MPA SERIES MIXER-AMPLIFIER Installation and User Guide
Contents Safety Information......................................... 4 Safety Notes regarding Installation......................... 4 Conformities................................................... 4 Safety Considerations and Information................. 4 Caution - High Voltages............................................. 4 Caution - Mains Fuse................................................. 4 Caution - Servicing..................................................... 4 General Description..................
Safety Information Safety Considerations and Information Safety Notes regarding Installation The unit must be earthed. Ensure that the mains power supply provides an effective earth connection using a threewire termination. •• Do not expose the unit to water or moisture. •• Do not expose the unit to naked flames. •• Do not block or restrict any air vent. •• Do not operate the unit in ambient temperatures above 35OC. •• Do not touch any part or terminal carrying the hazardous live symbol ( the unit.
General Description The Cloud MPA Series is a range of mixer-amplifiers with applications in Licensed, Retail, Leisure and similar venues. Three models are available to suit different output power requirements (60, 120 or 240 watts); otherwise all models have identical facilities. The mixer-amplifiers have inputs for six stereo line signals and four microphone signals. Front panel controls are provided for music source selection, music level and microphone levels.
5 6 7 7 4 MAINS O I 5 L6 L5 L2 7 9 2 L1 fig.
Music Inputs Music Level Control The unit has six stereo line inputs; these inputs are suitable for most music sources such as compact disc players, tape players, satellite receivers and the like. Each stereo input is summed internally to mono. All inputs are unbalanced and use RCA phono sockets. The input impedance is 47k ohm. Line 6 input can be configured to have priority over any other music source, see Music Priority, page 8.
Music Equalisation Microphone Access Input One set of independent bass and treble controls is provided for the music signals. These preset controls are located on the rear panel below the line input sockets. The treble control has a range of ±10 dB at 10 kHz and the bass control has a range of ±10 dB at 50 Hz. Mic input 1 is equipped with an external access control input; this is a 2-pin 5 mm-pitch screw terminal connector adjacent to the Mic input 1 connector.
ideally by the people who will normally make them. The Mic EQ should be adjusted if necessary to maximise voice clarity. Microphone Priority MPA Series mixer-amplifiers provide two separate microphone priority functions. One of these enables the microphones to have priority over music, the other allows Mic 1 to have priority over the other microphones. Microphone over music priority Fully automatic voice operated priority (VOX function) is available for the microphone signals.
Bose® Equalisation Modules High pass filter A high pass filter is provided to protect speakers, transformers etc. from the effects of low frequency signals. The filter is enabled by the internal jumper J2 (see fig.7). The filter reduces the output level of frequencies below 65 Hz, and ideally should be used if the line output transformer is in circuit. Music Mute (Fire Alarm Interface) MPA Series amplifiers are compatible with single channel Bose® Series II equalisation modules.
General Notes Earthing Multi-zone Applications When several mains powered units are connected together via their signal cables, there is a risk of one or more earth loops which may cause an audible hum on the system even with the gain controls set to minimum. Where the sound system specification calls for separate control in several zones, MPA Series amplifiers can be used in multiples.
Technical Specifications Line Inputs Frequency response Low-Z output High voltage outputs +0 dB/-1 dB from 20 Hz – 20 kHz (65 Hz filter switched out) +0 dB/-2 dB from 20 Hz – 20 kHz (65 Hz filter switched out) Distortion Low-Z output High voltage outputs <0.03% @ 1 kHz, 1 dB below full power (80 kHz bandwidth) <0.04% @ 1 kHz, 1 dB below full power (80 kHz bandwidth) Sensitivity 195 mV (-12 dBu) to 2.
Location of internal jumpers, etc. J1 J2 MPA SERIES: MAIN PCB. TOP VIEW. ONLY PRIMARY COMPONENTS SHOWN. J3 BOSE EQ CARD SOCKET J4 CHIME VOLUME CONTROL J6 J7 CON8 J8 FAN J9 J10 J13 (under sub-board) J5A & J5B NOT TO SCALE REAR OF AMPLIFIER J12 J11 (below ribbon cable) J14 fig.
Bose® is a registered trademark of The Bose Corporation. In the interest of continuing improvements Cloud Electronics Limited reserves the right to alter specifications without prior notice. 14 MPA Series User Manual v1.
Cloud Electronics Limited 140 Staniforth Road Sheffield S9 3HF England Tel: +44 (0)114 244 7051 Fax: +44 (0)114 242 5462 email: info@cloud.co.uk web: www.cloud.co.
