SOUND TRAVELS
The amplifiers in Hugh Dean’s system were designed and built by the man himself. Dean also built the pair of VSonics Transmission Line Speakers he uses in his home system.
Peter Xeni and Paul Boon interview High Dean, of Aspen Audio, to hear his philosophies about music, sound, the hi-fi industry and discover what gear he uses in his own home.
Hugh Dean has been manufacturing amplifiers in Melbourne for more than 20 years. He owns a company called Aspen Amplifiers. His Maya and Saksa solid-state power units were marketed as ‘bespoke’ units in Australia and overseas. His current products can be seen at www.aksaonline.com. The VSonics loudspeakers in his system were designed by Laurie Menogue. Aspen Amplifiers sells them in ‘kit’ form for DIY builders and Hugh built a pair for himself.
An erudite audio scholar, Hugh Dean rejected a career in IT to pursue a life in audio manufacturing to satisfy what he says is his ‘lifelong obsession’ with audio.
Dean’s location in the leafy suburb of Rosanna in Melbourne’s north-east remains a cornerstone of the local hi-fi scene and he says that his small business still satisfies him, 24 years after selling his first commercial amplifier. That amplifier, the Glass Harmony, was inspired by his concert-going and musical background. ‘I still go to classical and other concerts and it gives me a reference and perspective into producing good sound at home,’ he says.
Hugh’s precocious interest in classical music began at the age of six and evolved into learning piano and later, playing the pipe organ. ‘After 50 years of studying sound and listening to music, I think I’ve developed a good ear for what constitutes good sound,’ says the now 67-year-old jokingly.
As a child, Hugh loved Mozart’s Jupiter symphony. He continues to enjoy classical music, but also enjoys modern jazz, as well as music by Bob Dylan, Leonard Cohen, Fleetwood Mac and many more, not to mention Daft Punk and other electronica.
ST: Do you have a first musical memory, a first unforgettable experience that left an impression?
HD: Yes, most definitely. It was Mozart’s Eine Kleine Nachtmusik. I was a child then, when my mother owned a Williamson 15-watt tube amplifier. I also love Rachmaninov, Borodin, Rimsky-Korsakov and Dvorak. But Elgar’s Enigma Variations is the one I want played when I fall off the twig!
ST: In what way does music affect your life, your emotions and the way you feel?
HD: Great music makes me weep. Music is so powerful. Mozart did that for me. Not long ago, I saw a modern ballet set to Tchaikovsky’s Rococco Variations and I literally wept through it. ST: How do you see the way we will consume music in the future?
HD: Music is moving to the internet, and away from the tangible, for financial reasons. Vinyl won’t grow any more. I don’t like vinyl anyway; it is so fragile. The mechanical extraction of the music signal from vinyl is very simple. It introduces considerable second, third and fourth harmonics to the signal, giving it warmth; the third gives it the ‘perceived’ sharpness of resolution and the fourth gives it ‘body’, and in this sense the vinyl phonograph is an ‘effects box’. If you put the fifth harmonic in it—which many amplifiers add—it gives it a machine sound, like a reciprocating machine. For me, vinyl is certainly a lovely sound, but I have attempted to design amplifiers over many years to try to simulate and improve on this sound using digital sources. The advantages of a digital source are low cost, small size, convenience, mobility and easy storage and mechanical robustness. I love the digital storage system. These days I have a tiny HDD with 3,500 CDs on it. I can listen continuously for years and not hear the same album twice!
ST: Was there ever a golden age in audio? And if there was, where do you think have we got better and where have we dropped the ball?
HD: I think it was between 1955 and 1975 and it was originally driven in Britain by Peter Walker at Quad, Harold Leak, and Peter Baxandall. In America it was first driven Bart Locanthi, Henry Kloss, David Hafler, and then in later years by Nelson Pass and Charles Hansen (Ayre). The millennials are driving the industry now and they have different standards—not lower or higher—just different. They like slam, top-end, bass and detail and need a battery supply because the music is now mobile. It seems that issues of musicality and depth of image are not as important as they once used to be.
