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Equipment Review
September 2000

Musical Fidelity A3CR Preamplifier

by Wes Phillips

Reviewers' Choice Logo

"Belongs in the top rank of all the
preamplifiers I have auditioned."

 

 

 

Review Summary
Sound "Immense and encompassing soundstage"; "exhibits the sort of spaciousness that tubes are noted for -- yet its recovery of detail is laser sharp"; phono section is "dead-flat quiet."
Features "Deliberately over-designed to cope with the widest possible range of sources, cables and power amplifiers"; remote control and "first-rate" switchable MC/MM phono stage standard.
Use "A joy to use" -- "once you’ve set it up and turned it on, there’s not much else you need to do."
Value "Doesn’t miss by much" at equaling the performance of costlier preamps, but "the price differential is immense."

Reviewing hi-fi gear is a lot like dating. While you have to acknowledge the potential for disaster every time you consider a new candidate, you generally start off hopeful that the encounter will be, at the very least, amusing. And, each time, you have the thought -- in the back of your mind, if not at the front -- that this time it just might be really special. Serious even. Maybe even the one special item you might want to settle down with.

I originally requested Musical Fidelity’s A3CR preamplifier for review because I thought it might be interesting to play with. Antony Michaelson, Musical Fidelity’s spiritual and temporal director, was making pretty serious claims about it, after all. I figured that, even if it wasn’t as good as he said, it would at least be amusing to discover where he was blowing smoke. But I didn’t end up dallying with the Musical Fidelity A3CR -- I wound up falling for it hard.

God could have made a better berry, but doubtless God never did

Michaelson said it was every bit as good as Musical Fidelity’s limited, and much coveted, Nu-Vista preamplifier. "In fact," he confided, "technically, it’s fractionally better in high-frequency crosstalk, better at HF distortion and it has generally wider bandwidth." He further claimed that the A3CR was as good as the very best preamplifiers made. Sensing my skepticism, Michaelson elaborated, "I know that sounds self-serving, but that’s how it was designed. High performance doesn’t have to cost that much -- if you don’t use bullshit components and bullshit front panels and make obscene profit margins, you can get affordable prices and still have massive performance."

Aha! I pointed out that its 1/4"-thick, anodized-aluminum faceplate and gold-trimmed accents weren’t exactly sackcloth and ashes. Wasn’t this catering to the audio jewelry mentality? "Customers ought to feel good about their purchase. Tactile impressions are important."

The A3CR is a beautiful preamplifier. Its luxurious silver faceplate sports gold-plated accent trim around the large centrally located volume knob (with a resulting "porthole" effect you will either love or hate) and for the full width of the chassis along the bottom. The volume control is nicely textured for that favorable "tactile impression" and an inset red LED makes changes in its position readily apparent from across the room. The power button, tape monitor, and six source buttons (phono, CD, tuner, aux 1, SACD, tape) are metal, buffered by latex pads for a luxe feel (and all of them have red LED indicators, again facilitating remote operation).

The rear panel features right and left main outputs on opposite sides of its span -- attesting to the A3CR’s dual-mono nature. These substantial gold-plated RCA jacks are mounted solidly to the black powder-coated panel. In contrast, the seven pairs of RCA inputs are attached directly to the circuit board. These include a phono input, which is switchable -- a push button to the left of the input jacks switches between MM and MC operation. A chassis ground and an IEC mains socket complete the accommodations.

When I first lifted the preamp’s shipping box, I thought Musical Fidelity must have shipped an A3CR power amp by mistake -- at 28 pounds, the A3CR weighs as much as many power amplifiers. And it is built like a brick outhouse -- a three-seater. In terms of construction quality, it’s the equal of just about anything out there. The chassis is substantial, and the black-powder-finished cover has row after row of ventilating slots cut out of it -- through them, you get tantalizing glimpses of the high-quality components contained within. No matter how high your standards for build quality are, the MF A3CR lives up to them.

Nature always desires what is better

Like the A3CR power amplifier, the A3CR preamplifier uses choke regulation of its power supply. While choke regulation -- or more properly, choke filtration -- was common on tube designs, it fell out of use with the introduction of the transistor, primarily because of fashion and the availability of inexpensive higher-value capacitors.

