The Copper Interview

Walter Schofield of Krell Industries, Part Two

In Part One (Issue 122) we interviewed Krell Industries’ Walter Schofield about his early audio career, some of the landmark products he worked on, his ideas about the return of audio shows and more. We continue the interview here with a focus on Walter’s current work with Krell.

Don Lindich: My first experience with Krell was in the late 1980s at a high-end audio store in South Florida, where a Krell KSA-100 amplifier was driving a pair of Apogee Caliper speakers. The source was a SOTA Star Sapphire turntable playing highlights from Bizet’s Carmen from a Deutsche Grammophon LP. To this day it remains one of the best, most pure-sounding audio demonstrations I have ever witnessed, and that I remember it in such detail over 30 years later speaks to that fact! That Krell KSA-100 drove the notoriously difficult Apogee ribbon speakers effortlessly.

That Krell KSA-100 was a Dan D’Agostino design, and for a long time the names Krell and D’Agostino, both Dan and Rondi D’Agostino, were practically synonymous with each other. (Both were ousted from the company in 2009 after a takeover, and Rondi eventually returned to Krell. Dan is now president of Dan D’Agostino Master Audio Systems.) Since then, the company has gone through many changes. Given the company was once so intimately associated with Dan and his design ethos, what is the current identity for Krell? How have things changed since his departure?

Walter Schofield.

Walter Schofield: David Goodman, our current director of product development, has been with Krell for 33 years and has been responsible for many of the company’s proprietary technologies.

Our design goals are: unmatched performance, and products that are elegant in appearance, with a compelling array of features including network connectivity.

For more than three decades, Dave has been instrumental in the continuous improvement in sound quality and capabilities of Krell’s entire product line. Additionally, he designed Krell’s critically acclaimed K-300i integrated amplifier. During its development he was able to substantially reduce the output impedance, while discovering a technique for greatly reducing harmonic distortion, resulting in a much more organic and natural sound.

Blast from the past: 750MCX mono power amplifier, circa 2000s.

Applying the techniques he learned in developing the K-300i, Dave’s engineering tenacity and innovation resulted in Krell’s current XD Technology. XD stands for “Xtended Dynamics, Dimensionality and Detail.” This resulted in the creation of Krell’s new XD Series of amplifiers, as well as the ability to retrofit current Krell products with XD technology.

After earning his BS in electrical engineering from Rensselaer Polytechnic Institute, David Goodman began his career with Sikorsky Aircraft as an avionics test engineer. He then joined Krell as a staff engineer, and soon becoming manager of engineering. Goodman has grown with the firm for over three decades.

Dave currently supervises a team of engineers in the concurrent development of multiple Krell products. His design experience includes responsibility for the electrical, mechanical and software design of every aspect and type of product that Krell manufactures.

He’s the co-inventor of Krell’s Sustained Plateau Bias technology, the forerunner of Krell’s proprietary iBias technology, which Dave has implemented throughout Krell’s current and forthcoming lines of amplifiers. iBias enables an amplifier to operate at the optimal level of Class A power without the excessive heat or power consumption normally associated with typical Class A designs.

K-300i integrated amplifier in silver and black. ($7,000 – $8,000 depending on configuration)

DL: How do today’s Krell amplifiers differ from such models of the past and how have they been improved?

WS: The implementation of iBias was a big step forward in Krell amplifier design. Krell’s history is rich with breakthrough Class A amplifiers that have helped build the company’s legacy of offering what we feel to be the best-sounding amplifiers available. Many audiophiles have considered Class A technology to be the best-sounding operating state for amplifiers, however, it has fallen out of fashion because of recent demands to reduce power consumption and heat in home electronics products.

Krell took this as a challenge. The result was iBias, a patent-pending circuit that delivers Class A operation without the excessive heat and wasted energy of conventional designs. What we hear is sound that is open and unconstrained, in a manner that rivals the true sound of voices and instruments.

