Интегральные усилители — Musical Fidelity M3SI

The M3si is a Musical Fidelity integrated amplifier that pairs a line and phono preamplifier with a USB digital input. Compared with the earlier M3 it gains two new inputs, a phono section so a record deck can be connected directly, and an asynchronous USB port for playback from a computer, and it is styled to match other M3 and M3s series components.

Key specs that matter

Output is 85 W per channel into 8 ohm, and the power section reaches 27 V RMS across 20 Hz to 20 kHz at the onset of clipping, or 76 V peak to peak, with 25 A peak to peak of current and a damping factor of 36. Line inputs measure below 0.014% THD plus noise from 20 Hz to 20 kHz, keep A-weighted noise more than 98 dB down and present a 40 kilohm load, while response stays within +0 and -0.1 dB between 10 Hz and 20 kHz. The case is 440 mm wide, 100 mm tall with feet and 400 mm deep with terminals, and weighs 9.2 kg unpacked, 13 kg packed. According to the maker, the design stays stable into any load and can drive virtually any suitable loudspeaker.

Engineering and use context

The phono input is designed for MM cartridges at 3 mV nominal sensitivity and is suitable for any cartridge delivering 1.5 mV or more, including high-output MC types. It has a 50 kilohm input impedance, A-weighted noise more than 70 dB down and RIAA/IEC accuracy within 1 dB over 20 Hz to 20 kHz, and a 4 mm banana post connects the turntable ground lead to chassis earth. The USB input uses a type B socket and takes streams up to 24-bit and 96 kHz in asynchronous mode. Four pairs of RCA line inputs sit alongside, and on the back there are also fixed line outputs, pre-outs meant for jobs like bi-amping, and a doubled set of loudspeaker posts accepting 4 mm plugs. Each channel runs a single pair of output devices. Mains input is factory preset to 115 or 230 V AC at 50 or 60 Hz, with 100 V AC as an alternative, and consumption is under 0.5 W in standby and up to 320 W at most.

Pairing

Any turntable carrying an MM cartridge links to the phono socket without extra gain, and a laptop running as a music server feeds the USB port without a separate DAC. Supplied accessories are an M3s series handset, its pair of AAA batteries and a 10 A IEC mains lead.

Alternatives

The Musical Fidelity M5si steps up within the M series of integrated amplifiers to 150 W per channel into 8 ohm in a 14.6 kg chassis.