Krell K-300i integrated amplifier

I was less than thrilled by Editor-in-Chief Jim Austin's suggestion to review the solid-state Krell K-300i integrated amplifier ($7000, plus an additional $1000 for the optional DAC). I had recently reviewed another $7000 integrated amplifier, the quite different hybrid Aesthetix Mimas, and while I ended up liking the Mimas a whole lot, I felt decidedly lukewarm about having to recalibrate expectations for another integrated, especially one that costs far less than my reference Dan D'Agostino Progression monoblocks ($38,000/pair) and whose DAC option is a fraction of the price of my reference dCS Rossini DAC/Rossini Clock combination ($31,498 plus cables). How good could it be?

There's something happening here (footnote 1)
There were also lingering questions about what had happened to Krell after its founders and co-owners, Dan D'Agostino and Rondi D'Agostino, were axed by an investor who, in the words of Krell's present-day COO Walter Schofield, "did not respect the legacy of the brand." Eventually, Schofield reports, the investor "walked away from the company."

Since Dan had already moved on and founded Dan D'Agostino Master Audio Systems, his former wife, Rondi, repurchased Krell in May 2016. After Schofield proposed a new business plan that would address reliability and performance issues, he came onboard as COO. The first all-new product from the re-envisioned and reinvigorated company, the Krell K-300i integrated amplifier, was released in early 2019 as the successor to Krell's US-manufactured Vanguard integrated amplifier.

That I had nothing to worry about (as if it were possible for a Jewish only child not to worry) became clear when I heard the K-300i shortly after its release, during Graham Audio's launch of their LS5/9f loudspeaker at Gig Harbor Audio near Seattle. After spending several hours listening to the speaker with an amplifier that did not do it for me at all, my ears perked up when proprietor Erik Owen switched to a brand-new, hardly-broken-in Krell K-300i. One listen to the difference in midrange (the Krell had a full and warm one, thank God) and top (the Krell's was smooth and extended rather than hard and unwelcoming) made clear that my editor was on to something. A mere two months later, a K-300i made its way to Port Townsend for review.

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What it is . . . became increasingly clear
While my sample of the K-300i was breaking in, Dave Goodman, Krell's longtime director of product development, gave me a rundown of its key attributes. Goodman, who was working for Sikorsky Aircraft when he discovered Krell's headquarters by chance while driving through an industrial park, has either designed or served as lead engineer for multiple Krell products over his 32 years with the company. Most recently, he designed the K-300i's optional DAC section and was responsible for the final development and implementation of its trademarked iBias technology (footnote 2).

The K-300i's key features include low-negative-feedback, fully differential circuitry, a 771VA power transformer with 80,000µF of capacitance, and a Cirrus Logic CS3318 volume control that runs balanced to ensure that balanced input signals, including those from the DAC, remain balanced until they reach the amplifier's main gain stage. All circuits up to the driver stage operate in pure class-A. Krell claims that this integrated was designed to output up to 150Wpc into 8 ohms and 300Wpc into 4 ohms, with its iBias technology allowing the amp to deliver up to the first 90W in class-A—"without the excessive heat and power consumption of traditional Class-A designs," Goodman told me by phone. (For his complete discussion of iBias and other unique aspects of the K-300i's design, please see the sidebar.)

The front panel includes power, source selection, navigation, menu, and volume buttons; a USB-A receptacle for playback from USB sticks; and an illuminated display. All of the panel's indicators except for volume level were easy to read from my music room's sweet spot, which is located approximately 12' away from my Wilson Audio Alexia 2 loudspeakers. You can assign custom names to sources, adjust volume offset to compensate for different source output levels, choose between variable and fixed output levels, and use the Fixed option to enable a home theater surround-sound processor to control the volume of the left and right front speakers along with all of the other home theater speakers.

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The Krell K-300i's rear panel includes two pairs of balanced analog audio inputs and three pairs of single-ended analog audio inputs. Given that my reference D'Agostino Progression monoblocks only accept balanced inputs, I stuck with balanced interconnects throughout the review period. Because the K-300i's sole pair of preamp outputs is single- ended, and I didn't want to use single-ended–to-balanced adapters (which might have compromised sound quality),

I was unable to pair it with the Progressions to test it as a stand-alone preamp.

