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Arcam Alpha 7R Amplifier Repair (With Audio Tutorial)



Published
Fault
Amplifier in protection mode power LED Amber.

Dry solder joints on the pins of the output Mosfets.(IRF540N)
Connections re-flowed fixing the protection mode issue.

Dry solder joints on the following also re-flowed.

Input RCA sockets.
Speaker Terminals
Power Socket
Headphones socket
Bass, Treble, Balance 7 volume controls.
Selection switches Tape, Direct and SP2.

Input selection switch removed and taken apart.
Wafer contacts cleaned with a fibre glass pencil to remove oxidization.
https://uk.rs-online.com/web/p/abrasive-pencils/1835226

Switch re-assembled and fitted.

Speaker protection relay as shown in the video replaced to avoid any issue with intermittent sound loss or distortion at low volume.

User controls cleaned with De-Oxit to ensure noise free operation.

Bias for each channel set to 3.2 millivolts.

Service Manual https://www.hifiengine.com/manual_library/arcam/alpha-7.shtml

Amplifier fully tested working correctly.
Category
Audio
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