The Marantz MM7055 is a five-channel power amplifier positioned within Marantz's dedicated amplification range, sitting above the two-channel MM7025 and offering multi-channel capability for complete home cinema systems. It is designed to partner with AV processors or AV receivers that provide pre-amplifier outputs, delivering dedicated amplification across all five channels of a surround sound system.
Amplification Design
The MM7055 employs current feedback topology with fully discrete amplification throughout all five channels. This approach delivers 140 watts per channel into 8 ohms (20Hz–20kHz, 0.08% THD), with a frequency response extending from 8Hz to 100kHz and a signal-to-noise ratio of 105dB. Each channel features its own dedicated amplification stage with high-grade audio components selected by Marantz's Sound Master during the voicing process.
Power Supply
At the heart of the MM7055 is a large-capacity multiple-secondary EI-core transformer paired with over 65,000µF of custom-designed energy storage capacitance. This substantial power supply architecture ensures consistent current delivery across all five channels during demanding dynamic passages. Heat dissipation is managed by an extruded aluminium thermal tunnel that channels airflow across the output stages.
Connectivity
Each of the five channels provides both balanced XLR and single-ended RCA inputs, with a per-channel selector switch allowing independent input selection. Speaker outputs use gold-plated four-way binding post terminals. System integration features include DC trigger connections (one input, one output), D-Bus remote compatibility (RC-5), a flasher input, and auto power-off standby mode with 0.4W standby consumption.
Build and Finish
The MM7055 features a metal front panel with a low-noise LCD display and digital power meter. The chassis measures 440mm wide, 183mm tall, and 384mm deep, weighing 15.2kg. A detachable power cable is included.
| Channels | 5 |
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| Amplifier Class | Class A/B |
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| Power Output (8 Ohms, 20Hz–20kHz) | 140W per channel |
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| Frequency Response | 8Hz–100kHz (+/- 3dB) |
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| Total Harmonic Distortion | 0.03% (20Hz–20kHz) |
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| Signal to Noise Ratio | 105dB |
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| Damping Factor | 100 |
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| Input Sensitivity (High Level) | 1.2V / 22kΩ |
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| Input Sensitivity (Balanced) | 2.4V / 30kΩ |
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| Balanced Inputs | 5 (XLR) |
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| Unbalanced Inputs | 5 (RCA) |
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| Speaker Terminals | Gold-plated four-way binding posts |
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| Power Transformer | Large capacity EI-core |
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| Power Consumption | 400W |
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| Standby Consumption | 0.4W |
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| Dimensions (W x H x D) | 440 x 183 x 384mm |
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| Weight | 15.2kg |
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