26 September, 2010

Review: Muiscal Fidelity A100-X

Review: Muiscal Fidelity A100-X (and Revel Ultima Gem I)

Part I.
The MF A100-X is a close cousin of my favorite integrated amp, the iconic A1 designed by Tim Paravicini (EAR). I quote myself:

Musical Fidelity A1 and A100-X and variants
From a pure sonic viewpoint, personally I think the A1 (and its closely related siblings A1-x, A1-S, A2 etc) as well as the higher powered A-100-X are the best integrated amps ever. Their unique look is entrancing. But they run alarmingly hot. One must have adequate ventilation. They are musically so wholesome that one wonders why a tube amp is needed. They even have better bass! Power is limited but if your space is not too big it's enough. In this respect the A-100-X is superior, with enough power to drive a good speaker even in a larger LR (info here). If the A1 were not so good, they would not be introducing a new version so many years later (though its power rating is closer to the A-100-X)! I haven't heard the new one. I am using an A1-S in my bedroom, which is air-conditioned in the summer, but it's in winter that the amp is comforting!!! It's a great match with my Audio Physic Step. Here is a must-read site. MF is NOT a brand that I like too much but, hey, the A1 was designed by none other than the great Tim Paravicini, now founder of EAR. If you know the excellence of EAR gears, you'd like this one. The MC/MM phonostage is excellent.
(click for full overview).

The web does not have much info on the A100-X. This little bit is interesting:

Product Info
(from cached file) The Musical Fidelity A100 is a strongly biased into Class A (roughly 93% of music is in Class A), the A100 benefits from the sonic advantages of Class A operation, without the drawbacks of immense heat and vast power consumption of pure Class A. It is a low feedback design with passive preamp, phono and RIAA stages, and a sophisticated power supply.

Info on Italian site

Serendipity, A Gem!
A few weeks ago after yumcha I went into 影音寄賣 (Central) and immediately spotted a mint-condition A 100-X quietly sitting in a corner. My heart literally fluttered. As the price was reasonable and condition excellent, I bought it without hesitation. For testing, 榮哥 hooked it up to a pair of old Revel Ultima Gem I. Before hooking up, he was worried the sound may not be too good, as the 50 wpc on hand, though twice that of A1, is really quite limited. But we were testing only for function.

When the music played we were quite pleasantly surprised by the absolute rightness of it. The 2010 AV Show CD was rendered as well as I have heard anywhere. Most impressive was the quiet background, from which pristine sound emerged. It was so good that for twenty minutes it literally stopped everyone in his track.

I have always liked Revel loudspeakers, particularly the Ultima's and Salon's. I'd refer you to JA's review in Stereophile. I'd buy this pair downright if it were not for the dark wood finish, which is not to my taste for this particular styling.

Back Home
I tested the A100-X in my living room with the following gears:

Digital: Quad 99 CD-P
Analogue: Clearaudio Concept/Ortofon MC3000
Speakers: Usher X-708; KEF LS3/5A; ATC SCM7

A note on the CD player which I just brought back from SZ. This is a wonderfully natural player that is woefully under-rated. And I don't usually like oversampling technology. This shows with every kind of technology, some people do it right, and some don't. Mine is the original version with Philips CDM-Pro 2 laser (as reviewed by KK).The later version CD-P2 is basically the same player with a different laser mechanism (as reviewed by Stereophile).

While not quite matching the refinement of the Revel heard at the shop, it partnered the Usher X-708 extremely well, delivering a lively and dynamic sound. With the less efficient ATC SCM7 sound turned a little stressful at high volume. My KEF LS3/5A did surprisingly well, even with a Bruckner symphony. With simpler material, like RR's Rameau, sound is truly sophisticated. Although 50 wpc is only nominally more powerful than the A1's 25 wpc, subjectively it seemed to have significantly more power.

Just to satisfy my curiosity I gave the MC phono section the ultimate challenge by using my Clearaudio Concept setup. The Ortofon MC-3000 has a very low output of 0.13, but the A100-X handled it with aplomb. It was quiet and good sounding and, although lacking a little necessarily in ultimate dynamics, everything moved with good PRaT. A marvelous phonstage!

At the start of the article, the "Product Info" was from a previous MF website page used by some seller. MF doesn't have info on the A100 anymore. I was much intrigued by the statement "... It is a low feedback design with passive preamp..." and shall test this out by using a preamp in Part II. Perhaps there's really no preamp section, as the usual volume pot noise prevalent on the A1, which some attribute to DC (see must-read site cited previously), is completely absent.


  1. AnonymousJuly 26, 2015

    I bought one partly based on your review, and it really does sound nice. I'm not a solid state fan, but if it all sounded this good....

    System context: Musical Fidelity CR3 DAC, JBL L1, music off computer using Foobar2000 and Mathaudio Room EQ.