; removing the jumper altogether sets a time of 12 s. See “Microphone Over Music Priority” below for more information. Note that Music Priority applies to both the main outputs and the MOH/Auxiliary output.

Microphone Priorities
The microphone inputs on the CX261 may be configured so that when they are in use, they take priority over the music programme; additionally, Mic input 1 may be set to take priority over Mic input 2.
There are two methods of triggering the microphone priority circuitry: signal detection (AVO) or via the zone access contacts on the rear panel (ACC). The choice is made by internal jumpers J11 (Mic input 1) and J12 (Mic input 2); note the two mic inputs may be set differently if wished. See page 20 for location of the jumpers.
The factory default is for both mic inputs to be set to AVO (Automatic Voice- Over). In this mode, the priority circuit is triggered by the presence of a signal at the microphone input. The alternative ACC jumper setting triggers the priority by contact closure when the access contacts are enabled. ACC priority should only be selected when a suitable paging microphone is used.
Note that priority detection may be disabled by removing J11/J12. In this state, the mic channels will still operate normally, but music programme will remain at full level, and the two mic inputs will be mixed together if both are active simultaneously.

Microphone Over Music Priority
The priority circuitry is configured at the factory to mute the music programme when an announcement is made. At the completion of the announcement, the music ramps back up to its original level over a time period of 3, 6 or 12 seconds, according to the setting of J3. The muting action can be overridden by moving internal jumper J13 from the ON position to the OFF. See page 20 for location of internal jumpers.

Mic 1 Over Mic 2 Priority
In installations where both mic inputs are being used, it is possible for announcements to clash if the mics are active simultaneously. By default, the CX261 allows both microphones to access the system simultaneously. MIC 1 may be given priority over MIC 2 by moving internal jumper J10 from the OFF position to the ON. (See page 20 for location of internal jumpers.) Then, if MIC 1 is already making an announcement, MIC 2 will not be able to access the system. Also, if MIC 2 is making an announcement and MIC 1 then becomes active, MIC 2’s announcement will be curtailed and MIC 1’s will take over.

OPTIONS AND ADDITIONAL INFORMATION

RL-1 Series and RSL-6 Series remote control plates – general considerations
Cloud RL-1 Series and RSL-6 Series remote control plates are available in three form factors: two fit single-gang UK or American electrical back boxes respectively, while the third is a 50 x 50 mm “Media” module, suitable for “Euro-module” mounting frames available in most European countries. Back boxes of either the recessed type or surface-mounting type may be used, providing they are at least 25 mm deep.
Each plate should be connected to the rear panel RSL-6 port using single- or twin-core screened cable as described at “Music Control” on page 12. The plate terminations are conventional screw terminals and the RSL-6 port on the mixer is a 3-pin 5 mm-pitch screw terminal connector.
The remote control plates are passive and thus do not draw any significant current from the mixer.

Control of music source and level via external DC
It may be necessary in some installations to adjust the music level and select music source from an external control system (e.g., Crestron, AMX, etc.). If the RSL-6 port is not required for an RL-1 or RSL-6 Series remote control plate, it may be used to receive DC voltages from the external system to effect these adjustments.
Both music source selection and level can be controlled over their full ranges with a DC voltage of 0 to +10 V. The pinout of the RSL-6 port is as follows:

NOTE: If the control voltage source is not isolated from the power earth, there is a small risk of creating a ‘ground loop’ by linking the mixer technical ground (0 V) to the ground (0 V) of the equipment supplying the control voltages. To minimise this risk, we suggest that all pieces of equipment be in close proximity, and supplied from the same power outlet.

Music level
Music level in a zone may be varied over its full range by applying a DC voltage of between 0 and +10 V to pin 2, the 0 V reference being connected to Pin 1. 0 V on pin 2 corresponds to full level and +10 V will produce maximum attenuation. Between these two voltages, the rate of attenuation is approximately 165 mV/dB.
Note that there is an internal 4k7 “pull-up” resistor between pin 2 and the internal +12 V rail. If pin 2 is left “floating”, this pull-up will result in full attenuation. The output impedance of the control voltage source should be low enough to overcome the effect of this resistor.

