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Reviewer: Joël Chevassus
Financial Interests: click here
Source: Apple iMac, Squeezebox Touch modified + Welborne Labs PSU, Jadis JD2 Drive, Totaldac, Audio GD ref.5, Trends UD-10.1.
Preamp/amp: Wyred4Sound STP-SE, SPL Volume2, Orpheus Lab Three Monos, Trends TA-10.2, Hiraga Le Monstre
Speakers: Triangle Magellan Duetto, Athom GT1 [on loan]
Cables: Legato digital cable, Naturelle Audio digital cable, Naturelle Audio interconnects Live 8 MK2, Audio Art SC-5 SE speaker cables, Legato Precision speaker cables, Legato Fluidita interconnects
Power cords: Audio Art Power 1 SE
Stands & room: DIY stuff, Triangle TS400 stands, Vicoustic panels, Trinnov ST-2 HiFi [on loan]
Review component retail: ca. €4,900 in Europe (varies with country due to VAT)


Innovation in audio signal amplification has become unusual. In some ways we must admit that our manufacturers have reached a very satisfying level of performance and that outright bad amplifiers should nowadays be rather uncommon. Most companies working the home audio market have tried to catch the diversification train with integrated amplifiers that offer more than mere amplification by adding digital inputs or sometimes wireless connectivity. But if you focus solely on the amplification area, once again there generally are no big surprises. Perhaps some people still consider the field of ‘digital’ amps a revolution in progress but for the most part this technology is not new and has already been explored by electronics majors over many decades. The few genuine new developments in this area merely illustrate the ability of the hifi industry to still invest massively in R&D.


Let us now consider the field of small surprises. In France two startups recently tried to go beyond where amplifiers have gone before. The first was the prestigious and already very fashionable Devialet whose D-Premier was reviewed by Marja and Henk in these pages. Inside a very compact and elegant jewelry case Devialet delivers an unusual cocktail of cross-coupled class D and class A with supersonic measurements.


The second called more modestly for a specific rotary control dubbed StormFocus which is claimed to adjust the amplifier’s signal transmission mode to suit a given loudspeaker’s requirements. Adjusting current and voltage modes allows for a strategic modification of the amplifier output impedance. The concept of adaptable output impedance in a power amplifier is not really new technology and has been used to drive spring reverb units and various other transducers where current drive is preferable to voltage drive. Yet the notion to propose conveniently and fine variable settings to a hifi user is quite a first-time event.


The company describes it as the result of more than four years of R&D. Is the invention really helpful though? That’s the story this review shall develop. For now let’s just say it’s supposed to reduce typical phase distortion.