Musical Fidelity M6si Integrated Amplifier Review

The new M6si integrated amplifier improves on the outgoing model with more inputs and completely new internals for greatly improved technical and sonic performance

Background
The five-year old M6i integrated amplifier has become widely known as an industry benchmark of great sound, high power and value for money, all delivered in nicely finished, compact package. Since the M6i was launched, the Stone Age has come to meet the Space Age. People are once again interested in phono (The Stone Age!) but also want to hear high-quality computer-based music on their systems, as well (The Space Age!). With these new interested consumers — and our ongoing of our circuit design and SMD PCB layout techniques — the scene is set for a revolution of a proven M6i design concept.

So how did we improve a product that’s package size, power and price were spot on? First we used our exclusive SMD layout techniques to reduce the size of the circuit’s footprint and offer greatly increased flexibility with internal layout.  That allowed us to configure the new M6si as a proper pre-amp with two completely separate and independent monoblock power amps.  To its own separate regulated power supply and discrete monoblock power amps, we added extra input facilities to present a significant advance on the old model.

The new M6si has the following inputs.

• Phono MM/MC
• USB 24bit 96 kHz asynchronous
• CD
• TUNER
• 2 x Aux (1 with HT BYPASS)
• Balanced

Performance
The M6si performs immaculately.  Because of its pre-amp with dual monoblock power amp configuration, both channels of the M6si perform virtually identically, as if you were listening to a pre-amp with separate power amps and rather than a normal integrated amplifier. Distortion is very low, at less than 0.005%.  More tellingly, HF distortion is incredibly low: about 0.006% at 10 kHz and an astonishing 0.007% at 20 kHz. The M6si’s meticulous PCB and circuit design means that HF performance is virtually identical to the LF performance.Channel separation is remarkably consistent.  Most amplifiers (integrated or pre/power) have dramatically worse cross talk with increasing frequency.  The M6si cross talk is outstanding: even at 20 kHz it’s better than 82dB. The M6si’s phono stage is exceptional, with very low distortion at just 0.01%.  It boasts very accurate RIAA equalization, within ± 0.5dB from 20 Hz to 20 kHz), and is accurate to 50 kHz.  The MM noise ratio is an outstanding at 93dB down while the MC stage is,amazingly, about 87dB down.

USB
The 24 bit 96 kHz asynchronous USB input uses exactly the same circuitry and technology as our highly regarded V-Links, resulting in incredibly low noise with virtually no noise or jitter. The M6si’s USB input delivers the finest details from the computer source.

Sound quality
With its exceptional power, the M6si delivers high quality sound that’s effortless and unstressed.  Its stability margins are huge so it will drive any loudspeaker easily.  These are the bedrock upon which the M6si delivers fantastic sounding music.  Because of its pre amp/power amp configuration, it produces wide stable images with an effortless, clear, ungrainy sound quality.  Bottom end is delivered with a vast punch and speed of attack.

All in all the M6si offers true high-end sound quality, an extensive range of useful inputs, a compact package, reliability and a fair price.

The new M6si surpasses the old model in every parameter with extra facilities and flexibility at the same price as the outgoing model. Retail Price: $2,999.
Contact: Randy Bingham | randy@musicalfidelity.com | 480-297-4053