Усилители мощности стерео — Musical Fidelity M8S-500S

The M8s-500s is a stereo power amplifier with fully balanced circuitry from the British maker Musical Fidelity, part of its M8 series. Each channel is built from a pair of high-current power amplifier sections connected in bridged mono configuration, and the maker presents it as the visual and technical partner of the M8 preamplifier, so the two form a complete amplification system.

Key specs that matter

Output is 500 W per channel into 8 ohm, which the maker also expresses as 27 dBW, rising to 870 W per channel into 4 ohm. THD plus noise is typically under 0.007% across 20 Hz to 20 kHz, with A-weighted noise more than 120 dB down. Frequency response is stated as +0, -1 dB from 10 Hz to 80 kHz. The chassis measures 440 x 160 x 460 mm and weighs 29 kg unpacked or 34.5 kg packed.

Engineering and use context

Balanced operation extends from input to output, with the bridged pair of amplifier sections in each channel sharing the load. Power comes from dual Super Silent toroidal transformers. The inputs are one RCA line level socket and one balanced XLR line level socket, and each has a matching loop output in the same format, which lets the incoming signal continue to a second amplifier such as another M8s-500s in the same system. A 3.5 mm mono trigger input accepts from 4.5 to 15 V DC, and a 3.5 mm trigger output supplies 12 V DC, allowing the amplifier to switch on and off with a preamplifier or processor and to pass that command down a chain. The heavy chassis shares the 440 mm width of the M8 preamplifier, so the two units have an identical footprint on a rack. The loop outputs and trigger chain together make multi-amplifier setups straightforward to wire.

Pairing

The M8sPRE is the matching control unit in the same series, a balanced Class A control unit with XLR and RCA pre outputs, so a balanced link between the two keeps the signal path balanced end to end. Its switchable MM/MC phono stage covers a turntable, and its home theatre bypass inputs allow the M8s-500s to drive the front speakers of a surround system as well. The high power rating and the large reserve into low loads point to speakers with low impedance or modest efficiency.

Alternatives

Musical Fidelity also makes the M6x 250.4/2, a class A/B design rated at 180 W into 8 ohm in bridged two-channel mode, which can also run as a four-channel unit.