The multiple channels of each of these amplifiers provide a convenient means of supplying different areas or systems with dedicated programme. With a varying number of inputs and power ratings, amplifiers from 50W to 400W per channel. Remote control and 100V/70V line accessories are offered.
Perhaps used in conjunction with the mixing and zoning devices from the same manufacturer, the facilities and accessories help integrate the designs into entertainment, conference and industrial environments, whilst other applications may well occur, such as tri-amplification or bi-amplification of stereo speakers, or effects, cue or monitor feeds. Brochures and manuals are available from www.cloud.co.uk.
A cost-effective 2-channel solution for commercial premises where a choice of low impedance or 25/70/100V line output is required. Each output channel provides a continuous output of 120watts, 1kHz continuous sine wave, with a frequency response of 20Hz to 20kHz.
The front facing panel of the 2U rackmountable amplifier hosts only a rocking power switch to the right side, and LEDs to provide illustration of power as well as protection, clip, and signal for each of the two channels. A slotted panel allows for ventilation and forced air cooling within the amplifier carcass.
The rear facing panel hosts all input and output connectivity and switching, including input level attenuators via a small slotted dials, a 65Hz high pass filter on/off switch per channel, and AC mains input via IEC connection. All audio connections are via Phoenix style terminal connectors.
Input impedance: 47kohms. Headroom: 16dB. Noise: Less than -85dB, 22kHz bandwidth. Power consumption: 14W, 20.8Va, idle; 206W, 260VA, 1/8th power; 230W, 280Va, 1/3rd power. Dimensions: 482.6 x 88 x 310mm (WxHxD). Weight: 10.9kg.
This amplifier has all the attributes of the VA2120 however it has four input channels and four output channels. With the exception of the duplicate channels and a second cooling fan, all switching and functionality is the same.
Input impedance: 47kohms. Headroom: 16dB. Noise: Less than -85dB, 22kHz bandwidth. Power consumption: 27.5W, 20.8Va, idle; 418W, 260VA, 1/8th power; 562W, 280Va, 1/3rd power. Dimensions: 482.6 x 88 x 408mm (WxHxD). Weight: 18.2kg.
A lower powered, four-channel version, the CX-A450 has similar input and output ports and facilities to the CX-A6. All signal inputs use three-pin ‘mini Phoenix’ two-part terminal connectors. Outputs use the larger Phoenix variants. The cooling fan is varispeed. A version with integrated mono mixer and zoner is also available, see Zone amplifiers. The CX-A450 can take an internal 100V/70V line module, see optional accessories.
Rated output per channel: 50W/4 ohms, 35W/8 ohms. Power source: 230V AC 40-60Hz. Dimensions: 2U (88mm) x 325(d)mm. Weight: 7.2kg.
Included accessories: AC power lead, comprehensive manual.
Optional accessories: A four-channel 100V/70V line distribution module, the CXL-4160, may be fitted internally. Alternatively see Cloud 100V Line transformers for suitable CXL-40T output transformer modules and dedicated rack mounting panel. Up to four VCA-5 modules may be fitted internally, each controlling one channels of amplification. Each VCA-5 may be operated in conjunction with an RL-1 control plate for individual channel adjustment.
The CX-A850 is an eight-channel version of the CX-A450. It has the same features, performance and dimensions, other than the extra inputs, and the resulting lack of space for fitting an internal 100V/70V line module.
Rated output per channel: 50W/4 ohms, 35W/8 ohms. Power source: 230V AC 40-60Hz. Dimensions: 2U (88mm) x 325(d)mm. Weight: 8.8kg.
Included accessories: AC power lead, comprehensive manual.
Optional accessories: See Cloud 100V Line transformers for suitable CXL-40T output transformer modules and dedicated rack mounting panel. Up to eight VCA-5 modules may be fitted internally, each controlling a channel of amplification. Each VCA-5 may be operated in conjunction an RL-1 control plate for individual channel adjustment.
CA2250 is a Class-D amplifier that offers two channels of output into low impedance (4 or 8ohm systems), or 70/100V line systems. Each output of the CA2250 gives a maximum of 250W, and it is capable of analogue audio input via balanced/unbalanced 3-pin plug-in screw-terminal connectors, or Dante audio network input when the optional CDI-CA2 Dante board is retrofit.
When using the amplifier as part of a 70/100V line system, the maximum output of odd and even channels can be shared. This means, on the larger amplifiers like CS4250, CS6160, and CA8125, all of the even channels can together produce a maximum of 500W, and the odd channels can do the same. This is particularly useful when installing into a venue where multiple rooms with 70/100V line have differing numbers of speakers.