The Krell's loudspeaker outputs come with EU-approved plastic safety fittings, a challenge for bifocal wearers. But once you get the hang of things, it's easy to connect and tighten spade lugs.

A number of the K-300i's rear-panel inputs and outputs are activated with the optional digital module, which uses the ES9028PRO Sabre DAC chip. These include a USB-B input, which accepts signal from external devices such as HDs, NAS drives, and computers; a Bluetooth receiver with aptX; HDMI 2.0a and HDCP2.2 inputs and a single HDMI output; and TosLink optical and S/PDIF coax inputs. An Ethernet input comes standard, as do an RS232 control, baseband RC5 input, and 12VDC trigger input and output.

The DAC, which fully decodes and renders MQA and is a Roon endpoint, decodes PCM up to 24/192 through the rear-panel coax, HDMI, and USB-B inputs; the optical input is limited to 24/96. Higher PCM rates are downsampled. The USB-B input also plays DSD up to 128; DSD256 may be converted to a lower DSD rate, depending on the capabilities of the source device. Both network audio and the front-panel USB-A input work in conjunction with a downloadable ConversDigital mConnect Control app for iOS and Android to decode PCM up to 24/192; those inputs only play DSD64 and will not down-convert higher DSD rates. Depending on the capabilities of your network music server software, you can get around DSD limitations by setting it to down-convert higher DSD rates to DSD64 or to PCM. (Roon can do this.) The mConnect Control app also handles network streaming audio from Spotify, Tidal, Deezer, Qobuz, and vTuner internet radio. It won't wash your windows, however.

There's also a very handy remote control that can select inputs, control and mute volume, adjust balance, and access menu functions. Replacing its two AAA batteries is a pain, however, because it involves using a supplied Torx screwdriver to remove and replace four teeny, easily lost T10 screws.

The K-300i's manual cautions against plugging it into a power conditioner. When questioned, Goodman said, "Krell amps have always had very large power supplies that deliver a lot of current. This means that the power conditioner has to be at least as big as the power supply in the amplifier to avoid limiting power and negatively impacting the sound. The K-300i may be one of our smaller amplifiers, but it has an over-750W power supply. To get everything you can out of it, your power conditioner should be rated for at least 1000W." Goodman subsequently acknowledged that conditioners such as AudioQuest's Niagara 5000, which, when run from a 120V supply, can sustain 20 amps for up to 25ms, should be adequate when the K-300i is connected to one of its high-current outlets. Thus, I stuck with my own Niagara 5000, which I use with my reference D'Agostino amplifiers.

Stop: Hey, what's that sound?
My review strategy was pretty straightforward, at least at the start. To evaluate the K-300i solely as an integrated amplifier, I bypassed its DAC section by sending signal from the Rossini DAC's balanced analog outputs to one of the Krell's pairs of balanced analog inputs. After turning the Rossini DAC's volume all the way up, I used the K-300i's front- panel navigation menu to select the correct input. (I could have used the remote control instead, but I kept it on the couch to control volume.) The source was my customary Roon ROCK-equipped NUC, with playback controlled by a Roon app downloaded to my iPad Pro.


Footnote 1: With thanks to Buffalo Springfield, whose 1967 song "For What It's Worth" figured in one of my many awakenings.

Footnote 2: Former Krell engineer Todd Eichenbaum did the original proof-of-concept work on iBias.

COMPANY INFO
Krell Industries, LLC
45 Connair Road
Orange, CT 96477-3650
USA
(203) 799-9954
ARTICLE CONTENTS

COMMENTS
Ortofan's picture

not enough heatsink.

Suppose that the designer of the Krell amp was still working at Sikorsky.
Would their helicopters overheat and shut off in mid-flight after running at one-third power for 55 minutes?

