An Interview with Jeff Poggi, CEO/President of Audio Research, and Warren Gehl, Design Engineer and Aural Evaluator
Audio Research’s musical story began in 1970 when the company was founded by William Zane (Bill) Johnson, former owner of Electronic Industries, a specialty audio store in Minneapolis. Throughout the 70s and 80s, Audio Research developed iconic tube-based preamplifier and amplifier designs that captivated the hearts and minds of music lovers and biggest audio critics of the time. My personal interest in Audio Research was born some 15 years ago when I had my first chance to listen to several of their components for an extended period of time. My experience was nothing shy of sublime. During this time, I discovered that Audio Research components were capable of painting incredibly massive, holographic soundstages and an intoxicating musicality that was simply irresistible. Not coincidentally, I seriously believe that it was Audio Research that got me truly hooked on high-end audio and the desire to chase the tail of the sonic dragon. Today, Audio Research continues to design and manufacture some of the most respected tube-based components in the world, at its state-of-the-art facility in Maple Grove, Minnesota.
Can you imagine my level of excitement when I was presented with a chance to interview two prominent members of the Audio Research team? I was as thrilled as Bart Simpson to meet his childhood hero Krusty the Clown! This fall, I had a chance to speak with Jeff Poggi, CEO/President of Audio Research, and Warren Gehl, Design Engineer and Aural Evaluator, and ask them a few questions. Here are the highlights of this conversation.
1. Suave Kajko (SK): For nearly 50 years, Audio Research has been building vacuum tube-based audio components. What is it about vacuum tubes that makes them so appealing to use as the foundation for new designs to this date?
Warren Gehl (WG): If conveying the musician’s innermost intentions – their subtlest of playing techniques and intimate shades of meaning – are of primary importance to the listener, the vacuum tube’s overall performance envelope alone is capable of sufficiently engaging nuance. The complexity and breadth of the tonal color palette (not a coloration) and spatial rendering in all dimensions are not as convincing through solid–state devices to many critical music lovers. The ’emotional bandwidth’ of music cannot be truncated and still completely satisfy. Tubes executed skillfully make music simultaneously relaxing and exciting, engaging and soothing. These qualities tend to be mutually exclusive in transistor-based audio systems. It is the very thing that makes listening to live music a spell-binding event – so addictive, renewing and memorable.
2. SK: What sonic advantages do vacuum tubes offer over transistors in the design of amps and preamps?
(WG): Beyond the above-described subjective attributes, carefully designed circuits utilizing cutting-edge modern-day vacuum tubes are lower in offensive odd-order harmonic distortion than transistors. The best tubes can now play music faster, more time coherently, with greater dynamics and even lower noise floor than transistors alone. Frequency bandwidth and bass control, as well as resolution and transparency to the source of current tube designs are now on par with solid-state performance, overall.
3. SK: Does your team listen to or experiment with transistor-based component designs in order to have a reference as to how some of the leading products in the market sound?
(WG): Between listening to live music regularly as an aural benchmark and hearing the latest solid-state electronics at both trade shows and in consumer’s systems, we gather a clear picture of where the performance chips fall vs. our ongoing tube design development. We find there’s nothing about transistor technology that is inherently superior to vacuum tubes under real, rapidly fluctuating dynamic music conditions. Recent inroads made at ARC with our latest vacuum tube designs, with regard to levels of conveying music’s essential truth and beauty, give us confidence that vacuum tube performance has a more promising and convincing future than ever.
4. SK: I understand that Audio Research recently relocated its office and manufacturing facility. Can you tell us what drove this decision and highlight some of the key advantages of the new space?
Jeff Poggi (JP): In August 2018 we moved into a new facility in Maple Grove, MN. Our ten-year lease in Plymouth was ending and it gave us the opportunity to invest into Audio Research by custom designing a new headquarters. We have a newly designed critical listening room that we use to listen to every product we build. Our new engineering space has been modernized and new CAD systems have been installed. Our production has become much more agile. We now build products to order. We can custom build each order in a matter of days. And, this has helped us launch many new models over the past year – the REF160M, REF160S, REFCD9SE, REFCD6SE, REF750SEL, and REF6SE.
5. SK: I recently had a chance to listen to the Audio Research LS28 preamp together with NOVO contributor Douglas Brown, who reviewed the unit. We found it to produce an extraordinarily vivid soundstage, with pin-point accuracy positioning of instruments and voices. It outperformed just about any modern preamp we can think of, regardless of price. Is there something particular in the design of Audio Research’s preamps that allows them to achieve this level of sound staging?
(WG): Each of our current vacuum-tube preamplifiers utilizes 6H30 tubes in a pure class-A, triode, zero-feedback amplification stage at its heart. A robust power supply capable of delivering all its energy very rapidly through components and wiring chosen for greatest time coherence is another key element. This all works to maximize spatial and timing organizational skills of the unfolding musical event.
6. SK: Some consumers are of the opinion that tube-based audio components are difficult to maintain and not worth the trouble. What do you say to these consumers? Has Audio Research done anything in its designs to make these components easier to maintain over the years?
(WG): I would recommend starting with a vacuum-tube preamplifier to see if the sound of tubes romances your ears and entices you further, and for easiest maintenance of its performance. We thoroughly test and measure all tube performance parameters for critically matched tube sets as needed in each product’s circuit. Our latest amps feature auto-biasing of the output tubes which makes it much easier for consumers to set up, compared to manual biasing. We also provide tube hour meters to monitor elapsed tube playing time on all current products.
7. SK: Do you source your vacuum tubes from one or more suppliers? Why do you prefer the tubes from this particular supplier or suppliers?
(WG): Our current products employ 6H30 small signal tubes and KT-150 power output tubes, each exclusively manufactured in Russia by a factory under American ownership and management. We find these to be the best overall performing tubes of their type for our design purposes. Older products use tubes we select from consistently reliable, sustainable sources.