Krell Demo A Killer

On April 14, Krell Industries invited the New York–based audio press to its first-ever American demonstration of its Evolution electronics separates, at Sound By Singer. In a surprise move, the company also debuted a complete "re-imagining" of its flagship loudspeaker, the LAT-1: the $55,000/pair LAT-1000. "We set out to improve the LAT-1," Krell CEO Dan D’Agostino said, "and in the end, probably the only parts we retained from the original design were the top and bottom panels. The LAT-1000 is essentially a completely new design—although it does retain the same footprint as the LAT-1, since that proved so popular in Japan that we didn't want to mess with it." And, he said, patting the aluminum top-plate, "Let me tell you, it was hard to pack all of this new technology into a package this size."

The Evolution series of electronics are all single-channel designs, allowing users to configure their systems into two-channel, 5.1 channel, 7.1 channel, or any other configuration they can imagine—or afford. The $25,000/each Evolution One is a fully balanced, Class-A, 450W monaural amplifier that employs Krell's proprietary Current Audio Signal Transmission (CAST) current-gain topologies from input to output; this keeps the audio signal in the current domain throughout the circuit, avoiding "unnecessary" current-to-voltage conversions, which, the company claims, "add distortion, require heavy feedback and severely limit bandwidth." Krell's press release says the Evolution One's circuitry "is virtually devoid of feedback and [the amplifier] sports a bandwidth an order of magnitude greater than any conventional design."

In addition to the current-gain circuitry, the Evolution One boasts a power section Krell deems "virtually limitless in its capability to drive any speaker to its full potential," by utilizing microprocessors that constantly monitor operating conditions and automatically adjust the operating parameters or shut the amplifier down to prevent damage to the input stages or loudspeakers. The output-stage is also adjusted to give true class-A operation no matter what the signal level. Krell has employed a similar scheme in its amplifiers dating back to the Krell Audio Standard, but D'Agostino said, "When we did this before, we used five or so levels of [bias] adjustment, and here we're using around 50, so it really is an order of magnitude greater."

The $20,000/each Evolution Two monophonic preamplifier is also a fully-balanced, class-A design which uses Krell's proprietary CAST inputs to "ensure absolute integrity of the audio signal." The Evolution Two's volume control features a 16-bit balanced resistor ladder, employing low-resistance, high-linearity solid-state switches, and discrete precision resistors "for the purest line stage possible."

Both the Evolutions One and Two are two-box single-channel designs, with separately housed massive power supplies that "make use of extensive electrical and magnetic shielding to keep radiated magnetic interference out of the circuits that are critical to music reproduction." Krell says it engineered new power supplies featuring dedicated 165VA toroidal transformers on the Evolution Two and two humongous 2100VA toroidal transformers for the Evolution One. Both supplies feature internal, high-current line-conditioning circuitry that Krell says filters out RF and compensates for asymmetric power waveforms "that could possibly affect the amplifiers' performance."

Fit'n'finish (and the gorgeous blue LEDs on the front panels) were commensurate with the units' prices—high as they might be.

The LAT-1000 features ScanSpeak and SEAS drivers, including an exclusive 8" aluminum-cone woofer (well, actually, three of them), which is available only on the '1000. The LAT-1000's tweeter is the top-of-the-line ScanSpeak 1" ring-radiator unit, and the midrange is provided by two 5.25" SEAS magnesium-cone drivers with high-excursion rubber surrounds and copper phase plugs. "Getting these new drivers built to our specifications was a lot harder than we anticipated," said D'Agostino. "We'd tell them what we wanted and they'd say, 'Oh, you don't mean that.' We'd insist that we did and they finally believed us."

The LAT-1000's crossover is all new, as well. The crossover network spans "almost the entire length of the inside cabinet and features a second-order low-pass Bessel filter on the woofers and midrange drivers and a third-order Butterworth filter on the tweeter." Even the port was re-worked on the LAT-1000. The new port, D'Agostino explained, is "more like an organ pipe in design. It's a 30" long aluminum square-section tube that lowers the bass frequency response by one-third of an octave."

For the demonstration, D'Agostino modified a Krell SACD Standard SACD player so that it, too, employed the CAST output stage, guaranteeing "that there is only one voltage-gain stage in the whole system."

And wow.

All the usual caveats apply. I'm not familiar with the soundroom at Sound By Singer. I don't know the Synergistic speaker cables that connected the Evolution Ones to the LAT-1000s (the interconnects were Krell's CAST cables, obviously). I've never heard the electronics or speaker before—it was the first time either had been publicly auditioned in North America, after all. So take my impressions with as many grains of salt as you need to make them suit your taste. But I have to say that I heard things in that demo that I have never heard another audio system do.

The most obvious being unbridled dynamic range. In song after song—ranging from solo drum kit to Dean Peer's plucked and thumbed bass to a Cecilia Bartoli aria—I heard music reproduced with the sort of effortless power that I've previously only heard live. When we audiophiles speak of reproductive purity, we frequently cite female vocals as though reproducing them is simply a matter of tonality. Well, that isn't the case, as Ms. Bartoli clearly proved. When the diva turned her head while reaching a crescendo, I could have sworn I heard her voice strike the microphone as though it was both a wave and and a particle. It was a quantum moment.

There were other revelations, such as the way the system reproduced the leading edge of transients and the tonal purity of a bass clarinet in a fairly avant-garde work I wasn't quite prepared to grapple with—at least not while I was still reeling from Ms. Bartoli's power and projection.

That single track will rank in my audio pantheon as one of those transforming instances when I was able to forget all about the gear and, for one glorious moment, simply wallow in the experience of music and its power to transcend space and time. There aren't many audio systems that can do that for a single instant. Can the Krell Evolution/LAT-1000 system do it consistently?

Only time and an extended audition will tell for sure, but my Magic 8-Ball says, "Signs point to yes."