Musical Fidelity Musical Fidelity is a United Kingdom famous manufacturer of Hi-Fi equipment, was founded in 1982. Its design is unique, with many patents, the control CD turntable Jitter (time base error) of unusual skill. Its products include: before and after the merge/amplifier, black plastic wheel, DAC decoder, CD/SACD/DVD-A players. Because their products are not made, in domestic or factory maintenance, Yu-audio provides maintenance services. Includes: MUSICAL FIDELITY music fax class amplifier, integrated amplifier, CD player. Model: M3, E70, A300,A1008, A3.2, A5.5, V8 etc.A3vservice manual download site
Musical Fidelity music fax M3 power amplifier service examplesA3vservice manual download site
A3vservice manual download site
Symptoms: press the AC power switch and power indicator light is on, can hear the relay sucks and shuts and amplifier directs a minute later off and relay also let go. Power light is flashing.A3vservice manual download site
Analysis: this machine is level after the merge, separate power supplies, power out three interfaces, flanked by power the amplifier left and right channel separately, for the control circuit power. The root interface in the Centre the 9 volts of AC dual-71 v, into the amplifier rectified and filtered to get 12 volts plus or minus 100 Volts, respectively, as the control circuit and preamp power supply. This power structure different from other amplifiers. Notes amplified after each device in the shape of a square transformer,A3vservice manual download site
A3vservice manual download site
But this is not a transformer, but music unique to fax and choke coil, used to clean a power supply in power supply circuits enhance the sound quality of the effect.A3vservice manual download site
Maintenance: after three power cords connected, measure the voltage voltage measured AC 9 volt is actually 7 volts, double 71 in fact, 16 Volt, abnormality, immediately shut down. Open the power box cover, two large transformers and a small transformer, see appearance is no exception, clean up the circuit to, 220-volt AC power coming in through small AC switch supply transformer and main relay, 9 VAC for a delay element on the small circuit board to start main relay, main relay to pull-in description circuit board without problems,

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