CA2250 has energy efficient properties including channel mute function that operates when no input signal has been detected for 15minutes. The amplifier immediately ‘wakes up’ the channel or group when an input signal is detected. If no input signal is detected for 25minuts, the automatic power down (APD) feature moves the channel or group into a low-power standby mode to consume less than 2.5W when all channels are switched. The user can alternatively use the remote standby/wake up function which uses external contact closure to operate.
The front facing panel features vents for forced-air cooling, along with LEDs to signify signal, peak, protection, and powered. The number of LEDs depends on the number of channels on the amplifier – in the case of CA2250 there are two of each LED. A power button allows the on/off switching of the amplifier. The rear facing panel again houses vents for cooling, mains IEC connection, and input connection via 3-pole, 3.5mm-pitch plug-in screw-terminal connectors. There is also a 2-pin connector for remote power down functionality when using external closure switching, connector for speaker output channels one and two, and a host of dip switches to switch channel Hi-Z/Lo-Z output, 4ohm/70V or 8ohm/100V, input routing, APD (auto power down) on/off, and channels one/two high pass filter – which is set at 65Hz.
Maximum output power: 500W, all channels driven. Outputs: 4/8ohms/70/100V. Frequency response: 20Hz – 20kHz, +/-1dB. Distortion: 0.0019% THD, at 1kHz, 1dB below rated output. Crosstalk: Less than -98dB at 1kHz, -79dB at 10kHz. Input sensitivity: 0dBu, 0.775Vrms. Input impedance: 10kohms, balanced; 5kohms, unbalanced. Power input: 85-265V AC, 50-60Hz. Dimensions: 482.6 x 88 x 231.3mm (WxHxD). Weight: 4.5kg.
This amplifier has two channels capable of driving a maximum of 500W per channel. Dimensions (WxHxD): 482.6 x 88 x 381.8mm. Weight: 6.75kg. All other functional properties and audio specifications are the same as CA2250.
This amplifier has four channels capable of driving a maximum of 250W per channel. Dimensions (WxHxD): 482.6 x 88 x 381.8mm. Weight: 7.10kg. All other functional properties and audio specifications are the same as CA2250.
This amplifier has six channels capable of driving a maximum of 160W per channel. Dimensions (WxHxD): 482.6 x 88 x 381.8mm. Weight: 7.55kg. All other functional properties and audio specifications are the same as CA2250.
This amplifier has eight channels capable of driving a maximum of 125W per channel. Dimensions (WxHxD): 482.6 x 88 x 381.8mm. Weight: 7.95kg. All other functional properties and audio specifications are the same as CA2250.
Dante option cards
CDI-CA2, CDI-CA4, and CDI-CA8 are optional Dante network cards for CA series amplifiers. These retrofit option cards allow the amplifier to be directly fed from a Dante audio network. Any card will retrofit any CA series amplifier however it will be limited by the maximum number of channels in the given amplifier. The cards support 16/24/32bit PCM sample sizes, whilst also supporting 44.1/48/88.2/96kHz sample rates. The inputs can be controlled bu Dante Controller and Dante Domain Manger software.
This range of four-channel power amplifiers is intended for commercial and industrial public-address and sound-reinforcement applications where unquestionable long-term reliability is the primary consideration. The three models in the range, offer four channels of 120W, 240W and 400W output; pairs of channels may be operated in bridge mode. The steel 2U chassis has variable-speed, forced-air cooling while the protection circuitry includes clip-limiting and switch-on delay, together with DC, thermal, short-circuit and reactive load protection. The inputs are line-level and electronically balanced, VCA circuitry is provided for remote level control and an optional web monitor card permits monitoring of the amplifier's performance, via a standard Ethernet connection, and if connected to the internet, world-wide, even on a mobile phone.
The amplifiers are designed to deliver their full rated power into loads down to 4 ohms for long periods of time, while bridge mode uses a pair of channels to provide double the normal power into a load of 8 ohms. As well as theatres, leisure centres and other major venues, they are also aimed at applications in airport terminals, railways stations and similar large public spaces.
The substantial front panel, constructed from a cast aluminium facia sandwiched with a steel backing-plate, is dominated by two air-intakes for the variable-speed DC cooling fans. In the centre an inset panel houses LED indicators showing power status, signal presence, signal peak and protection system active for each of the four channels. A large rocker switch turns the amplifier on and off. Two protruding lugs provide protection should the amplifier be placed on the front panel, perhaps during installation.
