Specifications: Solid-state, remote-controlled, full-function line-level preamplifier with seven inputs, including one tape-loop, two balanced XLR, and four single-ended RCA.
Gain: Switchable, 6 or 12dB.
S/N ratio: 96dB unweighted.
THD: <0.01% at 1kHz, <0.01% at 20kHz.
Input impedance: 47k ohms.
Output impedance: 5 ohms. Maximum output: 14V.
Dimensions: 19" W by 14.5" D by 2.5" H, preamplifier; 11" W by 9" D by 2.5" H, power supply.
image: http://www.stereophile.com/images/archivesart/krellkrcprepic1.jpg
But there was a fly in the ointment. My system wasn't state-of-the-art by any stretch, but it was reasonably transparent. With the AR remote in the circuit, it was noticeably less so. As much as I hated to see it go, go it had to—and did. (I must also confess to having had a strong strain of Audio Calvinism at the time—deep down, it didn't feel right to have convenience in a high-end system.)But it did make me wonder: Since remote control offered such obvious benefits, why didn't the real high-end manufacturers explore ways to accomplish it without sonic tradeoffs? Why couldn't we have it all?
What a difference a decade makes. Today you'd be hard pressed to find a major high-end manufacturer who doesn't offer a full-function remote-controlled preamp. But let me tell you, it still comes as a shock when it's done as well as the Krell KRC-HR.
You can tell it's a Krell
'cause it's swell
Did I say full-function? The Krell is first—and foremost—an extremely sophisticated preamplifier. Its signal stages run in high-bias class-A and it features digital switching as much as possible divorced from the signal path. Volume control is achieved through an electronic, two-channel gain network that features over 300 discrete attenuation steps. No capacitors are used in the audio circuit paths, and the circuits themselves are laid out on high-quality four-layer glass/epoxy boards which, Krell claims, offer superior grounding as well as increased power stability.
The preamp has two balanced inputs (pin 2 hot, non-inverting), which utilize complementary circuits for increased linearity, as well as four single-ended inputs. One of these, S1, can accommodate Krell's Standard or Reference Phono Modules (which also mate with the KSL and KSL-2 line stages), while S4 can be switched for unity gain throughput. Single-ended and balanced outputs are provided; both are active at all times, meaning the KRC-HR can be used to control power amplifiers in two separate systems—assuming equivalent gain is desired in both at all times.
The preamp's heavy-duty power supply has its own chassis, whose umbilical is secured by nine-pin computer-cable-style connectors at both ends. Krell cautions strongly that the power supply be connected solidly to the preamp before being plugged in—always a good precaution when using an external PS.
The front panel is a tribute to uncluttered functionality. Its single knob—the gain control at the far right—even has an LED indicator set into it, allowing you to judge the level setting from across the room. All other switching is accomplished through oval-shaped soft-touch activators, each accompanied by a status-indicating LED. On the far left, above the mute switch, the six input selectors are arrayed in two rows in a pattern resembling an I Ching hexagram. Slightly to the right of these, in a vertical line, are the tape switch, the gain selector (6 and 12dB settings), and the polarity-inversion switch. In the middle of the front panel is a heavy band of black-anodized metal—matching the preamp's endcaps—which contains a wide I/R receptor window set above the trademark six-screw Krell nameplate. To the right of this is a twin row of five balance switches (incrementally indicating 1dB of adjustment for each channel) and the level-adjustment knob. All controls are replicated on the remote.
The fit'n'finish on the KRC-HR is first-rate. All metalwork, including XLR and RCA connectors, is superb. The unit is solid, built like a tank. Open it up and gaze at the circuit boards: they are gorgeous, but—even more to the point—they're jammed full of the highest-quality parts imaginable and affixed with remarkable precision. Krells don't come cheap, but you'll never wonder where the money went.
Leaving Krell enough alone
A lot of what I like about the KRC-HR is what it doesn't do. It doesn't hum, add noises, or call attention to itself in any way at all. Like most inhabitants of our modern age, I've become inured to the low levels of obtrusive noise that pervade our environment: fans, motors, transformers, fluorescent lighting ballasts—heck, even buzzing light-bulb filaments. Let's face it, we live in a miasma of unwanted sounds. But the Krell doesn't contribute to it at all; not only is it—and its power supply—dead quiet in operation, but its addition to the signal is virtually nil—far below my ability to perceive it.
This lack of noise makes its resolution about the highest I've ever experienced. I've heard stuff in favorite recordings that I've never heard in 20 years of listening. "Oh no!" I hear you bitching; "Not another lecture on music rustling, chair squeaking, and the newfound audibility of overdubbing!" No, that's all old news. All of that goes on—and must, as long as people actually make the music we listen to—but who cares? I'm talking about choices that the artists made about how to make the music—choices that can further inform my relationship to the music, now that I hear them.
Speaking of getting close, couldn't I get even closer if I eliminated all of the KRC-HR's circuitry and went direct from a high-quality variable output source like the KPS 20i/l? I had performed this experiment with some other, highly regarded preamps and found the sound straight out of the CD player more transparent and immediate.
To my surprise, this was not the case with the KRC-HR. With the preamp, music sounded just as fast and uncolored, but vastly more coherent and full-bodied. Listening to Emmylou Harris sing "Hard Times" (on At the Ryman, Reprise 26664, CD) through the KPS-20i/l direct, I was conscious of the small size of the theater and its rapid decay—factors that don't add a lot of body to an essentially acappella number such as this one. In comparison, the sound when the KRC was in the circuit was fuller, even better detailed, and more imbued with body. It could be argued, I suppose, that I'm reacting to a euphonic coloration, but I've never heard a euphonic coloration that made things sound more like themselves—which Emmylou and the Ryman did, through the KRC-HR.
