APL10

Reviewer: Srajan Ebaen
Financial interests: click here
Main system: Sources: Retina 5K 27" iMac (4GHz quad-core with Turbo, 32GB RAM, 3TB FusionDrive, OSX Yosemite. iTunes 14.4), PureMusic 3.02, Audirvana 3, Qobuz, Tidal, Denafrips Terminator+ clock-synced to Gaia; Avatar CDP; Soundaware D100Pro SD transport; Preamp: Vinnie Rossi L2 Signature; Power amps: Kinki Studio EX-B7 monos; Headamp: Kinki Studio; Phones: HifiMan Susvara; Loudspeakers: Audio Physic Codex; Cube Audio Nenuphar; Aurai Audio M1 [on loan]; Cables: Complete loom of Allnic Audio ZL; Power delivery: Vibex Granada/Alhambra on all source components, Vibex One 11R on amps; Equipment rack: Artesanía Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc Krion and glass amp stands; Sundry accessories: Acoustic System resonators, LessLoss Firewall for loudspeakers, Furutech NCF Signal Boosters; Room: 4 x 6m with high gabled beam ceiling opening into 4 x 8m kitchen and 5 x 8m living room so no wall behind the listening chairs
2nd system: Source: Soundaware D300Ref SD transport; DAC/pre: Denafrips Terminator; Preamplifier: icOn 4Pro Model 3 SE; Amplifier: Crayon CFA-1.2; Loudspeakers: sound|kaos Vox 3awf, Zu Submission subwoofer; Power delivery: Furutech GTO 2D NCF; Equipment rack: Hifistay Mythology Transform X-Frame [on extended loan];  Sundry accessories: Audioquest Fog Lifters; Furutech NFC Clear Lines; Room: ~4x6m
Desktop system: Source: HP Z230 work station Win7/64; USB bridge: Audiobyte Hydra X+; Headamp: COS Engineering H1; Phones: Final D8000; Powered speakers: Fram Audio Midi 150
Upstairs headfi system: Source: Soundaware A280 SD transport; Integrated amplifiers: Schiit Jotunheim R or Bakoon AMP-13R; Phones: Raal-Requisite SR1a; Loudspeakers: Acelec Model One
2-channel video system: Source: Oppo BDP-105; DAC: Kinki Studio; Preamp: Wyred4Sound STP-SE II; Power amp: LinnenberG Liszt; Loudspeakers: German Physiks HRS-120; Room: ~6x4m
Review component retail: €12'600 ex VAT, add €1'400 for optional 1.5m PRC-01 power cord

A preamp is the heart and center piece of any fine hifi system. | Any streamer or DAC with digital volume makes a preamp obsolete. Which is it?

John Atkinson of Stereophile once expressed words to the first sentiment's effect. They remain widely shared by experienced listeners. Words to the second effect embed in a recent reader email.

"Hi Srajan & Joël, after reading your reviews in 6moons/Audiophile-Magazine and some emails with Joël, I'm taking the plunge to purchase a Kinki EX-M7. I will tether it to a Lumin T2, take advantage of the Leedh processing championed by Joël and stream music via Roon Nucleus to my Vivid B1 Decade speakers. I've been using a Devialet Expert 220 Pro for an all-in-one system for some time and am eager to try something different; much different. My thanks to you two for your clear-eyed reviews!"

Coming from a French one-box system, Michael Fanning's new system will combine a streaming DAC and stereo amp. Lumin's license of Leedh's processing—also adopted by Métronome, Soulution and Vermeer—embeds proprietary DSP code to process volume with zero loss regardless of attenuation. As proud owner of a 101D direct-heated triode preamp plus alternate minimalist spl volume controller, Joël's early exposure to Gilles Milot's unique software code made him aware of just how much distortion even premium analog volume controls inject still. For him that really rendered classic preamps obsoleedh. For the time being, that too would hold for Michael whose shared ownership of Vivid speakers made Joël a trusted advisor.

I presently sit somewhere in the middle. In our main system, I use a premium Pál Nagy autoformer passive. That usurped the throne previously defended by a direct-coupled DHT preamp from Vinnie Rossi which I'd run with premium Elrog ER50. That machine now runs upstairs. In short, the linestage subject of the standalone classic preamp without phono spans the gamut from active to activated passive to passive circuits; from volume control as on-chip/discrete switched resistor ladders, light-dependent resistors aka LDR, potentiometers, multi-tapped transformers/autoformers; from gain devices as on-chip/discrete opamps, single-ended or dual-differential transistors and/or small/big tubes plus any number of gain stages.

Today's preamp isn't for people who believe in 0.0000% measured distortion. Designer Luca Chiomenti joins Eduardo de Lima, Jean Hiraga, Michael van den Broeck, Nelson Pass, Vladimir Shushurin and others in proposing that human BSP—biological signal processing—is neither linear nor without its own distortion. The sound we hear isn't the one traveling through the air. It's what first filtered through our BSP before our brain registered it. Purest is the sound whose inherent distortion is canceled out on evolutionary auto pilot by our little grey cells. There's no conscious effort involved. There's no listener fatigue from our brain working extra to tune out wrongs. Casual lingo refers to numerous possible audio wrongs as digititis, etch, glare, sizzle, cyborg bass—one of my pet peeves—special effects, hyper realism or simply, hifi-sounding. Now hifi means artificial, mechanical, unnatural and not real. A German immigrant to the UK might say große oder kleine Scheiße but shit nonetheless.

According to this perspective—the fine art of hifi criminology—if the harmonic distortion of our gear defines correctly in profile and dynamic behavior, it behaves like feed-forward error correction. Our ear/brain overlooks it because it expects this distortion from all the naturally occurring sounds which refined it across millennia. What our ear/brain doesn't expect is alien distortion which only entered its orbit in the last 100 years. That's a mere blink of an eye in the evolutionary scheme of human DNA. This alien distortion is generated by electronics which pursue the zero distortion ideal by whatever means necessary. Wholesale absence of distortion is unnatural. So is the wrong kind of distortion no matter how small. This belief thus differs from season-to-taste libertarianism whereby whatever pleases us most goes. "Some more 2nd harmonic THD, Sam, but go easier on the 5th and 8th."

Luca exploits carefully tuned complementary THD which our brain is programmed to discard. His goal is to present our bio signal processor with no evidence that our playback differs fundamentally from a crying baby, purring cat, cooing bird, crashing surf, rain, fire, wind, lightning, talking and even snoring – just in case you were zzz'ing off. Sure, we could immediately question how anyone could possibly know how human hearing works this precisely unless they were knee deep into neurosciences. We could point at the huge variable of loudspeaker mates whose own distortion profile will assuredly interfere with that of our carefully tuned electronics. For our purposes, it simply suffices to know that today's preamp is based on this design philosophy. All audio designers must work with some personal blueprint to guide their process. This tends to be a combination of measurements and listening. What to listen for and measure can be a closely guarded secret. Vladimir Shushurin of Lamm in fact gained notoriety for claiming that he needn't listen at all. He developed a sufficiently comprehensive map of distortion figures and behavior whereby measured overlay with it equals sonic success. If nothing else, the takeaway could be that just owning a flashy spectrum analyzer to set oneself up as a critic of hifi circuits is nowhere near sufficient to play today's game. The suite of measurements Luca pursues aren't to be found in the usual textbooks. As such we won't expect detailed descriptions either on how his circuit goes about securing them.