TESTED: Krell S-300i Integrated Amplifier

Equipment report
Integrated amplifiers
Krell S-300i
TESTED: Krell S-300i Integrated Amplifier

Few components strike fear in an audiophile’s lumbar region like the heavyweight electronics from Krell. Its current lineup includes the Evolution series of electronics and LAT speakers. And no one will forget the Master Reference subwoofer, an overwhelming 400-pound homage to on-demand seismic energy. But there’s another side to Krell, as exemplified in the S-300i. This integrated amplifier is little more than four inches high, but this powerhouse is pure Krell through and through.

It may be modest in profile but sciatica sufferers should cautiously bend those knees when trying to hoist it. At 43 pounds, it outputs 150Wpc and doubles that rating into 4 ohms thus likely making the S-300i the most powerful amp in this price range. Whereas many integrated amp have trouble driving loudspeakers that drop below a nominal 8-ohm impedance, the S-300i merely yawns at such challenges.

In sonic personality the S-300i could very well be the Lance Armstrong of integrated amplification. Like the physique of the Tour de France champ, the S-300i’s sonics are conveyed with muscular definition and not a single ounce of flab. Its sound is built for speed and for the critical analysis of a recording—not a rough translation. The result is a drier tonality that’s not exactly sweet but rather sweetly exacting. If your biases tend toward the lush, florid, romantic, or, goodness knows, euphonic, the S-300i may not entirely win your heart. However, if it’s precision-cut images and transient acceleration you’re seeking, you’ve found your ride.

To that end the Krell really shines on a solo acoustic guitar recording like Laurence Juber’s LJ Plays The Beatles [Solid Air Records]. From the instant Juber began playing his transcription of “Yesterday,” I could hear the sound of his fingertips and nails striking the strings. From this slightly softened transient it was apparent that Juber wasn’t using fingerpicks which typically create an annoying clatter. The S-300i reproduced the full body and bloom of this close-miked recording in a way that was comparable to some of the best amps I’ve had on hand recently. Don’t look for it to flatter an edgy recording with a peaky hard vocal or the aggressive winds and strings in an orchestra. However, a highly naturalistic one like cellist Pieter Wispelwey’s version of Bloch’s Kol Nidre [Channel Classics] produced rewarding string tone and a full-bodied representation of acoustic space. I could hear a velvety midrange smoothness slipstreaming alongside the speed and immediacy of this marvelous recording. And the imaging on this track was wonderfully precise—as good as I’ve ever heard it and that’s saying something. The S-300i seemed to relish diving into the middle of the orchestra plucking out low-level details and timbres with ease.

In bass response, the S-300i doesn’t have the bone-chilling footprint of Krell’s colossal flagships—it won’t dredge the bottom of the low-frequency lake and it lacks the bass bloom and decay that define the most elite amps in this segment. But dynamically it’s no shrinking violet either. Its strength is its excellent low-frequency control; for example, during Paul Simon’s “You Can Call Me Al” it produced those popping electric bass lines with the kind of pitch and texture that might even redefine the integrated amplifier in this price range.

It loses just a little steam and finesse at the margins. Thus harmonic information in the upper treble seems a little more earthbound, more finite. There’s a slight rigidity during the Paul Simon/Linda Ronstadt duet of “Under African Skies” [Graceland, Columbia] that I didn’t hear with mondo-integrated amps like the Pass INT-150 and ATC SIA2-150—both priced north of $6500, I should add. It also won’t plow through percussive dynamics with quite the energy of these well-regarded amps or duplicate the scale or weight they impart to a symphony orchestra. Finally, there’s a modest reduction of depth and soundstage width—an example would be the background voices on Simon’s Graceland album, which should be located at the furthest extremes of the speakers’ side panels.

Krell is a company I don’t ordinarily associate with blue-plate audio values. I had to continually remind myself that the S-300i is only a $2500 amp; yet I was comparing it to amps twice the price and more. What blew me away was the balance Krell has struck between the sonic expectations of traditional audiophiles and a new generation of hobbyists whose priorities also include modern functionality and features. Choosing an integrated amp just got a whole lot more complicated. But remember to bend your knees.



The S-300i is a smooth operator from a company that knows the territory. Its functions and configurability illustrate Krell’s crossover expertise in home cinema and the high end. Fit and finish are stunning-. Wholly designed in Orange, CT, and built in China to Krell’s specifications, the casework is seamless; edges and trim are smoothly rounded. Borrowing some of its styling cues and ergonomics from the S-1000 controller, the richly polished aluminum front panel houses buttons with hermetically sealed push-button switches that engage with a reassuring click. The machined aluminum volume/navigation wheel generates just the right amount of feedback to the hand. It also accesses the S-300i’s control menus, which can be viewed on the unit’s front-panel display. The menu system controls such functions as balance, input trim, input naming, and muting level. Krell also gets the adjustably illuminated display just right-—readable by human beings, not eagles. The rear panel includes three RCA line-level inputs, a balanced XLR input, and an iPod/iPhone interface (a cable is supplied) that taps audio from the fully differential output. Unfortunately the interface does not export the iPod’s metadata to the front-panel display—an oversight in my view. Naturally there’s a theater pass-through mode. External control systems such as AMX and Crestron touchscreens haven’t been forgotten either—the S-300i provides 3.5mm jacks for IR input and 12-volt trigger input and output, as well as an RS232 connector. High-quality speaker cable terminals complete this well-equipped package. A full-function remote is provided.

No shortage of clout in the power department, either. The S-300i combines a fully balanced discrete Class A preamplifier circuit controlled by an R-2R resistor-ladder volume control and a discrete output stage rated rated at 150 watts per channel into 8 ohms and 300 watts per channel into 4 ohms. Its circuit borrows the Current Mode technology used in Krell’s top-of-the-line Evolution amps and preamps. Krell touts its massive 750VA toroidal transformer and 38,000 microfarads of capacitance as among the more potent ever incorporated into an integrated amplifier.  –Neil Gader



Krell S-300i integrated amplifier

Power Output:150Wpc into 8 ohms, 300Wpc into 4 ohms
Inputs:Three RCA, one XLR (all line inputs)
Dimensions:17.25” x 4.20” x 17.50”
Weight:43 lbs.

Krell Industries, Inc.

45 Connair Road
Orange, CT 06477
(203) 799-9954

Associated Equipment

Sota Cosmos Series III turntable; SME V pick-up arm; Ortofon 2M Black, Benz Glider Wood cartridge; JR Transrotor Phono II; Esoteric X-05, Sony DVP-9000ES; ATC SCM20-2, Sonics Amerigo, Paradigm Monitor 9, Tara Labs Omega, Synergistic Tesla Apex, Nordost Baldur, Kimber Kable BiFocal XL; Synergistic Tesla, Wireworld Silver Electra & Kimber Palladian power cords; Synergistic Tesla Power Cell 

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