Once I had set up the Musical Fidelity AMS50, what was intended as a short listening experience became a three-hour auditioning period with my reference system, which was composed of the Lawrence Audio Cello speakers, the Concert Fidelity CF-080 preamplifier, and the Concert Fidelity DAC-040. I was in awe and total disbelief as I found myself unwilling to walk away from my listening spot. The Musical Fidelity amp had the magnificent virtues of a pure Class A amp in its purity of tone and overall grainless liquidity, with no sense of solid state artifacts, such as etch or dryness. What distinctly separated it from my solid state mono-blocks and any other solid state amplifier was in three significant sonic attributes.
When I played the entire album Noir (Anzic Records) by Anat Cohen and The Anizic Orchestra, what was very apparent on Ms. Cohen's tenor/alto/soprano/clarinet solos and the backing of the brass section was the voluptuous tone color that I had only experienced with great tube-based amplifiers. The density of the timbres was beautiful and effortlessly rendered.
One of my favorite alto saxophone players is the great Frank Morgan. I had the pleasure of hearing him live on two wonderful occasions in Chicago. The track "Round Midnight" from his album City Nights (HighNotes) showed another striking aspect of the AMS50's performance. From octave to octave, Frank Morgan's alto saxophone playing interwove effortlessly with his excellent trio of jazz stalwarts, yet still gave each player an image of three-dimensionality. The ability to render this type of individual image density/palpability would be closer to what tube lovers are seeking in their systems. Additionally, because of its very low noise floor, the AMS50 allowed micro-details to be easily heard, along with accurate depth and width in its production of the soundstage in the recording.
When I played the legendary album Blue Train (Blue Note Records) by John Coltrane, the AMS50 was able to produce the nuances of his very unique tonality/timbres on his tenor saxophone with great precision. This album was recorded in a small studio setting, with the horn players spaced around one microphone. The AMS50's spatial presentation was so accurate that it was easy to hear each player's position as each walked up to the microphone to take his solo.
One of the great new voices of pop music is the English singer Adele. On her first album, Adele 19 (XL Recordings/Columbia), the song "Daydreams" shows that she has the rare combination of an harmonically rich, pure voice and the ability to share powerful, raw emotion when she delivers the lyrics of her music. Because of its complete transparency, allowing the smallest details to be clearly heard, along with its rich timbres and natural tonality, the AMS50 allowed Adele's vocal performance to deliver all the emotional impact and power of this song.
Finally, I wanted to test the AMS50's ability to handle big dynamics, bass extension and control. One of my favorite rock albums is the Los Lobos classic Kiko (Slash/Warner Brothers), which is extremely well-recorded, with powerful bass riffs and pounding drums. Unlike many tube-based amps that have great tonal beauty but can't control the bottom end of some speakers, the AMS50 produced taut bass with great grip and tonal definition. This is a fast amplifier that offers dynamic impact and authority when the music calls for it. With high-end frequencies, the top end was very silky and smooth, with excellent detail and decay.
Musical Fidelity's AMS50 amplifier is the best-sounding solid state amplifier I have ever heard in my system. It comes the closest to negating the dichotomy between what tubes have to offer - richness in color/tone, warmth, image density/palpability - and what solid state designs have to offer - speed, transparency, accurate leading edges, resolution and low-end control/power. However, there are some concerns if you want the AMS50 to be the heart of your two-channel audio or home theater system. This amplifier is a very handsome-looking beast, but it is quite hefty and large. It will take up a vast amount of floor space and needs to have plenty of clearance for ventilation so that it does not overheat.
Taking into consideration that it runs extremely hot, it will warm up a fairly large-sized room rather quickly. As mentioned before, Class-A power amps also drink AC power like there is no end to the supply, so you could realistically notice an uptick in your power bill if you leave them on all of the time. They also could heat your listening room if you live in a cold-weather climate.Comparison and Competition
Two solid-state amplifiers in the price range of the AMS 50 that would be true competitors are the Pass Labs XA-60.5 mono-blocks
, which retail for $11,000, and the Ayre Acoustics MX-R mono-blocks
, which retail for $18,500. Although the XA-60.5 is comparable to the Musical Fidelity amplifier, the AMS50 clearly surpasses the XA-60.5 with its musical tone, color, timbres, image density/palpability and ultimate dynamic impact.
The Ayre Acoustics MX-R mono-blocks, when compared to the AMS50, offered a drier tonality and lacked the liquidity of the AMS50. The Ayre Acoustics MX-R mono-blocks also produced a soundstage that was much less three-dimensional and shorter in its depth then the AMS50.Conclusion
Musical Fidelity's AMS50 amplifier surpassed what I thought a solid-state amplifier could provide in its ability to offer warm, natural timbres, density of color, holographic imaging, and a flowing seamlessness across the frequency spectrum. It has all the sonic virtues of pure Class A amplification, blending what a great 300B/211/845 tube-based amplifier brings to the music with the transparency/details and power of solid-state. However, due to its hefty build and need for ample floor and ventilation space, its massive heatsinking, and the large amount of heat it produces, the output devices never shut off. Putting aside its physical drawbacks, the Musical Fidelity AMS50 will most definitely evoke a mirage of live music being played in your room. My own Pass Labs XA-60.5 mono-blocks are some of the most highly-regarded solid state amplifiers on the market today. Musical Fidelity, with the AMS50 Amplifier, has entered into this realm of reference-level performance. I highly recommend that you put this amplifier on your audition list if you are looking for an ultimate-level solid state (or tube) power amp.