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The Krell, in comparison, appears to have an acoustically "drier" presentation of ambient space, better separating the instruments and voices from the surrounding acoustic. In some cases, with recordings erring on the side of extreme digititis, the Krell can sound bleached and a bit thin. But there's no doubt that the KBL is more of a sonic chameleon, changing more with each recording than the competing No.26. Soundstage dimensionality, forward vs distant overall perspective, and harmonic textures can change dramatically between different recordings, allowing the best to sound remarkably…
Andrew Litton, Music Director of the Bournemouth Symphony and a member of our musicians' listening group, immediately noticed this during an extended A/B comparison of the two preamps a few months ago. While he enjoyed the larger soundstage and harmonically warmer presentation of the No.26, he felt that the musical honesty of the KBL unquestionably reproduced his own recordings of Tchaikovsky Symphonies 1 and 2 (Bournemouth Symphony Orchestra, Virgin VC 7 91119-2) more accurately. He described the Levinson No.26 as "heavy and dark sounding," "covered," and "slightly compressed," while the…
An even more spectacular display of the KBL's abilities to unravel complex musical lines can be heard in a world-premiere recording of Antoine Brumel's Mass for Twelve Voices, with Paul van Nevel and the Huelgas Ensemble on Sony Classical "Vivarte" SK 46348 (reviewed in this issue). This remarkable performance was recorded in the very reverberant Chapel of the Irish College in Leuven, Belgium, and is, without a doubt, the finest job I've ever heard of vocal music recorded in a church (footnote 6). The presentation was very spacious and expansive with the No.26, creating an illusion of a…
Sidebar 1: Specification
Description: Solid-state, class-A, DC-coupled, line-level, stereo preamplifier. S/N ratio: 100dB (A-weighted). Input impedance: 10k ohms. Output impedance: 0.5 ohms. Frequency range: 0.1Hz-250kHz. Voltage swing: 65V peak-peak (23V RMS). Voltage gain: 3x (approximately 9dB).
Dimensions: 2.25" H by 19" W by 12" D (preamplifier); 2.5" H by 9" W by 12" D (power supply). Weight: 27 lbs.
Price: $4500 (1991); no longer available (2003). Approximate number of dealers: 50.
Manufacturer: Krell Industries, 35 Higgins Drive, Milford, CT 06460 (1991); Krell…
Sidebar 2: System Context
My reference system currently consists of a Theta Pro Generation II D/A processor with balanced outputs, Mark Levinson No.26 line-level preamplifier, Krell KSA-250 and Mark Levinson No.23 power amplifiers, and B&W Matrix 800 speakers. A Levinson No.23.5 power amp arrived after the KBL, and was subsequently substituted for the No.23 (the 23.5 is much better than the 23), as well as a pair of Krell MDA-300 monoblocks (a truly phenomenal amplifier!). Several CD drives were used (Krell MD-1 and Esoteric P-10, P-500, and P-2), as well as two Krell D/A converters…
Sidebar 3: Measurements (from April 1992, Vol.15 No.4)
The line-stage-only KBL used in its balanced input/balanced output mode had an output impedance of under 4 ohms at any setting of the level control. Its balanced input impedance for either channel varied between 66.5k ohms and 73.9k ohms, with the higher values at the lower settings of the level control. In the unbalanced mode (input and output) the output impedance measured under 2.2 ohms at any setting of the level control (including interconnects), and the input impedance measured between 45.2k ohms and 49k ohms at various level…
Canadian loudspeaker company PSB International celebrated both its 25th anniversary in July and the 10th anniversary of the introduction of its Stratus series. (I review the latest version of the flagship Stratus speaker, the Gold i, elsewhere in this issue.) Started by Paul Barton and two friends in the summer of 1972, PSB Speakers was named after Paul and his high-school sweetheart Sue (now his wife). Paul & Sue Barton Speakers is now part of Lenbrook Industries, which distributes NAD, Marantz, and Bang & Olufsen in Canada, and which in turn is part of the Canadian conglomerate…
Atkinson: What was PSB's first commercial loudspeaker?
Barton: I'm embarrassed to say! It was a 12" two-way. [laughter] The company no longer exists, but Canadians who read Stereophile will probably remember a company called Radio Speakers of Canada. The speaker used one of their 12" woofers with a 1" Philips dome tweeter.
Atkinson: When did you start a relationship with Canada's National Research Council?
Barton: The National Research Council of Canada—NRC, as it's called—is a government-funded group of institutions that employ about 1000 Ph.D.s in all of the sciences,…
Barton: Because the first-arrival sound is predominant. Sound power compiles a lot of measurements to give you a picture of what the speaker's total energy output is. Picture the speaker in the middle of a sphere and microphone measurements being made all over the surface of that sphere. In a room, in varying degrees depending on how well the room is damped, some of the energy from all of the directions around the loudspeaker will eventually reach the listener at some point in time. The intensity of that will be very much determined by the surface of the room itself and the directivity of…
Barton: Exactly. It must have been a strange configuration, as you don't often get off-axis peaks at high frequencies as much as you get a bad blend between the directivity of the larger driver crossing over to a much smaller driver.
Atkinson: The speaker that has been my favorite for a while, the B&W Silver Signature, is a two-way with an 8" woofer. So what you have is a little bit of off-axis flare at the bottom of the tweeter passband. But the woofer appears to be rolled off a little early to give a shallow depression in the on-axis response in exactly the same region where the…