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Reviewer: Joël Chevassus
Financial Interests: click here
Source: Esoteric K-03, Lumin, Apple Imac Lion Osx /Audirvana, Trends UD-10.1, MacBook Lion OSX with HiFace USB bridge
Preamp/amp: Coincident Technologies Statement Line preamplifier, SPL Volume2, Luxman C-800f, Luxman M-800a x 2 (bridged), Orpheus Lab Three M, Trends TA-10.2
Speakers: Vivid Audio K1, Lawrence Audio Violin [on loan]
Cables: Skywire Audio 2020 digital cable, Naturelle Audio interconnects Live 8 MK2, Grimm Audio TPM interconnects, High Fidelity CT1 Enhanced speakers and interconnects
Power Cords: Audio Art Power 1 SE, Supra, DIY
Stands & room: Music Tools Alicia furniture & Music Tools bass traps (on loan), DAAD 4 bass traps, Microsorber room insulation, PYT Panels
Review component retail in Europe: €35.000/pr

Context: After the Ayon Audio Orthos XS, this was the second pair of big boy amps in my listening room: Chord's SPM-6000 monaural amplifiers. They are not the most powerful pair from the British manufacturer and this simple fact might update you on my current physical status. I'm not strong and bright-eyed enough to carry upstairs 200 floor-crunching kilos of Chord’s flagship, the SPM-12000. But it seems that the SPM-6000 was designed with the same no-compromise philosophy and with the same high-tech design. Standing 20cm tall but a colossal 66cm deep, these amps will not fit inside most pieces of hifi furniture. I cannot imagine these two anywhere but in a dedicated listening room. Despite the case work being impeccably finished, the SPM-6000 look so radically different that they demand their own place. Just as a Lamborghini Diablo cannot be driven by just anyone so John Franks’ babies are not destined for rookies with empty pockets.

Only the 40kg/ea. weight misses other various superlative features of this contender to be reasonably manageable in this crazy range of true muscle amp tests.

Priced at a herniatic €35.000 the pair the SPM-6000 are rated for massive amounts of power thanks to their unique high-frequency power supplies. Those explain their relatively low weight. When people think of switching power supplies they mostly think class D. This conjures up very light compact gear as Devialet have expressed over the past few years as a kind of quintessence or modern archetype on the genre. It thus seems amazing to stare at two machos of 40kg each which flaunt high power efficiency where very little heat gets dissipated unlike other muscular pieces of steel which could be used as space heaters during the winter months.

Coming from the aerospace industry, Chords’ founder John Franks has always been involved in getting the maximum amount of power from the lightest designs. Recognized as one of the most influential specialists of switch-mode power supplies, Franks still dreams of absolute performance from switching output devices.

He recently declared that “the fundamental switching frequency of a class D amplifier using silicon technology is around 200kHz. You can’t go much higher than that with silicon... No one at present has a digital amp … a D class amplifier that sounds any good.” He also disclosed that “Chord are working on delivering what promises to be a game-changing class D amplifier”.

But right now whilst we await the most advanced technical class D refinements using mysterious gallium nitride devices, this review is on an association of custom-built Mosfet output stage with three 5th-generation switching power supplies in parallel. The high-frequency SMPS operate in the 80kHz range unlike conventional power supplies which plow the 50-60Hz range. Chord's operate simultaneously on the positive and negative rails for a still more dynamic response.

Chord Electronics have used a lot of advanced design to perfect this second iteration of their mono amplifiers SPM-6000 MKII such as Silicon Graphics work stations, schematic capture, ASIC design, SPICE simulation, mechanical design and morphing. My question was far more mundane. After so much time spent with the 'ancient' bipolar Luxman and tubed Ayon amplifiers, what might the sonic benefits of such expensive accumulation of high technologies be coming to us directly from the aerospace industry?