The next album I listened to was Rush's Moving Pictures (Mercury Records), which I downloaded from HD Tracks and is a 96kHz/24 bit FLAC audio file. Playback was via PS Audio's PerfectWave DAC's network bridge, review forthcoming. I was unable to use the DAC in the Cary 303T as I have not yet replaced the Sonicweld USB to SPDIF converter that I had to send back to the manufacturer. I have long been a fan of Alex Lifeson's guitar work and was looking forward to listening to this high resolution version of an old favorite. I was immediately greeted by familiar sounds, everything sounded as it should, the vocals and instruments were as they should be, the soundstage was deep and better defined than on the CD version.
However, I was missing some of the immediacy I have come to expect from Chesky's higher resolution audio files. I tried playing the same tracks through my McIntosh MC501 amplifiers (which at $11,000 a pair are over three times the price of the Musical Fidelity amplifier) and found a greater sense of immediacy to be the most notable difference between the two amplifiers. The immediacy was particularly noticeable with Lifeson's electric guitar.
Wanting to stick with some high-energy rock I played Godsmack's "Battalla de los Tambores" from their Changes DVD (Coming Home Studios). I played this track through both the MartinLogan and Acoustic Zen speakers. This track features dueling drums, which gave the Musical Fidelity ample opportunity to show off its macro dynamic capabilities. At any sane listening level, and even a bit beyond, the amplifier never strained. There were no signs of compression or loss of control. The drums remained tight and tuneful with well-defined notes and decay. When I listened to this track I was already more than an hour into that day's listening session and the amplifier was very warm afterwards. It was not too hot to touch but I would be sure to place it in a well-ventilated space.
Lastly, I played a piece that tests both macro and micro dynamics and that has been in heavy rotation at my house: Carl Orff's Carmina Burana (Telarc SACD). The tracks Fortuna Imperatix Mundi "O Fortuna" and "Fortune plango vulnera" are complex pieces that test both sheer dynamics and detail of a system. The soundstage was appropriately immense through the M6 PEX. When compared to the NuForce Ref9 V3 SE ($5,000 per pair), the Musical Fidelity had more weight and a larger soundstage. Bass control was close between the units with a slight nod to the Musical Fidelity and the NuForce edged ahead in the area of resolution.
Competition and Comparison
The NuForce Ref 9 V3 Special Edition and the Cambridge Audio Azur 840 come to mind as potential options. I have not heard the Cambridge amplifier but the NuForce amplifier retrieves slightly more detail but also comes with a price premium of approximately 50 percent. For more on amplifiers in general, visit Home Theater Review's Amplifier page.
The M6 PRX is missing two features I would like to see on an amplifier: a 12-volt trigger and good binding posts. The trigger allows for easier integration into a system by automating turning the amplifier on and off. This is especially helpful when the unit is packed away in a hard to access cabinet. The binding posts did not facilitate all types of speaker cables and their build quality did match that of the rest of the amplifier.
It was hard to find fault with the amplifier's sonic performance. It is not the last word in detail or power but within the boundaries of what it does, it does them extremely well. The amplifier has an extremely low noise floor, which would normally mean an exceptional amount of detail would be discernible due to the absence of noise. While the M6 PRX exercised great control over the musical notes, without a sign of bloat or muddiness, this control is also the amplifier's greatest sonic pitfall, although this is a matter of personal taste. Audio components must walk a fine line with damping; too little and the music will be ill defined, too much and some of the nuances will be lost. For my taste, the M6 PRX, is slightly on the too much side of the damping. To the amplifier's credit I would rather have the music clean, controlled and slightly over-damped rather than the alternative.
The Musical Fidelity M6 lineup, and in particular the M6 PRX reviewed here sits in a critical spot in the audiophile world. At $3,500 it is not an inexpensive piece where second-rate sonic performances are tolerated, nor is it a pinnacle product expected to have world class build quality and sonic performance. Placing a product in this position requires some tough choices and I think Musical Fidelity made some good decisions with the M6 PRX. While the amplifier is attractive and reasonably well made, one will not confuse this with a Jeff Rowland component or even one from Musical Fidelity's similarly styled higher end products. Money is not wasted on superlative build quality; rather the money is spent on the components that comprise the amplifier and achieving a certain level of sonic performance. This is consistent with the decision to have the amplifier designed by the acclaimed designers in Britain and then built in Taiwan. If you treat your products with normal care and do not require eye candy, this should not pose any problems.
If you are looking to spend $5,000 or less on an amplifier the M6
PRX is very much worth taking a listen to. One would never confuse the
sound of this amplifier with one of a tube amplifier but it does have
some similar sonic qualities that I enjoyed. The M6 PRX had a grain
free easy presentation that made long listening sessions enjoyable. It
also had some of the better qualities of s solid-state amplifier such
as a low noise floor, good bass control and impressive dynamics.
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