Musical Fidelity M6CD, M6PRE & M6PRX (Hi-Fi+ 76)

You know how it is with Musical Fidelity. Nothing for ages, then along come three at once. The M6i integrated amplifier was an impressive debut for Musical Fidelity’s M6 series. A CD player, pre and power were on the cards. The first was expected, the second two slightly feared. My worry was that Musical Fidelity would simply take the M6i to bits and rebuild it into two separate parts. Actually, it did nothing of the sort. Well, almost.

All the boxes share the same clean lines of the original M6i. It’s very Musical Fidelity, 21st Century style. Black or silver facings with side heatsinks, dimpled brushed alloy pushbuttons and other control surfaces. In other words, understated elegance. The differences – and similarities – stack up pretty quickly though.

The CD player is a fine place to start. No great display wonders from the front panel (it’s a standard blue readout), the key elements are inside the player. Basically, it’s a great DAC with a CD transport attached. Upsampling to 24bit, 192kHz precision (true upsampling says MF… as opposed to fake upsampling?), with coax, optical and USB inputs, digital, analogue and balanced analogue outputs, it’s possible to consider the M6CD as a digital hub as much as a standalone CD player. With the marked downturn in fortunes for CD, this represents a fine way of future-proofing the player, although a slight confusion is there is a second USB input in the preamp.

Fully balanced from front to back, the M6PRE runs in class A mode. This makes it warmer than most solid-state preamps, but is designed to give the best possible performance. There’s a built in MM/MC phono stage, a USB input and a home theatre by-pass circuit for home cinema fans. It looks almost identical to the M6i too, although the logo – made from surgical steel, apparently – differentiates it from the front. No tone controls (of course) and no headphone socket (MF makes its own headphone amp, so perhaps no great surprise there), but otherwise this is a pretty good, pretty standard preamp.

The M6PRX owes more to the company’s titanic, er, Titan power amplifier than it does to the M6i. A fully dual mono affair, the M6PRX sports a dual mono bifilar choke regulated power supply. Those weaned on switch-mode designs might have a head-scratching moment, but choke regulation was a big thing with valve amplifiers back when they could be built big. It makes a profound difference to the performance of a design, as evidenced by the Ongaku-like change to the Pure Sound integrated amplifier when it received a Border Patrol choke-regulated PSU. The downside to choke regulation is its big, heavy and needs an expert to design it. Musical Fidelity has been making choke-regulated power supplies for decades, so it knows what it’s doing here. Which is why the ‘bifilar’ part is key, too. Basically, bifiliar winding allows one side to cancel the other’s magnetic field and noise characteristics. It’s a quiet way of making a very powerful amplifier. If ‘power corrupts’, then the M6PRX chucking out 260 watts per channel and a peak current of 140 amps must make it a very bent amplifier.

The first potential question on a potential customer’s mind must be ‘which USB input do I use?’. From a sound quality perspective, the CD player has the edge, but it’s not a marked and significant improvement. The CD player is best used as a complete digital hub, acting as platform for computer and other digital sources, but it must be tempered by making sure you don’t end up switching to the preamp USB input by mistake. I guess true platform agnostics could use a PC on one USB input and a Mac on the other, but I recommending picking one, and whether you go for convenience or quality, you don’t really sacrifice much of either in the process.

A far easier question is ‘balanced or single-ended’. The answer is balanced. Every time. Unless you are comparing four-figure single-ended interconnects with DJ-chummy £10 a pop XLRs, you will struggle to find any justification to stay with single-ended between CD preamp and power amplifier. That’s not just for noise rejection over hundreds of metres of cable. It sounds better balanced.

Used as a threesome, the M6 package really shines. It’s very much in the Musical Fidelity Power Product mode (as in, it doesn’t sound like the A1, more like the old A370). That means neutral, crisp and dynamic to some, with a slight graininess to the sound that people tend to ignore, or even enjoy. Yes, there will always be someone who gets stuck on this and calls it hard-edged, but realistically this is a very neutral system with the right speakers.