Description: Solid-state stereo power amplifier. Maximum power output: 50W into 8 ohms (17dBW), doubles with each halving of load impedance down to 1 ohm.
Dimensions: 19" W by 9" H (including feet) by 19" D (including handles). Weight: 60 lbs (net).
Serial number of unit tested: not noted.
Price: $1900 (1995); no longer available (2007).
Manufacturer: Krell Industries, Milford, CT 06460 (1985); Krell Industries, 45 Connair Drive, Orange, CT 06477. Tel: (203) 799-9954. Fax: (203) 799-9796. Web: www.krellonline.com.
search
Sidebar: Specifications
There's always a certain amount of jockeying for position at the very top of the High End. Every few months, a new star burns brightly, getting all the attention. While the constant turnover at the cutting edge helps to define the state of the art, audiophiles should keep their eyes on the longer term. It's a company's track record—examined over a period of years—which defines its position in the market and the credibility of its products.
Ever since I made the acquaintance of my first Krell product—the KSA-50 power amplifier—I've been impressed by this Connecticut-based company'…
Early amplifier stages have fully regulated supplies, later ones distributed wide-bandwidth supply decoupling.
Once upon a time, Krell power amplifiers claimed and achieved low distortion factors. This wasn't a specific design feature, but a byproduct of their inherently linear circuitry. As good-sounding modern amplifiers continue to demonstrate, the link between sound quality and low distortion figures measured in the lab with continuous tones is a tenuous one. A low-feedback design will generally produce higher distortion; Krell has no qualms in revealing figures for full-power total…
The maximum output available from an amplifier, and, more pertinently, the maximum clean acoustic output it can achieve with the owner's chosen speakers in a specific room, are controlled by the true speaker loading, the true speaker sensitivity, and the capability of the power amplifier when driving this load.
In theory, an amplifier doesn't need to have a high power reserve, since most loudspeakers are specified as having a 4–8 ohm impedance, typically averaging 6 ohms. In practice, however, loudspeaker impedances can frequently be unexpectedly severe. A nominally 8 ohm loudspeaker…
Sidebar 1: Specifications
Description: solid-state stereo power amplifier with "Sustained Plateau" output-stage biasing. Power output: 200Wpc into 8 ohms, 400Wpc into 4 ohms, 800Wpc into 2 ohms, 1600Wpc into 1 ohm, one channel driven (all power outputs equivalent to 23dBW). Damping factor: 80. THD: 0.1% at 1kHz, 0.2–0.5% at 20kHz, at full power.
Dimensions: 19" W by 8.5" H by 21" D.
Price: $7500 (1994); no longer available (2007). Approximate number of dealers: 55. Warranty: 5 years parts and labor, limited transferable.
Manufacturer: Krell Industries, 45 Connair Drive, Orange,…
Sidebar 2: System
A wide selection of ancillary components was available for this review. Comparison preamplifiers ranged from the Audio Research LS-5 to Krell's own KRC-2, by way of a Conrad-Johnson PF1. Power amplifiers included the Audio Research VT150, the Krell KSA-100S, Meridian 605, Naim NAP250, and Conrad-Johnson Premier Eleven. Loudspeakers used were the Apogee Mini Grand system, Wilson WATT 3s/Puppy 2s, Quad ESL-63s, and Epos ES-11s.
Digital sources included the PS Lambda and Reference Link combination, the Krell MD10 and Reference 64 combination, an Accuphase DP70V,…
Sidebar 3: Measurements
An idling power consumption of 125W was noted, close to spec and confirming this amplifier's moderate standby consumption, especially in view of the high power and current capabilities. That massive transformer was mechanically silent even on the UK's 50Hz AC supply.
There was no denying this amplifier's big heart. The KSA-200S is rated as a 23dBW design, which is equivalent to an output power of 200Wpc, with one channel driven. The output is claimed to double with each successive halving of load impedance, right down to 1 ohm. Such was the reserve present…
J.S. BACH: The Goldberg Variations, BWV 988
Glenn Gould, piano (1955); Yamaha Disklavier Pro piano, "Re-Performance" by Zenph Studios Sony Classical 8697-03350-2 (SACD/CD). 2007. Howard H. Scott, prod. (1955 mono sessions); Steven Epstein, prod. (2007 stereo, multichannel, and binaural sessions); Peter Cook, Richard King, eng. (2007); Dennis Patterson, asst. eng. (2007); Marc Wienert, piano voicer (worked with Gould); Ron Giesbrecht, calibration. Zenph project team: Mikhail Krishtal, Anatoly Larkin, Peter J. Schwaller, John Q. Walker. DDD. TT: 77:02.
Performance *****
Sonics…
Glenn Gould, piano (1955); Yamaha Disklavier Pro piano, "Re-Performance" by Zenph Studios Sony Classical 8697-03350-2 (SACD/CD). 2007. Howard H. Scott, prod. (1955 mono sessions); Steven Epstein, prod. (2007 stereo, multichannel, and binaural sessions); Peter Cook, Richard King, eng. (2007); Dennis Patterson, asst. eng. (2007); Marc Wienert, piano voicer (worked with Gould); Ron Giesbrecht, calibration. Zenph project team: Mikhail Krishtal, Anatoly Larkin, Peter J. Schwaller, John Q. Walker. DDD. TT: 77:02.
Performance *****
Sonics…
"Why didn't they choose a color set?" I had been reminiscing about the early days of TV and how my parents bought a black-and-white set so we could watch the Coronation of Queen Elizabeth II in 1953. My daughter Emily's question had me stumped. It is difficult to explain to someone born 10 years after the launch of CD—someone who, for example, has never seen, let alone used, a typewriter, and who enjoys a comparatively infinite set of choices among mature 21st-century technologies—that it was not always thus.
All of us are inexorably shaped by our personal histories. Baby-boomers like me…
"Onkyo Returns to its Stereo Roots to Debut New Digital Amplifier Technology." This heading of the press release for Onkyo's A-9555 digital integrated amplifier was surely intended to warm the cockles of the two-channel audiophile's heart. Some of us remember the Onkyo Grand Integra amplifiers of the 1980s, which were considered competitive with the big Krells and Mark Levinsons of the day. To refresh my memory, I looked through my Stereophile archives and found the December 1985 issue (Vol.8 No.8), which included Larry Greenhill's review of the Grand Integra M-510, a 300Wpc power amplifier…