Furthermore, the integration of the bass to the rest of the frequencies was more holistic. The song begins with an augmented chord harmonized by the Nash Ramblers as Emmylou sings the verse. With the KRC, the tonal spacing was tighter; the bass tonic sounded more of a piece with the intervals above it. Ditto the acoustic bass, which came through the '20i/l hot-rod (as it does with most systems) as an undifferentiated thump. With the KRC in the path, that thump was still pretty non-pitch-specific, but it had gained in detail: I could hear how Roy Huskey, Jr.'s string bass was coupled to the stage floor, its tone separate from the vocals above it. I could even hear the stage creak as the four singers leaned in closer to Emmylou for the chorus's tight harmonies. It goes against so much that I've learned over the years, but I'll be sheep-dipped if I weren't hearing more with the preamp in the circuit.
My heart Krells
I haven't heard many electronic devices as tonally transparent as the KRC-HR. When a component disappears totally, what's not to like?
As I write this, JA and I have just finished recording the 1996 Santa Fe Chamber Music Festival for an upcoming Stereophile CD. JA made some CDR dubs for me, primarily of a superb piano performance that will, sad to say, probably not get released. John hasn't done any mixdown yet—using the Sonic Solutions hard-disk editing system, he will align the four tracks in time then mix the two pairs together, as he did for our Sonata and Festival CDs—so the CDR contains two versions of the same night's performance: one through the crossed pair of B&K cardioids hanging in the center of the hall above the first row of the audience, the other taken from B&K omnis hanging a little farther back (less than a foot, really) on either side of the auditorium. Same musicians, same hall, same performance—the only differences are the microphones and their placement. It's a subtle test—after all, not much is different—yet sonically the takes are as different as day and night. The omnis have a fat, juicy, totally engaging sound—albeit with a hole in the middle you could drive a truck through—while the coincident pair have a hyper-detailed, up-close-and-very-personal sound that maps out the soundstage to the millimeter. BUT—and this is a big but—everything else about this performance should sound exactly the same, because the two takes did, after all, record the same event. Duh.
But the nature of distortion is to be inconsistent; I've heard a lot of systems though which the differences between the two takes would be exaggerated by nonlinearities in reproduction—exaggerated to the point where all you could hear would be those differences. The KRC-HR made the two takes sound identical other than the most obvious, indeed essential, differences. Dynamically, rhythmically, interpretively—they matched.
If you've never done a comparison of this nature, you might be tempted to sell it short. Most people never get to hear different perspectives on the same performance. They might listen to different interpretations of the same piece, some of them even incorporating the same artists or halls, but the same event? No. So we become used to hearing—used to listening for—the differences between events. We become experts on such differences. But listening to similar, very closely related versions of the same event requires a different sort of listening, and, I'm beginning to discover, a rare, fine analytic tool. The KRC-HR revealed itself to be a tool capable of such refined differentiation.
Creatures from the id?
However, as neutral and revealing as I think the Krell was, there was one thing it just didn't do: It didn't really present a well-differentiated stereo spread into a three-dimensional soundstage that included substantial depth information. This surprised me, for the KRC-HR had as much low-level resolution as I've ever heard. Even sounds way down in the mix were clearly audible and placed within an acoustic space. The preamp had no trouble illustrating the difference between a jazz club and a small theater, for instance. No, I was quite aware of the space within which the music had taken place.
But when it came to arranging the players in ranks, in orchestral recordings such as Corigliano's First Symphony (Erato 61132-2), or Bernstein/NYP's Mahler Third (DG 445 835-2), the KRC just put 'em up there in a relatively nonspecific clump. Well, maybe that's a bit hard on it—the musicians had quite detailed lateral spread, just not much depth. They weren't spread out in a single file, but they lacked that sense of existing in specific locations from front to back. This remained constant whether I played LPs or CDs, dynamic speakers or electrostats, tubed amps or solid-state.
How major a flaw is this? Well, I really value that sense of depth, but the KRC-HR ranks among the very finest audio products I've ever used—and, much to my surprise, I didn't really feel that I was all that deprived. Mostly, I just reveled in the music. There are audiophiles who claim that the whole soundstage depth thing is an overrated obsession—a point I have a lot more sympathy for now that I've lived with the Krell. This preamp could be the answer to their prayers. There is, however, something awfully seductive about having it all, and as much as I like the KRC-HR, I suspect I'd end up deeply yearning for an extra bit of real estate: the rear of the soundstage.
Whither thou Krellest
The Krell KRC-HR must certainly qualify as one of the truly great preamplifiers out there. It's well-built, well-thought-out, and a joy to use: it's convenient and reliable. In terms of tonal accuracy and low-level retrieval, it stands among the exalted few. I have some misgivings about its ability to portray the soundstage in the manner I desire, but this is a personal call—and a preference that not everyone shares. If you're looking for a preamp that can lay claim to being state-of-the-art, the KRC-HR demands a serious and extended audition.
ORIGINAL OWNER
Functional condition is flawless - works like new. Absolutely no functional issues - it's working flawlessly. Truly a remarkable piece of audio gear in outstanding condition - you will feel like you are opening a brand new unit.
This unit will be shipped with - fully insured.