Musical Fidelity AMS Primo line preamplifier Page 2

The overall sound was harmonically rich without turning overripe. Attacks were surprisingly lightning-fast and ultraclean for an all-tube product. But sustain was where the magic lived: sounds just sailed generously on and on, their full harmonic envelope unfurled, slowly decaying into the sunset of background ambience before finally, cleanly disappearing altogether. Musical events effortlessly appeared, lingered, and dissolved, one after the other, meeting along the way no grain, glaze, or grit-induced resistance.

No syrup
I couldn't characterize the Primo's sound as "warm" or "tubey," nor were there any obvious lumps in its frequency response. The bass foundation—even amplified rock bass—was well extended and defined, muscular yet harmonically complete. The spatial presentation was wraparound large, with well-focused images of generous size on a very wide soundstage that extended beyond the outside edges of the speakers and seemed to curl toward me in a gentle U-shape.

In a listening room as small as mine, the pictures painted were almost too big, but that's no criticism of the Primo. In a much bigger space, the same spatial presentation would be ideal. However, even larger than life, as it sounded in my room, the pictures were more than pleasing.

As I write, the Sooloos has Swum to a Pat Martino tribute to Wes Montgomery (CD, Blue Note 11226), and Martino's big, hollow-bodied electric guitar is taking up most of the space between the speakers. The guitar sounds warm and full—certainly much more so than it does through the darTZeel—yet with enough speed and definition to delineate the attack of the fingerpicked strings. The piano, occupying the same center space, is wrapped far tighter, cleaner and appropriately more percussive, producing in me a feeling of confidence that Martino's big, warm guitar is sounding as it should, and that what I'm hearing is not the product of a warm, sloppy—in a word, distorted—tube midband. The Primo has tube flow, but not the colorations often found in tube front ends. If you didn't already know this about the Primo, it's doubtful you'd think you were listening to tubes.

I could be enthralled by the Primo's graceful, nuanced reproduction of a well-recorded piano concerto, then switch to Bernie Grundman's stunningly mastered 180gm-vinyl reissue of Nirvana's In Utero (LP, DGC/ORG 033), and still feel as if I was getting it all—from Kurt Cobain's barbed-wire Fender Mustang guitar to the bottom-end drive of Krist Novoselic's thickly textured bass, to drummer Dave Grohl's warm, hard-pounding tom and edgier snare. On "Heart-Shaped Box," Cobain's voice has the appropriate sibilant edge and, behind it, the warm envelope of the recording space so carefully captured by Steve Albini. While a solid-state front end might provide a bit more bottom-end drive and extension, no grunge rocker listening to In Utero through the Primo will feel the need for more of anything while luxuriating in the generous fullness of its solid, three-dimensional picture.

The Primo didn't pour syrup over everything, as some tube preamps do. If anything, its midrange was on the light, buoyant, effervescent side, and its sound could push too much midrange information to the front of the stage, which made me want to turn down the volume a bit (though that might have been a side effect of my small room). Or perhaps it would be a better match with a loudspeaker less generous in the midrange than the Wilson Audio MAXX 3s.

For instance, when I played—at what I consider an appropriate level—Liszt's Piano Concerto 1, with pianist Byron Janis accompanied by Kiril Kondrashin and the Moscow Philharmonic (CD, Mercury Living Presence 432 002-2), the images were too big and crowded the stage. In addition, the piano sounded a bit milky and tonally ill defined. Dropping the overall level clarified the picture, widened the stage, shrank the piano to the appropriate size, and restored the proper harmonic and percussive balance. It also moved me back about 20 rows, but that's where the Primo made this recording sound most appropriate.

Going back to the darTZeel NHB-18NS produced a mixed bag of wholly expected sonic sensations: a more precise if less exuberant picture with smaller, more precisely defined images of the individual source and greater three-dimensional space, particularly in terms of depth; tighter but not necessarily deeper bass; somewhat truncated, less fully fleshed out harmonic structures; shorter sustain; more precise and crystalline attack; greater transparency and blackness between notes; and a more clinical, somewhat drabber, yet more detailed sound overall, accompanied by diminished sense of musical flow. In short: two completely different, equally valid sounds, each with its own attractions and minor shortcomings.

To some audiophiles, a preamplifier should be a "straight wire with gain." To others it acts more like a mastering engineer, putting the final subtle touches on the raw material it's fed. Some audiophiles in search of a mythical audio grail use an unbuffered passive volume pot to attenuate the level and leave it at that—never mind how, depending on attenuation level, that will affect the signal.

Most of us aim for a device that conveniently and flexibly routes and processes the signal while altering that signal as little as possible, even as we acknowledge that, inevitably, such a device will affect to some degree, however slight, the music's transparency, dynamics, and frequency response.

But the better a preamp is, the less it will impose its sonic will on any signal it's fed, particularly in terms of noise, frequency response, and linearity. I've never heard one that's 100% transparent, though some come closer than others—if that's what you want. If, on the other hand, you want to dramatically shift your system's sound in one direction or another, there are many other preamps that can do that.

Musical Fidelity's AMS Primo is among the most transparent tube preamplifiers I've heard in terms of transient speed, frequency extension, subjectively flat response, low audible distortion, and low noise floor. And, unlike some tube gear, it was not about adding to the signal some dark, lush beauty or golden glow. It did, however, impart to signals from solid-state sources a particularly pleasing and lively quality that produced great drive, musical flow, and an appropriately rich harmonic palette. For many listeners, all of those will be most welcome additions to their systems' sound—particularly if, as happened with me, the Primo calls no attention to itself by either committing obvious sonic sins or sinning by omission.

The biggest problem I had with the Primo was that when it drove Musical Fidelity's own Titan, I didn't feel the volume control was sensitive enough: once I'd got to about the 11 o'clock position of the volume knob, the level was louder than I wanted, while below that setting the level changed dramatically with each little nudge. All this sometimes made finding the ideal volume difficult. However, I'm sure that will prove system-dependent—especially if you're not using a 1000Wpc amp such as the Titan!

At $10,999, the Musical Fidelity AMS Primo is a beautifully built, visually sophisticated, technically competent, evidently reliable, fully balanced, high-performance tube component that was a pleasure to live with, look at, and use. It also produces superb, musically graceful sound—I recommend it.

Musical Fidelity Ltd.
US distributor: Tempo Sales & Marketing
PO Box 541443
Waltham, MA 02454
(617) 314-9296