So why does a power supply need any filtration? Most solid-state components employ a diode-bridge/reservoir-capacitor power supply that charges with quick bursts (120 times a second) as the rectifier diodes switch on and off at the peak and trough of the AC supply. Between pulses, the amplifier cruises off the stored energy in its capacitors. The abrupt transitions between "on" and "off" create "ripple" at 120Hz and its harmonic intervals. Some form of filter is needed to prevent these distortions from compromising the music signal.

Capacitors serve as only a partial filter, according to Michaelson. While the circuit runs off the stored energy in the capacitor in between the rapid charging pulses, during those pulses the component is connected directly to the AC grid by way of its rectifier diodes. As those diodes turn off and on, they introduce "ringing" pulses into the power supply. Adding transformer-like inductors (choke regulation) filters these spuriae almost completely from the power. According to Michaelson, the noise residual left by the choke is close to a pure sine wave, leaving less for the feedback circuit to compensate for.

This gives the A3CR a head start on achieving its vanishingly low levels of distortion, Michaelson claims -- the preamp’s frequency response extends to 100kHz with less deviation than many show at 10kHz. According to him, the preamplifier’s performance outside the audio bandwidth essentially confirms the soundness of the A3CR’s circuit layout.

That circuitry is resident upon a double-sided circuit board laid out to keep signal paths as short as possible. A motorized ALPS pot is controlled by the massive volume control knob on the front panel, as well as the remote. The A3CR is a dual-mono design with sizable toroidal transformers (as well as, of course, separate inductive chokes) mounted on the extreme right and left of the circuit board. Michaelson is quick to point out that even with separate transformers and circuits, some preamplifiers do not demonstrate good channel separation, projection or depth. A poorly designed power supply can introduce sufficient noise and distortion to overcome the benefits offered by physical separation -- just one more area where the choke regulation pays off with a performance benefit, he feels.

The A3CR is unusual in that signal gain is performed before the volume control. This ensures lower noise and distortion -- and also allows MF to design in high overload margins by utilizing high-voltage rails. Michaelson claims most preamplifiers are not, in fact, proper preamplifiers at all. "Most of them are nothing more than a buffer attached to a volume control," he said. "A proper preamplifier should have an input buffer/gain stage, followed by a volume control, followed by a proper output buffer." What’s his point? "The input buffer presents an easy load for the source component and has low distortion and wide bandwidth. It also has low output impedance, which allows it to drive the variable load of the volume control. The output buffer does the same thing, except it has to drive the interconnect cable and properly load the amplifier. This is not an insignificant matter."

Once again, the A3CR’s solution lies in its choke filtration. Because the A3CR utilizes such oversized transformers and massively overrated chokes, Michaelson says, not only is its power supply unusually quiet, but it is also capable of supplying sufficient B+ and B- voltage to allow its circuit to produce 35V output, avoiding overload problems. In addition, he claims, the A3CR’s line-output buffer ensures low distortion, wide bandwidth, excellent damping factor, low output impedance, and immunity to RFI. The A3CR’s high-current output stage "ensures the power amplifier sees all of its output signal," Michaelson says. I’ll bet -- it puts out 3W class A! That’s about as much power as some SET power amps put out.

He's just -- nae better than he shou'd be

There’s no getting around it -- the A3CR is a joy to use. It’s reliable and stable. Once you’ve set it up and turned it on, there’s not much else you need to do. (I’m of the leave-it-on-all-the-time school, although I do unplug my gear from the wall when leaving for vacation.) That makes it even easier to use than the Musical Fidelity Nu-Vista. And how did it compare sonically?

As the owner of the Nu-Vista, a no-holds-barred, limited-edition design, I should be rooting for the more exotic preamplifier -- after all, I have an emotional involvement with it, and an unfavorable comparison could have an effect on my resale price. Yet, I can’t deny what I heard. I just flat-out liked the A3CR better than the Nu-Vista. I think Antony Michaelson heard the same thing, too. He said he tried the comparison himself and rushed the A3CR back to the factory, secure in the knowledge that it "acquitted itself very nicely." Allowing for British understatement (which Michaelson doesn’t typically indulge in), I think he was actually scared by how good the A3CR is.

