Summary of the content on the page No. 1
M250
MONOBLOC AMPLIFIER
O PERATE PO W ER
MUSICAL FIDELITY
INSTRUCTIONS FOR USE
Thank you for purchasing the Musical Fidelity M250 monobloc power amplifier.
Used properly and carefully, it should give you many years of outstanding
musical reproduction.
Dust regularly with a soft duster or soft brush, but be careful when using
cleaning or polishing agents - they may harm the surface finish.
If you have any questions about your audio system,
please consult your dealer who is there to help and advi
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SAFETY INFORMATION IMPORTANT! (U.K. only) This unit is supplied in the U.K. with a mains lead fitted with a moulded 13 amp plug. If, for any reason, you need to cut off this plug, please remove the fuse holder and dispose of the plug safely, out of reach of children. It must not be plugged into a mains outlet. The wires in the mains lead supplied with this appliance are coloured in accordance with the following code: Green and yellow..............Earth Blue...............................Neutra
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GENERAL ADVICE INSTALLATION PRECAUTIONS and USER INFORMATION Your new M250 power amplifier is designed and built to provide trouble-free performance, but as with all electronic devices it is necessary to observe a few precautions: Heed all warnings shown on the back of the product. Only connect the M250 amplifier to a mains outlet having the same voltage as marked at the back of the unit. Always ensure that when disconnecting and reconnecting your audio equipment the mains supply is switched
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CONNECTIONS AND FACILITIES O PERATE PO W ER 12 3 MUSICAL FIDELITY Front panel layout 1 OPERATE indicator LED (blue) 2 Power status button (see page 6) 3 POWER-on indicator LED (orange) Back panel layout 3 Speaker output (see page 5) 7 Trigger output (see pages 5 and 6) 4 Speaker output (see page 5) 8 Audio loop output (see page 5) 5 Power switch 9 Audio line input 6 IEC type mains inlet socket 10 Trigger input (see pages 5 and 6) 34 56 SPEAKER OUTPUTS PO W ER OFF CAUTION + DO NOT REMOVE SCREW S
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CONNECTIONS All input, output and power connections Taking the left channel connections, the should be made with the mains power pre-amp’s left output is connected to the- first M250’s LINE INPUT (used for the switched OFF. woofer, or low frequencies), and then the first M250’s LOOP OUTPUT is connect- INPUT CONNECTIONS ed to the LINE INPUT of the second M250 (used for the tweeter, or high fre- quencies). As the M250 is a mono power amplifier, two are required for stereo operation, and further un
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OPERATION OPERATION Trigger Mode Press the POWER rocker switch on the The M250 responds to a “trigger on” con- trol voltage of between 5 and 12 volts posi- rear panel - the orange POWER LED on tive or negative, received via the 3.5mm the front panel will light confirming that the unit is ready for use. TRIGGER IN socket on the rear panel. The first trigger pulse received after apply- ing mains power will turn the amplifier on, Audio Sense Mode and cancel the “audio sense” mode. The M250 is now i
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TROUBLESHOOTING Basic problem-solving with an amplifier is similar to troubleshooting any other electrical or electronic equipment. Always check the most obvious possible causes first. To give you a few ideas of what to look for, check the following: Problem Possible Cause Remedy No power when MAINS Mains plug not inserted Plug in securely POWER switch is operated fully into rear socket No sound Tape monitor function has Switch off tape monitor been selected on the pre- at the pre-amplifier am
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SPECIFICATIONS : M250 Monobloc Amplifier Output voltage, RMS 45 Volts 20Hz to 20kHz peak 127 Volts Power output 250 Watts into 8 Ohms (24dBW) 450 Watts into 4 Ohms Peak-to-peak output current 72 Amps Damping factor 180 Output devices per channel 6 Total Harmonic Distortion + noise 0.006% at 1kHz up to 90% power, into 4 or 8 Ohms Intermodulation distortion 0.004% at 12.5 Watts into 8 Ohms Frequency response 20Hz to 20kHz ±0dB 10Hz to 100kHz +0 / -1.5dB Audio gain 30dB (31.5 times) nominal Input