Music source
Music source for a zone may be controlled by applying various DC voltages of between 0 and +10 V to pin 3, the 0 V reference being connected to pin 1. 0 V at pin 3 will select Line input 6 and between +7.5 and +9 V will select Line input 1. The other line inputs will be selected with intermediate voltages. Taking pin 3 above +9 V will deselect all inputs, making the zone effectively ‘off’ for music.
The table below lists the DC voltages required at pin 3 to select each line input. The third column is the value of a resistor which should be connected between pins 1 and 3 to permanently ‘force’ a zone to a particular line input.

Note that there is an internal 15k “pull-up” resistor between pin 3 and the internal +12 V rail. If pin 3 is left “floating”, this pull-up will cause ‘OFF’ to be selected. The output impedance of the control voltage source should be low enough to overcome the effect of this resistor.

Fitting loudspeaker EQ cards
The CX261 is compatible with various popular installed-sound loudspeakers; a single-channel loudspeaker equalisation module may be fitted in the left or right channel of the main output (either or both) to optimise the frequency response of the channel to the loudspeaker type being used. Note that there is no provision for fitting an equalisation module to the MOH/Auxiliary output.
Please check the Cloud website (www.cloud.co.uk/accessories) for makes and models of loudspeakers for which EQ cards are available.

1. Switch off the power and isolate the CX261 from the mains.
2. Remove the top panel (6 screws).
3. Plug the equalisation module onto its connector; note that the connector has two notches on one side which engage with lugs on the module’s mating connector to ensure correct orientation.
4. Replace the top panel.

See the Appendix section “PCB jumper locations and settings” at page 20 for further details. Replace the top cover with the original screws after fitting.

APPENDIX

PCB jumper location and settings
The CX261 has various internal PCB-mounted jumpers, the setting of which may require alteration during installation. The table below lists each switch and jumper and its purpose, together with the factory default setting.

OFF

J2| Mic 2 phantom power

J3

|

Priority release time

| 3S: 3 seconds. release time 6S: 6 seconds release time

ABSENT: 12 seconds release time

|

3S

J4

|

Mono/stereo operation

| MONO: L&R music inputs are summed STEREO: normal operation|

STEREO

J5 (A&B)

|

L6 priority (left & right)

| OFF: no priority – normal operation

ON: L6 has VOX-triggered priority over other sources

|

OFF

J6

|

MIC 1 access bypass

| PRESENT: MIC 1 always active

ABSENT – use M1 pin on access port to activate MIC 1

|

PRESENT

J7

|

MIC 2 access bypass

| PRESENT: MIC 2 always active

ABSENT – use M1 pin on access port to activate MIC 2

|

PRESENT

J8

|

MOH source select

| SEL: MOH/Auxiliary output follows music source selection L2: MOH/Auxiliary output is always LINE 2|

SEL

J9

|

Music Mute configuration

| NO: external contact closure required for muting NC: external contact opening required for muting|

NO

J10

|

MIC 1 over MIC 2 priority

| OFF: Mics have equal priority

ON: MIC 1 has priority over MIC 2

|

OFF

J11

|

MIC 1 priority trigger

| AVO: MIC 1 priority triggered by announcement (VOX)

ACC: MIC 1 priority triggered by contact closure

ABSENT: no MIC 1 priority: music remains at full level during announcements

|

AVO

J12

|

MIC 2 priority trigger

| AVO: MIC 2 priority triggered by announcement (VOX)

ACC: MIC 2 priority triggered by contact closure

ABSENT: no MIC 2 priority: music remains at full level during announcements

|

AVO

J13

|

Mic over music priority

| OFF: music remains during announcement ON: music mutes during announcement|

ON

J14

|

REM mode source selection

| FR: permits front panel source selection in REM mode SW: front panel source selection disabled in REM mode|

SW

J15

|

Music limiter threshold

| 0dBu: music level limited to 0 dBu

+6dBu: music level limited to +6 dBu ABSENT: No music limiting action

|

0dBu

J16

|

TEL input impedance

| PRESENT: Mic 1 input impedance 600 ohms ABSENT: Mic 1 input impedance 48 kohms|

