Musical Fidelity M5si Integrated Amplifier (Silver)

I purchased this unit from Safe & Sound HQ in Feb 2023; advertised as ‘open box’. Shipped in original packaging.
The common quote about the M5si is true à it can pretty much power any speaker pairing you can throw at it.
Warm, transparent, and muscular…bass is especially downright concussive.

Features

• 150 watts per channel into 8 ohms, configured internally as two independent monoblocs with a separate preamplifier
• Developed after the flagship Nu-Vista 800 and sharing some of its PCB layout solutions
• Moving magnet phono stage, suitable for cartridges of 1.5mV output or more
• including high-output moving coils
• Asynchronous USB type B input accepting up to 24-bit/96kHz
• Four line-level RCA inputs
• Fixed line-level output plus a variable preamp output for bi-amping or a subwoofer
• 12V trigger in and out
• Universal infrared remote supplied — volume, input select, mute, and transport control for a matching Musical Fidelity CD player
• Distortion below 0.010% and better than 100dB A-weighted signal-to-noise

Specifications

• Type: Stereo
• integrated amplifier
• Power Output: 150 watts per channel into 8 ohms
• THD + Noise: <0.010% typical, 20Hz – 20kHz
• Signal-to-Noise Ratio: >100dB A-weighted
• Frequency Response: +0, −0.1dB, 10Hz – 20kHz
• Output Voltage: 35V RMS, 20Hz – 20kHz; onset of clipping at 99V peak to peak
• Output Current: 62 amps peak to peak — see note below
• Damping Factor: 36 (published in the owner’s manual, absent from the website specification table)
• Output Devices: 2 pairs per channel
• Line Input Impedance: 40k Ω
• Inputs: 4
• x line level RCA; 1 x USB type B (asynchronous, up to 24-bit/96kHz); 1 x MM phono; trigger in
• Phono Type: Moving magnet only. Musical Fidelity states it suits cartridges giving 1.5mV or more, which includes high-output moving coil types. There is no MC setting
• Phono Sensitivity: 3mV nominal (MM)
• Phono Input Impedance: 50k Ω. Note this is Musical Fidelity’s own figure, published consistently on the product page and in the manual. The industry standard for MM loading is 47k Ω, so 50k is non-standard, but the audible consequence is negligible and we have reproduced it as published rather than corrected it
• Phono Signal-to-Noise Ratio: >70dB A-weighted
• Phono RIAA Accuracy: RIAA/IEC within ±0.5dB, 20Hz – 20kHz
• Phono Grounding: 4mm banana post to chassis earth
• Digital Inputs: USB type B only — there is no coaxial or optical input
• Outputs: Trigger out; 1 pair fixed line level RCA; 1 pair variable preamp RCA
• Speaker Outputs: One stereo set on 4mm banana plug / binding posts (one
• left pair, one right pair). There is no A/B speaker switching
• Headphone Output: None
• Remote Control: Supplied. M5s series universal infrared handset covering volume, input selection (CD, USB, PHONO, TUNER, AUX1/HT, AUX2) and mute, plus transport functions for a matching Musical Fidelity CD player. Two LR03/AAA alkaline batteries supplied
• Mains Voltages: 115/230VAC 50/60Hz, factory pre-set; 100VAC 50/60Hz available
• Power Consumption: <0.5W standby; 450 watts maximum
• Supplied Accessories: 10-amp IEC mains lead, remote control, 2 x AAA batteries
• Dimensions (W x H x D): 440 x 100 x 405 mm (17-1/3″ x 4″ x 16″), height including feet, depth including terminals
• Weight: 14.6 kg (32 lb) unpacked; 18.8 kg (41.5 lb) in the shipping carton