5- Channel Power Amplifier (2010-18)
Dimensions: 440 x 183 x 384mm
Power output: 140 watts per channel into 8Ω (5 channels)
Frequency response: 8Hz to 100kHz
Total harmonic distortion: less than 0.09%
Damping factor: 100
Gain: 29 dB
Input sensitivity: 1.2V
Signal to noise ratio: 105dB
There are few tachnical issues which are very common in MARANTZ MM7055 that we will discuss here:-
Fault: The power does not switch on. Or, the power switches off immediately after
being switched on.
Solution:- • Check that the power plug is inserted correctly in the wall socket.
• The protective circuit has operated. In this case, remove the power plug from the wall socket, and wait for at least 1 minute before inserting it in the wall socket again.
Fault: There is no sound from the speakers.
Solution: Check the speaker connections and connections to the other devices.
• Alter the input selector to match the input connector (BALANCED or UNBALANCED) of the connected device.
Fault: When the power switches off suddenly during use, the STANDBY indicator flash at approximately 0.1 second intervals and protection indicator flash at approximately 0.5 second intervals.
Solution: The protective circuit has operated. In this case, remove the power plug from the wall socket, re-examine the installation conditions of this unit, and check the speaker cable connections. If the same situation occurs when the power is switched on again, contact the marantz Service Center.
Fault: The power suddenly switches off during use, and the STANDBY indicator and protection indicator flash at approximately 0.5 second intervals.
Solution: • The internal temperature of the unit has increased, causing the protective circuit to operate. Remove the power plug from the wall socket, wait until the temperature of the unit has dropped adequately, and then insert the power plug back into the wall socket.
• Install this unit in a well-ventilated location.
• Use speakers that have the specified impedance.
• If the two core wires of the speaker cables are touching, or if a core wire is out of the terminal causing the core wire to touch the rear panel of this unit, the protective circuit will operate. Remove the power plug from the wall socket, and firmly re-insert the core wire, or fix the terminal before
• Turn the volume down on the amp connected to this unit, and insert the power plug again.