Marantz MM7055 Amplifier
The model range of Marantz offers two series of uncompromising cinema solutions. Two tops crown them - a luxurious AV-processor AV8003 and a muscular eight-channel power amplifier MM8003. A more affordable option is presented by AV7005 processor with five-channel MM7055 and dual-channel MM7025 amplifier. The fact that the company divided the gain in this system into two parts seems to be quite logical - most of the home theaters are still built according to the 5.1 configuration, and the pay for off-line channels seems wasteful. In addition, if there is a desire to supplement the home theater to the 7.1 circuit, you will only need to buy a dual-channel MM7025 amplifier.
MM7055 applications are not exhausted at this. External power amplifier can significantly improve the sound of a home theater, originally built on the basis of AV-receiver. In this system the AV-processor plays the role of the AV receiver, and all amplification (or part of it) is transferred to MM7055. It is only necessary to ensure that the receiver is equipped with a multichannel output from the pre-amplification stages.
So why the external gain is better than the multichannel power amplifier integrated into the AV receiver? First of all, by a separate power supply. Without being so tightly bound either by technical, dimensional, or economic constraints, manufacturers tend to equip multi-channel amplifiers with more powerful and high-quality power supplies. Sometimes there are even modular structures in which each channel is equipped with its own power unit. In addition, the removal of power amplifiers in a separate housing eliminates the system from parasitic mutual interference of digital and analog parts and greatly simplifies the organization of component cooling, which is often critical for a power amplifier.
The faceplate of Marantz MM7055 is traditionally made up of three parts. The central section is decorated with a proprietary round indicator with a pleasant bluish backlight. But, instead of the expected signal level indication arrow, there are three LEDs that indicate power on, protection and the activity of the power control. To the right of the indicator there is a small button to turn off its backlight, which can be useful if the device is in a completely darkened cinema hall. In the left part of the facade there is a large Standby button. There is no main power switch for the model. It is understood that in most cases power management will be carried out remotely, for which on the rear wall of the case there are not only connectors for the proprietary control bus, but also standard input and output from the triggers, allowing to interconnect devices of different manufacturers in the same system.
The entire switching arsenal of Marantz MM7055 is strictly structured. The input connectors are mounted at the top of the patch panel, and the screw acoustic terminals are at the bottom. Not only conventional RCA connectors, but professional balanced XLRs, which provide better noise resistance, are provided for connection to a theater processor or AV receiver. The type of input is determined by micro-switches individually for each channel, which can be very useful in complex multicomponent systems. A large power transformer is installed at the rear wall of the body. Cooling of the output stages was originally organized. Directly behind the front panel of ribbed aluminum plates a box is assembled, on which a fan is mounted at one end and the other end rests against the ventilation grille on the side of the body. These plates play the role of coolers for cooling the output stages, made on bipolar pairs of 2SC2922 and 2SA1216 Sanken transistors.
When you add a power amplifier MM7055 to a home theater system with an AV receiver of a very high class, the changes in the nature of the sound were obvious. The power reserve has grown significantly, which made it possible to confidently fulfill dynamic peaks. At the same time, the sound itself was distinguished by the proprietary softness inherent in the two-channel components of Marantz. The ability to find a compromise between the soft and comfortable manner of performance and the spectacular presentation of the most energetic outbursts in the intense scenes of blockbusters stands this device out among competitors. MM7055 made a significant contribution to the formation of a dense surrounding sound canvas with a clear localization of images in space and the highest detailing. It showed itself very well when playing multichannel music tracks, characterized by intensive loading of all five channels - it impressive power-to-weight ratio ensured excellent working out of the smallest nuances even in such a loaded mode.
