Усилители мощности стерео — Musical Fidelity M6X 250.4/2

The M6x 250.4/2 from the British company Musical Fidelity is a class A/B power amplifier that works either as a four-channel unit or, bridged, as a two-channel amplifier. The maker positions it for expanding a home theatre system, whether to drive the main left and right speakers in bridged mode or to add channels to a 5.1 or 7.1 AV receiver, taking a setup from 5.1 to 7.1 or from 7.1 to 11.1. The same chassis therefore covers both a stereo role and a multichannel role, selected by the operating mode.

Key specs that matter

In bridged two-channel mode the rating is 180 W into 8 ohm and 250 W into 4 ohm, with 400 W peak into 2 ohm. In four-channel mode each channel delivers 90 W into 8 ohm and 175 W into 4 ohm, with 250 W peak into 2 ohm. THD plus noise is 0.003% at 100 W, while noise is quoted at 105 dB below a 200 W signal at 1 kHz. Frequency response runs from 20 Hz to 20 kHz within 0.5 dB, and the damping factor is 80. Input sensitivity is 700 mV on RCA and 1.4 V on XLR. The chassis measures 435 x 110 x 435 mm and weighs 21.5 kg unpacked, about 24 kg in its box.

Engineering and use context

Cooling is passive, relying on heat sinks with no fan or other active cooling element, so the amplifier runs silently. The front is an aluminium extrusion finished in black or silver. The rear carries four gold-plated RCA line inputs, four balanced XLR line inputs and four RCA through outputs, which pass the incoming signal on to another amplifier. Four pairs of gold-plated speaker terminals accept bare wire as well as banana or spade connectors, one pair per amplifier channel. Through the trigger in and out sockets, an AV receiver or processor can power the amplifier up and down along with the rest of the system, which the maker lists as part of its home theatre integration. Mains voltage is internally switchable between 230 V and 115 V, with a 100 V version optional. Maximum consumption is 1000 W, and standby draw stays under 0.5 W.

Pairing

The through outputs make it simple to chain a second M6x 250.4/2 for more channels, and the balanced inputs suit processors and preamplifiers with XLR outputs. In four-channel mode the unit can power surround and height speakers, while bridged operation turns it into a stereo amplifier for a front pair of low-impedance speakers. A receiver with pre outputs keeps its own amplification for the remaining channels, so the M6x takes over only the channels it is connected to.

Alternatives

The Musical Fidelity M8s-500s is a balanced two-channel amplifier of the M8 series, rated at 500 W per channel into 8 ohm, in a 440 x 160 x 460 mm chassis weighing 29 kg.