Plainly stated, Krell feels that Class A designs are the most musically accurate circuit topology available. They do not suffer from the inherent distortions that all Class AB amplifiers experience. In a traditional Class A design, the output transistors conduct full current at all times regardless of the actual demand from the speakers. Often, only a fraction of this power is needed to reproduce an audio signal at normal listening levels. The rest of the power is dissipated through the amplifier’s heat sinks, producing large amounts of wasted heat. With Krell’s iBias technology, bias is dynamically adjusted, so the output transistors receive exactly as much power – but only as much power – as they need. The circuit works even at extremely low signal levels.

Solo 575 XD mono power amplifier ($12,500).

Previous efforts at using a “tracking” bias to accomplish what you could call “sliding bias Class A operation,” while effective, only measured the incoming signal and set bias levels from this information. iBias significantly elevates the effectiveness of previous designs by calculating bias from the output stage and output current. This seemingly small change in topology results in a dramatic improvement in sound quality, especially midrange richness and purity.

XD is another important technology. It was introduced in2018 with the K300i integrated amplifier and subsequently rolled out in all Krell amplifiers at the end of 2018 through 2019. The reviews and customer comments have been exceptionally positive.

During the development of the K-300i we discovered we could achieve substantial sonic improvements by lowering the output impedance below traditional norms. The improvement was so substantial we decided it deserved its own, unique “XD” designation. But it was no simple matter to implement. Lowering the output impedance affects the amplifier’s stability and transient response, so each stage prior to the output stage had to be re-tuned to work optimally with the lower output impedance. One of the advantages of lower output impedance is that the amplifier exerts more control over the loudspeaker drivers, and damps unwanted vibrational modes, allowing a more accurate reproduction of the original signal.

DL: Do you get a lot of repeat business from owners of vintage Krell products? And are there any differences between a Krell purchaser of yesterday and today?

WS: The customers of today and yesterday are similar in that they seek the best-available sound quality. That said, in addition to our traditional retail business, we’re getting more business from custom integrators.

DL: Krell has several product lines, though it is best-known for its amplifiers. Tell us about your other products.

WS: In addition to mono, stereo and multi-channel power amps and stereo integrated amplifiers we offer our Illusion and Illusion II preamplifiers, Foundation 4K Ultra HD Processor for A/V systems, our Vanguard Universal DAC Source, a 4K HDR switcher.

Illusion preamplifier ($16,500).

While some products may have been on the market for an extended period, we are consistently updating and upgrading them.

DL: What is your most popular product, and why do you think it has achieved that status?

WS: The new K300i is by far our most popular product, likely because it is the first one to incorporate our XD technology (the XD nomenclature is not added to the K300i, but it’s in there). It’s also our entry-level offering, yet we feel it sounds like a much more expensive product.

DL: Home theater is a notoriously difficult area for ultra-high-end manufacturers like Krell to compete in, due to rapidly-changing technology and features like Dolby Atmos and different forms of HDR being introduced seemingly every year. For the manufacturer, it is hard to spread the development costs required when the product doesn’t sell in mass-market quantities. An expensive home theater processor can become obsolete very quickly. For example, your own Krell Foundation 4K Processor, while highly regarded, does not have Dolby Atmos, a feature that is becoming a must-have in the premium segment. Do you have a strategy for competing in the home theater category and keeping up with rapidly-changing technology?

Foundation 4K surround processor ($8,250).

WS: We have three choices – one, to not manufacture preamp/processors at all and leave that to larger companies with more resources; two, to partner with a company that we can work with to enhance their offering(s); or three, to design such products in-house. We have two in-house Dolby Atmos/DTS-X pre/pros designed and at the ready. However, as you pointed out, they can become obsolete very quickly.

Krell is looking into option two, but we will only work with an OEM/ODM (original equipment manufacturer/original design manufacturer) partner if we can truly enhance their products to achieve the sound quality that we require of a Krell component. Stay tuned!

DL: Are most of your customers 2-channel or multichannel listeners?