The Nu-Vista is more neutral-sounding than the A3CR -- to some ears, I suppose it might even totally lack character. Of course, neutrality is supposed to be a good thing when it comes to high-end audio. Fact is, I think most people, myself included, like a little personality in their preamplifiers. Compared to the Nu-Vista, the A3CR seemed a tad warmer and more exciting -- qualities you’d have expected from the tubed preamp. Go figure.

Associated Equipment

Loudspeakers – Dynaudio Contour 1.3 Mk II, Soliloquy 5.0, Thiel CS 7.2.

Amplifiers – Musical Fidelity A3CR power amplifier, Conrad-Johnson Premier Eleven A.

Preamplifiers – Musical Fidelity Nu-Vista, Adcom GFP-750.

Analog – Linn LP12 with Naim Armageddon power supply, Naim Aro tonearm, van den Hul Frog cartridge.

Digital – Musical Fidelity A3CD CD player.

Interconnects – AudioTruth Midnight.

Speaker cables – AudioQuest Dragon.

Accessories – OSAR Selway Audio Racks, Audio Power Industries Power Wedge Ultra 116.

Room treatments – ASC Tube Traps, Slim Jims, and Bass Traps.

One area where they were darn-near indistinguishable was the phono section. Despite its simplicity (no loading options), the A3CR's phono preamp is the real thing. It handled the output of the .65mV van den Hul Frog without a whimper. And without adding any grain or hiss -- this phono section is dead-flat quiet.

And that’s an area where the A3CR has it all over the Nu-Vista. Not that the Nu-Vista is noisy, exactly; it’s just that nuvistors have a distinct steady-state signature. It’s not the same as the thermal hiss from ordinary vacuum tubes. In fact, it’s almost more a texture than a sound, that’s how subtle it is. But the point is, the Nu-Vista has it and the A3CR doesn’t.

Otherwise, the two are hard to choose between. Like the Nu-Vista, the A3CR has an immense and encompassing soundstage. It exhibits the sort of spaciousness that tubes are noted for -- yet, its recovery of detail is laser sharp, a function, I presume, of its low noise floor. Listening to Jon Hassell’s Fascinoma [Water Lily Acoustics WLACS70CD], I was captivated by how wide and deep its reverberant soundscaping really is. All too frequently, a product or system presents a soundstage that resembles a diorama. Depending upon how close or far away the recorded perspective, the soundstage can be any size from shoebox to auditorium -- but the listener always remains aware that he is listening to a box with one wall removed.

The A3CR puts the listener on the other side of that threshold. You’re in the soundstage, and it -- and you -- are life-sized. Or, in the case of a recording like Fascinoma, even bigger than life.

Once you’ve stepped over that threshold, you don’t need to worry about what you might have left back home, either. In terms of dynamic range or frequency response, the A3CR lacks for nothing. Wow, does this thing ever reproduce bass with impact and body! On Scott Robinson’s Melody From the Sky [Arbors Records ARCD 19212], he uses a bass marimba for spectacular tonal color. On many systems, its sound might even go unnoticed. Since the mallets used are quite soft, you don’t hear the transient attack of the struck "keys" -- the sound is deep and diffuse and not at all localized. But it informs the acoustic space within which the music takes place with an almost ghostly moan -- lose the bass marimba and you totally alter the music.

The A3CR manages to illuminate this subtle tonal shading with authority and remarkable control -- it performed even better than the Nu-Vista at separating the deep woody whisper from the sound of the room. This ability to recover hard-to-capture musical sound never ceased to amaze me. Want to really hear the double bass on classic Rudy van Gelder recordings? Listen with the A3CR -- suddenly Leroy Vinegar, Milt Hinton, and Ron Carter are plying life-sized, deep-voiced, percussive instruments. Want to get your breath kicked out of your chest by the bass synth on house music? Play it on the MF.