For $7K one could have instead the Marantz PM-KI Ruby integrated amp and SA-KI Ruby SACD player/DAC combo.
https://audio.com.pl/testy/stereo/odtwarzacz-cd-wzmacniacz/3021-marantz-sa-pm-ki-ruby
https://www.musicdirect.com/integrated-amp/Marantz-KI-RUBY-Reference-Bundle

JRT's picture
ortofan wrote:

Suppose that the designer of the Krell amp was still working at Sikorsky.
Would their helicopters overheat and shut off in mid-flight after running at one-third power for 55 minutes?

The lubricant in a helicopter transmission is not only to address the tribology of friction, wear, and lubrication, but also serves to cool the working surfaces of the gear teeth and transport that heat to an oil cooler. With that in mind, read the brief article at the following link.

https://www.google.com/amp/s/www.ainonline.com/aviation-news/aviation-international-news/2013-01-01/main-gearbox-remains-helicopters-achilles-heel%3famp

And more recently, "accelerated wear" has plagued the main rotor gearbox in the new CH-53K, the US Marine Corps new heavy lift helicopter, and has been one of the sources of delays in replacing old fatigued and worn CH-53E.

https://www.marinecorpstimes.com/news/your-marine-corps/2019/02/04/the-marine-corps-new-ch-53k-is-a-mess-this-is-why-its-operational-date-could-face-delays/

Bogolu Haranath's picture

Even with all that grease applied, helicopter motors don't sound musical anyway :-) .......

Ortofan's picture

... in a product, such as a helicopter, where simply pulling over to the side of the road, so to speak, is not an option. Every attempt is made during the development process to design out such potential failures, and/or include redundant back-up systems, and then test prototypes to beyond the expected operating conditions and life.

The measurements performed by Stereophile, including the one-hour at one-third rated power preconditioning test for amplifiers, are not a secret. Thus, one might imagine that any company submitting an amp for review would confirm that it can pass that test - unless they would rather debate its usefulness.

Bogolu Haranath's picture

They forgot to add 'Prestone' before sending the review sample :-) .......

TJ's picture

... for your very fine and interesting review. Great to see Krell "back" again, kudos to Dave Goodman! Hope you get a chance to review one of their Duo XD amps.

dial's picture

Krell is a good brand and always will be. They keep quality going, see them at audio salons (only separates in fact).
A part of the hifi legend, at least in North America. It's good they still are in, in Europe a lot have ceased operation (UK, France and Germany come to mind). I hope they'll last forever.
Only minor complaints. The design could have been better without this bump in the middle. Looks like an old Naim, isn't it ?
I also miss a knob volume control, well you are not by 3D LABS, right ?
But the rear panel shows poor cinch and speakers sockets, a shame for price asked.
Measurements are good to very good, nothing surprising.
Thanks for your article.

Bogolu Haranath's picture

Primare I35 Prisma integrated amp ($5,000, reviewed by Hi-Fi news) and Hegel H390 integrated amp ($6,000, reviewed by S&V magazine) are also in this price range :-) .......

Kursun's picture

First 90W in class A ?
With that heatsink?
Absolutely no way!

rwwear's picture

The iBias allows 90 watts class A.

tonykaz's picture

What perspective can describe this box of parts as "high value" ?

Certainly not the High Values of the Schiit designer types.

But then again...

If this device does a ton of Class A from that smallish chassis it's an engineering marvel.

Dubious claims aside...

Should we be comfortable with a Company using someone else's Name, isn't buying Krell also buying Dan ?

Spending serious money for Krell and not getting Dan D'Augistino seems a little empty. ( like buying Chinese ROLEX Watches )

Tony in Venice

dc_bruce's picture

I don't think that's very fair. Dan has been --ahem-- divorced from Krell for quite some time. Moreover, Dan was not the only guy responsible for Krell designs when he was there. I suspect that the lesser products, like the KAV-300i (which I owned back in the day) were not the recipients of a whole lot of the chief designer's time. The item under review is at least the third version of this product to bear the name KAV-300i.
It's good to see Krell trying to serve this end of the market; so many high-end companies have retreated "upstairs."