The rear panel also has two grilles, for air to flow out past the internal heat-sinks. Power is connected by an IEC inlet, which has an adjacent circuit breaker. There are four areas, each for a single channel, each having controls and connectors as follows. The input is a 3-pole, detachable, terminal connectors; Euroblock or 'Pheonix' style. The level control is recessed and screwdriver-operated. A larger 3-pole Euroblock connector provides the connection for remote level control. A switch switches the hi-pass filter in and out of circuit. The controls for channel 2 and channel 4 also have bridge switches, connecting channels 2 and four to channels 1 and 3 respectively. Channels 2 and 3 also have a switch to select the input from channel 1, rather than channels 2 and 3, so that all three could be driven from a single input. Channel four offers the choice of the channel-2 input or the channel-4 input. Two 4-pole Euroblock connectors provide the loudspeaker connections. A blanking panel covers the aperture where the optional VTX-WM1 Web Monitor Card may be fitted.
Inputs: 0.775V RMS, 0dBu, for maximum output, 10k ohms, balanced. Filter: -3dB at 65Hz, 18dB/octave, switched. Maximum VCA attenuation: Better than 90dB. Response: 20Hz - 20kHz, +0/-1dB, with filter bypassed. Distortion: 0.03% THD+N, 1kHz, 1W, 4 ohms load. Noise: Better than 100dB below full output power, 20Hz - 20kHz; 103dB 'A' weighted. Crosstalk: -90dB, 1kHz; -70dB, 10kHz. Power source: 230V AC, +/-10%. Dimensions: 482.6 x 88 x 451(w x h x d)mm, 2U rack mounting, 451 depth including connectors.
Notes: (1) Normal mode, continuous sine wave, 4 ohms load, all channels driven. (2) Two pairs of bridged channels, each with 8 ohm load.
Included accessories: AC power lead, Set of mating screw-terminal connectors, push-in feet, manual.
Optional accessories: The WM-1 surveillance card allows remote monitoring of the amplifier's performance and settings from any computer via a standard web browser. The RL-1 remote control plate fits a standard single-gang UK back-box and gives control of the level of one channel using screened 2-core cable up to 100 metres long. The CXL-100T line driver transformer is suitable for use with one channel of the VTX4120 to provide a 100V or 70V line output, see Cloud 100 Volt Line Transformers.
This may be retro-fitted to Cloud VTX Series power amplifiers, making it possible for a remote user to monitor the performance and settings of the amplifier over a local network or the internet using any personal computer, PDA or smartphone and a normal internet browser application. No dedicated software application or hardware is necessary. The system can also be configured to generate an email report, optionally formatted for SMS text forwarding, if the monitor card detects a fault condition. As well as checking the integrity of the amplifier, the VTX-WM1 generates a test signal for the load impedance test, at one or more user-definable frequencies.
The card simply slots into the pre-prepared aperture on the rear of the amplifier and some internal jumpers are changed. After powering up the amplifier, the installer must log on to the web-server in the amplifier, much in the way that one logs into the configuration page on a router, to set the required IP address. These can either be on the local internal subnet, which will give access to the amplifier by local computers, or fixed IP addresses provided by the user's ISP, thus giving access anywhere from anywhere on the internet. Alternatively remote access may be engineered by forwarding different ports to the different amplifiers, using a local machine as an intermediary with a Remote Terminal Services session or by use of a VPN. The card does not support DHCP. Up to 254 VTZ-WM1 cards may be deployed in one subnet.
Network connection status, the settings of all amplifier rear-panel switches and gain controls, protection circuitry activity, internal temperature, power status and input signal level for each channel are monitored by the card. Fan operation and remote volume control settings (if fitted) are also confirmed. It confirms all user-definable control settings and checks load impedance on demand, or at scheduled times using user-defined frequency. A real-time clock provides for event logging, at a user-definable polling interval, with automatic email or SMS text alert on pre-defined fault conditions. Battery back up provides for messaging should the amplifier power down or even expire, in which case it will e-mail the final settings and events.
A load impedance test is available to check the integrity of each channel's loudspeaker(s) and cabling. This test may be run either manually, initiated from the GUI as required, or automatically at pre-determined times and intervals, usually during periods of non-occupancy. The frequency used for the impedance test is also programmable between 60kHz and 20kHz to allow the installer to select a frequency that is suitable for the different drivers and to avoid speaker resonances, causing inaccurate readings.
The web browser GUI has a set of tabbed pages, which report the details and performance of all the amplifiers on the network. A password protected 'Housekeeping' page is provided which allows site-wide details of the installation to be entered. This page also allows the load impedance test parameters, IP addresses and other system settings to be configured. A real-time clock runs independently of the amplifier power supply and an event log is maintained, which can be inspected as required for investigative purposes in the event of system problems.
Tone generator: 40dB below maximum amplifier output, injected post level-controls, other channels muted. Frequency range: 60Hz - 20kHz, 1/3-octave steps. Signal detector: -30 to +10dBu sensitivity, 20Hz - 20kHz. Ethernet connection: 100 Base T.