The most powerful integrated amplifier of the English company Musical Fidelity. Dual mono design with separate power transformers, rectifiers and smoothing filters for left and right channels. Record output power, and in the M6500i it is declared 2 x 500 W on an eight-ohm load. Six complementary pairs of transistors with a permissible collector current of 15 A are installed in each channel. Effective heat removal is ensured by huge radiators, which are the side walls of the case. The front panel is turned from an aluminum plate with a thickness of 12 mm.
The device is designed for connection to five sources, including one balanced. With the switch on the back panel, the AUX socket can be reassigned to the HT (Home Theater) input, in which case the volume control is carried out in an external device - processor, AV receiver, etc. Tape/monitor recording control and preamplifier output are provided, which can be useful for system expansion, for example, bi-amping organization.
Own volume control: multi-turn electronic with a step of 0.5 dB. The level change is very smooth, it is convenient to control it on the 7-segment LED display, the window of which is located directly above the large volume knob.
The amplifier is mounted on a prefabricated chassis with a symmetrical arrangement of channels. Near the front wall in the center is a pair of large Noratel (Norway) tori with a capacity of about a kilowatt each. To suppress vibrations, the central hole of the "bagels" is filled with a compound. The smoothing filter in the power circuit of each channel consists of four capacitors 6800 μF x 100 V (total capacity 54400 μF).
The output stage is built on complementary Sanken STD03P / N transistors with a power of 160 W, six pieces in parallel in each arm. They are installed on the heat sinks, which are also the side walls of the case. The wiring is made with a cable of a large section, in the event of abnormal situations, the output to the acoustics is interrupted by powerful relay contacts in the protection system.
The input switch is electronic, on the Sanyo LC78211 microcircuit.

Specifications
Output power (8 Ohms): 2 x 500 W
Maximum output voltage (RMS, 20 Hz - 20 kHz): 64 V
Peak output current: 100 A
Damping factor: 250
Reproducible frequency range (+ 0 / -0.1 dB): 10 – 20000 Hz
Distortion coefficient (20 Hz -20 kHz); 0.01%
Signal to noise ratio: & gt; -100 dBA
Input resistance: 38 kΩ
The maximum power consumption is 2000 W
Dimensions: 440 x 160 x 460 mm
Weight: 28 kg.