Dwight Yoakam’s new CD, dwightyoakamacoustic.net [Reprise 47714-2] is a totally different sort of torture test. The CD is a solo recording of Yoakam singing and playing acoustic guitar (with a single electric guitar overdub on "Little Sister"). This disc doesn’t give Yoakam -- or the A3CR -- any place to hide.

Despite the seeming simplicity of the concept, the Musical Fidelity ruthlessly reveals the different acoustic spaces and different microphones used in making this disc (it was recorded in several different studios). dwightyoakamacoustic.net was illuminating because it showed the restraint with which the A3CR highlighted subtle differences. When producer Pete Anderson changed microphones on Yoakam’s vocals, he wasn’t looking for a major change in his voice -- I imagine he went with what he had at each studio. The different tracks should sound pretty similar. And they do. But you’d have to be oblivious to everything but the songs’ lyrics not to notice the changes when listening to the A3CR. Yet, it doesn’t emphasize these details, it merely reports them. The focus is on Yoakam’s aching voice and all of the vocal filigree and technique he employs in putting his songs across. The disc makes a strong argument for his ranking as the purest pure country singer alive.

But of all the world's brave heroes, there's none that can compare ...

Is the A3CR without fault? Of course not. Compared to the $1250 Adcom GFP-750, the Musical Fidelity preamp seems to ever-so-slightly blunt the impact of abrupt transients. And, while the MF has phenomenal bass extension, it doesn’t have the same kind of impact that the Adcom displays. The Adcom certainly isn’t a hard-sounding preamplifier, nor is the A3CR a soft-sounding one. But in a direct comparison, they shade a bit toward those two camps.

And how would I choose between them? Well, they’re actually two very different creatures. The Adcom, with its ability to run as a passive unit, as well as its lack of a phono section, is clearly aimed at a system that does not include phono. The Musical Fidelity A3CR does have a first-rate phono section and, by its deepest design decisions, argues that a preamplifier must provide a high-current output-section to properly control the power amplifier.

But if I had to choose, I’d opt for the Musical Fidelity simply because it was so much fun to listen to -- in other words, much as I respect the Adcom, I love the A3CR. You might feel differently, of course. The fact that I have an emotional attachment to the A3CR probably means it deviates from total neutrality. I can live with that, but that might irritate another listener. If you mistrust any emotional connection to a component, the A3CR probably is not for you.

And, despite Antony Michaelson’s insistence that it was built to match any preamplifier in the world, there’s still something truly special to an Audio Research Reference One, Conrad-Johnson ART, or Mark Levinson No.32 that the A3CR doesn’t quite rival. But it doesn’t miss by much, whereas the price differential is immense.

You better you bet!

The Musical Fidelity A3CR may not be perfect, but it’s hard to find any major fault. Actually, you need to really exert yourself to find its minor flaws. It is spectacularly well built. It is deliberately over-designed to cope with the widest possible range of sources, cables and power amplifiers. Sonically, it belongs in the top rank of all the preamplifiers I have auditioned.

And it’s reasonably priced. At $1495, it cannot be considered cheap, but given the way it’s built and performs, no one could accuse it of being overpriced. But you would have to spend substantially more to better it. The Musical Fidelity A3CR is one of those rare audio products that can be recommended without reservation.

If you’re about to go through the whole preamplifier audition ritual, I might be able to make your life a lot easier. Forget those weekend assignations with one flashy, but ultimately unsatisfying, hottie after another, not to mention those frustrating encounters with the preamp of the month. If you’re ready to make a serious commitment to a reliable, attractive, hardworking overachiever, have I got a preamp for you.

...Wes Phillips
wes@soundstage.com

Musical Fidelity A3CR Preamplifier
Price: $1495 USD.
Warranty:
Two years parts and labor.

Musical Fidelity Ltd.
15/16 Olympic Trading Est, Fulton Road
Wembley, Middx
HA9 OTF
England
Phone: (44) 208 900 2866
Website: www.musicalfidelity.co.uk

US distributor:
Audio Advisor, Inc.
4717A Broadmoor SE
Kenwood, MI 49512
Phone: (800) 942-0220, (616) 656-9585
Fax: (616) 656-9592

Website: www.audioadvisor.com

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