WS: The split is about 60/40, leaning to 2-channel reproduction. However, the home theater segment has been growing consistently over the past few years.

DL: Where are Krell products manufactured?

WS: We source the majority of our components in North America, and assemble everything  in our Orange, Connecticut factory. We still source small bits from Asia; however, our focus is to bring all component manufacturing to North America with all future products, of which we have 23 introductions planned between Q1 of 2021 and the end of 2024.

DL: Have you encountered supply chain disruptions due to the pandemic?

WS: Unfortunately, yes. Our business has been trending up since the end of 2018, and we have not been able to keep up with that growth and have underestimated our needs for the components that go into Krell products. As a result, our suppliers have been scrambling to get our needs fulfilled as they ramp up for us. Combine that with parts availability issues to both them and us because of the pandemic, and it has created a perfect storm that we are not fond of.

We have always been a just-in-time manufacturer [a manufacturing method that requires quick delivery of parts and maintaining lean inventory levels – Ed.] and our lead times had been cut to two weeks in 2018 and 2019, but with our vastly increased sales and the shortages, we are running a bit behind. Our backlog has never been larger, a good issue to have in a way; however, we are asking our dealers and retail partners to be patient as we realign our resources. It’s getting better!

Illusion II preamplifier ($7,700).

DL: What does your dealer network look like these days?

WS: Many US dealer partners are committed to us, however, we have a way to go to rebuild Krell back into the iconic brand that reflects its technologically-leading nature. Our international partners feel the same: very committed to our growth; however, we will be making changes to that network as we have seen some recently-appointed partners exceed our expectations.

DL: What are the qualities you look for when establishing a Krell dealer?

WS: A sincere desire to bring the very best sound to their customers is a big one, as well as their commitment to customer service. Krell has not been the best at customer support; however, we are getting better and working diligently to enhance our customer support to the highest level in the industry. There is a long road ahead, but we like where we are and where we are heading.

DL: Do you plan on expanding your dealer network?

WS: Expansion would not be a correct term – we are seeking to reconnect with our legacy partners, and we’ve made great strides over the past two years. As we become a better partner, we expect the growth of our network to naturally occur.

During the pandemic, Krell has assembled a plan that addresses all aspects of our business, and the future looks very bright.

DL: Sadly, we do not have as many hi-fi stores as we used to, and the market is shifting to e-commerce or a blend of e-commerce and brick and mortar. For a company like Krell with premium products that are best seen, touched and heard to drive sales, how do you operate in such an environment?

WS: Our goal is to primarily partner with brick and mortar and custom integrators. That said, there are a couple of e-tailers that hold to manufacturers’ pricing policies and have a wide audience. In our opinion, their reach brings top brand names to so many end users, which we’ve seen to enhance sales for all partners, so we will not rule out potential partnerships in this area.

DL: If someone wants to purchase a Krell product but there is no dealer in their geographical area, can they still be accommodated?

Our dealer partner agreements are sacred to us, and if a customer contacts us, we will put them with our nearest partner in their geographic region. If the customer needs to hear a product and is nowhere near a dealer, we recommend they contact our sole online partner.

DL: What do you see as the future for Krell?

Krell has embarked on a mission with renewed vision, the enthusiastic support of a fully-engaged engineering department, and enterprise-wide support to develop as many new, technologically-advanced products as possible. Revenues were not only dramatically increased in 2019 and 2020; a plan was enacted to ready multiple product introductions to satisfy the pent-up demand for Krell products. We’ve also implemented infrastructure enhancements for customer service, manufacturing and operations.

We’re also planning marketing initiatives to reach a wider audience including enthusiasts around the globe, as well as high-net-worth individuals. Krell recognizes the necessity in reaching wide audiences of various age groups who are not aware that high-quality immersive music and theater experiences are available in their homes. Krell’s retail partners also recognize the iconic nature of the brand and are eager to play their integral role as well. I believe we are far from realizing our full potential.