I believe Krell had its issues with its "SACD Standard" and subsequent generation of "ultimate" disc players. Through no fault of the company's, their optical drive supplier shipped them 2 generations of failure-prone drives. I'm sure customers were unhappy and warranty claims must hav been significant.

tonykaz's picture

You're probably right, I'm not being fair ( sort-of ) with my comparison.

Still,

I think of those superb Krell Amps that I could never seem to get my ( Esoteric Audio ) hands.

Of course...

I keep thinking of Dan & Krell in 1985 terms ( like an old geezer I am ) pining for those "good old days".

Krell had powerful magic. Dan still has powerful magic.

So, If we're gonna spend Big Bucks for a Brand Name there should be the Name accompanying the deal, shouldn't there ?

Anyway, I was hoping to read about something wonderful, something breakthrough, something having Krell-like spectacular performance and appearance, something that makes the reviewer feel like the singing artist is kissing him with pillowy embraces.

It's probably all Dan's fault, dammit, he set-us-up to expect new highs in everything.

Tony in Venice

ps. I was never one of Dan D'Augistio's Dealers, probably because I couldn't come up with the $$$$$ to stock the entire line with "one to show and two to go" Plus have the Apogee Loudspeaker Line. Phew !! I would've loved to have Dan prancing around my Store meeting Customers.

dc_bruce's picture

and dealers who sell this super-expensive stuff, like d'Agostino. Cash flow management is torture. I was a director of a small scientific instrument company that sold devices used to quality control silicon chips. Typically, these sold for about $1.5M each and the company would sell 2 to 4 of them a year. While that was not the company's only revenue source (it sold much smaller cryogenic devices and service/support contracts on the big stuff), missing an anticipated sale really screwed up the books for that year.

It's easy to rail at the stratospheric prices of this stuff, but when you figure in all of the costs other than materials and labor -- financing inventory (at either the dealer or manufacturer level), maintaining adequate working capital to deal with wide swings in cash flow -- they're not always so exorbitant. Whether they are a good value (as compared to less expensive products) is, of course, another matter about which I don't think one can generalize.

audiodoctornj's picture

Been following these comments so I have to chime in with a few points:

The mythos of Dan Dagastino is just silly, Dan was never a trained electrical engineer, Dan came up with a design that was over built and had the ability to drive a very low load to power the Apogee full range and that was the beginning of Krell and the KSA 50.

Dan's leadership of Krell was more strategic in running the company and overseeing the final designs of the product line which had grown quite a lot into amps, preamps, integrated amps, CD players, dacs, transports, and phono stages, and eventually speakers and even a subwoofer.

Most of Krell's modern designs for the last 20 years were designed by Dave Goodman who came up with the Ibias design and the new XD topology.

As an original Krell KSA 250 owner, as well as a FPB 450 MCX mono blocks and selling Krell for years, the new gear is by and far the best sounding Krell gear they have ever made.

The older Krell amps did have a more pronounced bass slam, than the newer XD amplifiers, the newer XD amplifiers have a far greater sense of involvement, midrange liquidity, and sense of space, than the original designs.

The K300i is a fantastic integrated amplifier which can easily stand aside any competitive integrated amplifier for the price range including the Hegel and the Primare.

Neither of these amplifies has the unique feature set of the K300i which includes Blue Tooth, HDMI inputs, and a great built in streamer along with a massive amount of Class A power, the Primare is a Class D design and the Hegel although excellent does not have the tube like liquidity that the XD circuitry provides.

All told the new Krell K300i is a fantastic performer, as per the gentleman who is decrying value lets look at that statement

Start with a good $5,000.00 integrated amplifier

add a good Dac $2,000.00

add a streamer $ 500.00

add a digital cable $ 200.00

add a set of interc $ 500.00

you would have $8,200.00 vs the $8,000.00 all in one K300i with dac

so the K300i is really quite reasonably priced for all it does and the superb sound quality it delivers.

Audio Doctor NJ

Bogolu Haranath's picture

It would be interesting to see a comparison review with the more expensive D'Agostino Progression integrated amp ($25,000) ......... May be JVS could do the comparison review :-) .........

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