Krell FBI integrated amplifier Page 2
As noted, I spent a few months last year listening to Krell's FPB-400cx, the beefier version of the 300cx that serves as the FBI's foundation. Certain things about the FBI sounded familiar: the tight deep bass, thunderous dynamics, and snappy transients. But, even at the outset, when I was using the single-ended inputs, there was something new: greater detail, even delicacy, in the timbres and textures of instruments.
Long gone are the days when Krell electronics were marred by what I felt was a cold glare in the upper midrange. In the last five or six years, Krell amps have warmed up in the middle octaves while preserving the pizzazz. But the FBI boosts Krell's traditional strengths while diminishing the weaknesses, both to new levels, in my experience.
For instance, even with the warmer midrange, silky violins weren't quite a Krell trademark. Yet when I put on Michael Tilson Thomas and the SFSO's recording of Mahler's Symphony 9 (SACD/CD, San Francisco Symphony 821936-0007-2), or Andrew Manze and Rachel Podger and the Academy of Ancient Music performing the solo and double violin concertos of J.S. Bach (SACD/CD, Harmonia Mundi HMU 807155), I heard not just silky, but shiveringly silky violins.
Some amps achieve tonal beauty at the cost of transient detail, but the FBI delivered both. With the Bach recording, it revealed the subtlest quivers of vibrato, the slightest ebb and flow of rhythm and dynamics. With Keith Jarrett's Carnegie Hall Concert (CD, ECM 1989/90)—a concert I attended—the FBI captured not only the creamy percussiveness of the Steinway grand, but also the slightest hesitations of Jarrett's rubato and the lightest shadings of his pedal work.
I've always put a high premium on how an audio component handles microdynamic contrasts—the slight variations in loudness or softness when a singer stresses a note, a violinist bows a bit harder or softer, or a drummer hits a cymbal in some different way that's barely perceptible. The FBI handled these as naturally as any amp I've heard. This isn't merely the sort of detail that audiophiles like to show off; it's the sort of detail that reveals the rhythm and the soul of music—and the presence of a human being blowing, bowing, singing, pounding, or otherwise playing it.
On Miles Davis' Cookin' (SACD, Analogue Productions LAPJ 7094 SA), when the band breaks into a faster tempo on "My Funny Valentine," listen to the way drummer Philly Joe Jones lets up on the hi-hat cymbal after he taps it with his stick. The effect adds an extra layer of rhythm and cool that I hadn't heard through other amplifiers the previous hundred or so times I'd played this album. Meanwhile, Miles' trumpet sounded golden, and Paul Chambers' bass was tightly strung and woody.
Bass, of course, is Krell's longstanding strong point, but I hadn't before heard such musical detail within the bass. The London Symphony's recording of Górecki's Third Symphony, conducted by David Zinman (CD, Elektra/Nonesuch 79282-2), begins with a very low, rumbly bass line—the double basses state the melody—which on many stereos you can barely hear. Listening to this passage through various systems over the years, I'd thought I'd discovered everything there was to hear in it, but the FBI unveiled more: dynamic variations in the bowing, two contrapuntal bass lines about three minutes into the first movement that I'd never before noticed, and simply more clarity and focus in the bass section—and all other sections of the orchestra—throughout.
The FBI also unraveled subtle harmonic variations with ease. On jazz trumpeter Dave Douglas' Charms of the Night Sky (CD, Winter & Winter 910 015-2), when he plays in unison with Mark Feldman's violin and Guy Klucevsek's accordion, I could hear their distinctive harmonic overtones much more clearly than I had before; in other words, I could better distinguish the three instruments, tonally, spatially, and harmonically. Yet they didn't appear as some overly analytical Etch-a-Sketch; the overtones blended in the ambience, as I've heard them do in concert.
Voices were also uncannily clear. If you've ever found it difficult to decipher lyrics sung by Bob Dylan, Donald Fagen, Randy Newman, or Rickie Lee Jones, take a listen to their recordings through the Krell FBI; it should be a clarifying experience. Dylan's Blood on the Tracks (SACD, Columbia CH 90323) sounded so clean—his voice so naked and articulate, the guitar strums so propulsive, the bass line so distinct—I would have guessed the recording had been dramatically remastered, had I not heard this disc so many times before.
Lest I give the impression that Krell has crafted an instrument of mere litheness and delicacy—a chamber ensemble among amplifiers—I should emphasize that the FBI could also let loose and roar. At the crescendo in the first movement of Mahler's Ninth, the FBI passed along the full force of the San Francisco Symphony without breaking up, backing down, or clutching in any way. Everything remained clear and distinct at high and low decibels.
I see that I haven't written anything about how the FBI handled soundstaging, so I'll say this: The soundstage was as wide, deep, precisely imaged, and densely layered as the recording and the rest of my system allowed.
Was there anything wrong with the FBI? Well, the highest frequencies sounded a bit truncated—or, if not cut off, a little less transparent than all the other octaves. This shortfall wasn't immediately obvious; to the extent it was noticeable, it wasn't at all annoying—and I'm one who is annoyed by chopped-off highs. I'm scrounging here for flaws.
I do have one caveat: As suggested near the beginning of this review, the FBI sounded much better with Krell's CAST circuit fully activated—that is, when the music source was plugged into the amp's CAST inputs. Using the balanced or single-ended inputs, the FBI still sounded very good; I wouldn't disavow anything I've written about it so far, though I might tone down some of the accolades a bit. In an A/B comparison adjusted for volume differences, the balanced and RCA inputs (with Nirvana interconnects) were hard to tell apart. But in A/B comparisons with the CAST input, both the balanced and RCA inputs fell short. They didn't reveal quite the rhythmic agility, dynamic detail, or bass clarity of the CAST circuit: I didn't hear all of Andrew Manze's and Rachel Podger's subtle fingerwork in the Bach violin concertos, or the full force of Dylan's strumming, or the obvious distinction between violins and violas in the Górecki and Mahler recordings.
Then again, CAST doesn't work outright miracles. I compared the CD and 180gm vinyl pressings of Miles Davis' Live Around the World (Warner Bros. 46032-2 and 46032-1) and Donald Fagen's Morph the Cat (Reprise 49975-2 and 49975-1). My turntable (which, of course, has only single-ended outputs) was plugged into the FBI's RCA inputs. Yet in the case of both recordings, the LP-into-RCA was superior to the CD-into-CAST. The two formats were closer than I've heard in similar analog-vs-digital face-offs, but the LP's ambience was a bit airier, Miles' trumpet and Fagen's voice a bit breathier, the background instruments a bit more 3D.
This comparison pointed to two conclusions. First, very good analog still has it over very good digital, in certain respects. Second, CAST or no CAST, the Krell FBI is an excellent amplifier; the difference between its inputs is one of degrees of excellence.
I can't presume to know what an economist would call your "utility function." That is, I can't know whether or not a certain product at a certain price—say, $16,500 for the Krell FBI integrated amplifier—is worth your money, given your tastes and income. But I can say that you won't hear everything the FBI has to offer unless you also buy a CD player that has CAST outputs, and the only such player that currently exists, as far as I know, is the Krell Evolution 505, which retails for $10,000.
In for 16 grand, in for 26? If that's where you're sitting (and if it is, mazel tov), go for it. Alas, it's not where I sit. So I petition Dan D'Agostino, on behalf of my fellow well-heeled but not that well-heeled music-lovers and audiophiles: Please, sir, can you make a digital player with CAST outputs (or maybe some kind of CAST converter) for a bit less? That will make the full package of the FBI's magic tricks accessible to many more of us.