PRESENT

J5 consists of two jumpers; they should be moved as a pair

The diagram below shows the locations of the CX261’s internal PCB jumpers (not to scale).
If any jumpers need to be changed, turn the Zone Mixer off and disconnect it from the mains. Undo the 6 screws securing the top cover of the unit and remove it. Use a pair of small pliers to gently remove the jumpers from the PCB headers and reposition them as required.
The diagram also shows the locations of the socket for the optional loudspeaker EQ cards.

Ground loops
If, despite your best efforts, the completed sound system ‘hums’ you probably have a ‘ground loop’. The offending signal source can often be identified by setting the volume control to minimum, then disconnecting the input leads (both left & right channels) on each line input until the ‘hum’ disappears. This problem is often caused by terminating a screened input cable into a signal source positioned a significant distance from the mixer. A good way of avoiding this potential problem is to use signal sources (CD players and the like) that are double insulated with no connection to the mains supply earth. If a signal feed were derived from a second mixer (a club or microphone mixer for example) it would be perfectly normal to expect this to be earthed; we suggest that a transformer be used to isolate the signal and prevent a noisy loop (see “Music Sources” on page 10).

EMC considerations
The Cloud CX261 fully conforms to the relevant electromagnetic compatibility (EMC) standards and is technically well behaved; you should experience no operational problems and under normal circumstances, no special precautions need to be taken. If the unit is to be used within close proximity to potential sources of HF disturbance such as high power communications transmitters, radar stations and the like, the performance of the mixer may be reduced; we suggest that the microphone cable screen be connected to the equipment chassis and the line input leads are kept as short as possible.

Technical Specifications

Line Inputs:

Frequency response| 20 Hz to 22 kHz, +0/-0.5 dB
Distortion| <0.05% typical @ 1 kHz
Sensitivity| 0.775 V (0 dBu), +/-12 dB
Input gain control range| 24 dB
Input impedance| 48 kohms
Headroom| >20 dB
Noise| -88 dB typical, 20 Hz to 22 kHz
Equalisation| LF: +/-10 dB @ 50 Hz; HF: +/-10 dB @ 10 kHz
MP3 input:
Frequency response| 20 Hz to 20 kHz, +/-0.5 dB
Distortion| <0.05% @ 1 kHz
Sensitivity| -20 dBu to +4 dBu
Input gain control range| 24 dB
Microphone Inputs:
Frequency response| -3 dB @ 100 Hz (filter) to 20 kHz, +/-0.5 dB
Distortion| <0.05%, 20 Hz to 22 kHz
Sensitivity| -10 dBu to -50 dBu
Gain range| 40 dB
Input impedance| >2 kohms (balanced)
Common mode rejection| >70 dB @ 1 kHz
Headroom| >20 dB
Noise| -125 dB EIN, 20 Hz to 22 kHz, 150 ohms source
Equalisation| LF: +/-10 dB @ 100 Hz; HF: +/-10 dB @ 5 kHz
Telephone Input:
Frequency response| -3 dB @ 100 Hz (filter); <-0.5 dB @ 20 kHz
Distortion| <0.05%, 200 Hz to 22 kHz
Sensitivity| -20 dBu to +4 dBu
Input Gain control range| 24 dB
Outputs:
 | Main| MOH/Auxiliary
Output level (nominal)| 0 dBu| -6 dBu
Output level (max.)| +20 dBu| 0 dBu
Minimum load impedance| 1.2 kohms| 600 ohms
General:
Power input| 85 V to 253 V AC, 50/60 Hz
Current consumption| 46.5 mA at 240 V
Fuse rating| 1 A
Fuse type| T1A, 20 x 5 mm
Dimensions (WxHxD)| 482.6 mm x 44 mm (1U) x 152.5 mm 19” x 1.73” (1U) x 6”
Weight| 2.13 kg

4.69 lb

www.cloud.co.uk
www.cloudusa.pro

References

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