Интегральные усилители — Musical Fidelity M5SI

Musical Fidelity built the M5si as an integrated amplifier with an MM phono stage and an asynchronous USB input. The maker describes it as two independent monoblocs plus a separate preamplifier built on a single circuit board, with a PCB layout that borrows solutions from the Nu-Vista 800, and styles it to match M3s and M6s series products.

Key specs that matter

Power is 150 W per channel into 8 ohm, the output reaches 35 V RMS across 20 Hz to 20 kHz at clipping onset, or 99 V peak to peak, and peak current is 62 A peak to peak. Its damping factor of 36 comes with two output device pairs in every channel. Line inputs have THD plus noise typically under 0.010% from 20 Hz to 20 kHz, noise more than 100 dB below signal A-weighted and 40 kilohm impedance, with frequency response held within +0 and -0.1 dB from 10 Hz to 20 kHz. Dimensions are 440 mm wide, 100 mm high with feet and 405 mm deep with terminals, and the unit weighs 14.6 kg bare or 18.8 kg in its carton.

Engineering and use context

The phono stage takes MM cartridges at 3 mV nominal and suits any cartridge giving 1.5 mV or more, high-output MC designs included. It offers 50 kilohm input impedance, over 70 dB of A-weighted signal to noise and RIAA/IEC accuracy within 0.5 dB over 20 Hz to 20 kHz, and a chassis earth terminal is provided for a record deck. The USB type B input handles asynchronous streams up to 24-bit and 96 kHz and appears on a computer as M5si Integrated 24/96 using the operating system's own driver. Front-panel selectors cover CD, USB, phono, tuner, AUX1/HT and AUX2, and a rear switch sets AUX1 to act as a home-theatre input. Outputs include a constant-level line output that follows the selected source, a volume-controlled preamp output for bi-amping or a subwoofer, and two pairs of speaker terminals. Trigger in and out sockets are fitted as well. Mains setting is 115 or 230 V AC at 50 or 60 Hz, with 100 V AC as an option, and the amplifier draws below 0.5 W on standby and 450 W at most.

Pairing

The fixed line output can feed a headphone amplifier with independent level adjustment, and the variable pre-out lets a powered subwoofer track the front-panel volume setting. An M5s series remote using two AAA cells is supplied.

Alternatives

The Musical Fidelity M6si is the more powerful integrated in the range, with 220 W per channel into 8 ohm and a balanced XLR input.