ST: What is your prime philosophy in evaluating audio?
HD: Someone once said that perception is more important than reality. This has been true for the audio industry, and also true for much of the equipment we design for audio reproduction. The human ear seeks a ‘natural’ sound, a primal and evolutionary reality, born of the need to recognise external threats. Audiophiles focus on ‘unnatural sounds’ from their systems using their life experience of music and instrumentation, to seek a ‘natural’ sound… or at least what they perceive as reality. This begs the question of why so many people love vinyl and tube amps, which create considerable distortion.
The focus therefore becomes subjective, in which case selecting a sound system becomes just a personal choice, like selecting clothing, food or a car.
ST: We’re told that you established Aspen Audio to, and we quote: ‘Provide an alternative choice to the production line sameness of commercial manufacturers chasing a dollar and driven by the Japanese THD wars of the eighties.’
HD: Years ago, I decided to build a solid-state amp for commercial sale because I then believed—and still do—that the vast majority of amps on the market are poorly conceived. The engineering is good, but the conception and the psychoacoustics are incomplete. However, distortion is inevitable, so we are obliged to work with it somehow. The key is the high THD figures of tube amplifiers; they are orders of magnitude higher than solid-state amplifiers, yet they sound very good. Perhaps modern amps simply don’t have the right philosophy, leading to an unmusical presentation? Nevertheless the THD marketing continues, driven by the awareness that this approach does still attract sales—people love numbers! My solid-state amps have a tube sound with a harmonic profile that tends to bring up the second harmonic, but with much more resolution, stronger drive and less noise. They are sweet and warm; 70 per cent of audiophiles like that, and the other 30 per cent are usually purists who like something with a zero THD and buy on specs.
Many prefer ‘the ice-pick in your ear’ clinical, dry sound which is normal fare with high global negative feedback design amps. But most like a warm sound, which is evidenced by tube and phono amp sales.
ST: You claim that most tube amplifiers don’t have the slam and impact needed for rock music, and that your aim is to provide that, while retaining that hallmark tube warmth and musicality.
HD: The transistors I use in my Maya range are used in hybrid motor cars to drive electric traction motors. I use 70-amp MOSFETs with a 250-volt rating which are thermally and electrically more robust than large bipolar transistors, and they cost me $10 each, which is outstanding value for money. Money is very important: You have to build something that is five times cheaper than your retail price to accommodate R&D, transportation, business expenses, advertising and market level sales. Most of the sound of an amplifier is from the first, second and third stages, not the fourth output stage. If the output stage is well biased at 150 milliamps on each device—so inactive devices are still on until the cycle is up to 5 or 6 volts or more, it ensures that your first watt is going to be Class-A. In short, by using strong design and economical solid-state components, I have cut costs and added some of the qualities of a tube amplifier, but retained resolution, slam and musicality.
ST: How do you judge the quality of an amplifier?
HD: My judgement is both by ear, called ‘voicing’, and by measurement. Measurements ensure that you are building what you are designing for and that every unit you build is the same; so you need frequency limits—both top and bottom—and THD limits that are accurate to within 0.06% at full power. Bandwidth depends on function and requirement. An audio amplifier with a high-frequency that’s too extended will pick up radio frequency interference from mobile phones and from TV and radio broadcasts. Bandwidth needs to be restricted so that it is 1dB down maximum at 35kHz and 4 to 6dB down at about 100kHz. Without a filter my amps would essentially go out to about one megahertz; I design them intrinsically very fast for stability reasons. I build amps to audiophile requirements, and my amps will drive any speaker because of their unusual feedback regime. Global negative feedback on my amps is never higher than 30dB which, using light compensation, makes them intrinsically stable with any load.
Over the years, Hugh Dean has met the demands he has placed on himself, and met the demands of others who enjoy his bon vivant style…and his fine hi-fi system.
Story by Peter Xeni. Interview by Peter Xeni and Paul Boon.