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Sennheiser HD-800. Of the majors this 300Ω design would arguably seem most widely recognized. It appears a lot more discussed than beyerdynamic's 600Ω T1 for example. Compared to either, AKG's new K812 is virtually unknown still. As one notes with flagship headphones designed to include portable use, impedance drops. beyer's T5p is 32Ω, AKG's new flagship is 36Ω, audio technica's W5000 is 40Ω, Fostex's TH900 hits a new low of 25Ω. The average headphone port designed for such low-impedance loads delivers a mere fraction of its power into an HD-800. That could thus find itself sorely under-driven. That we'd not expect from our €7'950  deck. But as we already know from challenging speakers, amps that can go loud enough needn't make top sound just because. This was brought home by the transformation the CMA-1 wrought on the HD-800. I usually find the Germans a bit bright, etchy, forward and—vis-à-vis my beloved bass monster, the Audeze LCD-2 v2—also lightweight down low. With the stock leash I frankly didn't enjoy them much at all. Hence my early Ken Ball harness from ALO Audio whose new braiding machine produces far snazzier cables since.

Into this purely personal scenario Roland Krammer's 'vitamin H' injection of humanity created very unexpected gentleness and downright civility. As though to undermine all potential suspicions of subtractive trickery, the Senn's always strong point of spacious airiness grew noticeably stronger yet. This completely rewrote my opinion of it. The combination was all about deep space and fluffy aeration; a sparkling but sweet white wine to the LCD2's very robust earthy red. Clearly the Sennheiser's particular load was a harsher mistress than I'd realized when this much potential had remained untapped. Streaming Mercan Dede's Dünya for richly layered laterally very expansive soundscapes with powerful infra bass showed how even the low freqs had benefited. Whilst not to Audeze standards, they no longer were a weak part of the overall equation. This was an absolutely brilliant pairing!

Mad and Alpha dogs. The reminder that one needn't spend the HD800's $1'199 to get a good hit of the high end came from Dan Clark's $300 Fostex build called Mad Dog. Whilst insane on this fiscal scale, the CHA-1's wholesale exorcism of this can's typical darkness and cobwebs in the rafters demonstrated the benefits of circuit speed from exploded bandwidth. It also showed how stepping up to Dan's $600 3D-printed ear cups gets one uncomfortably close to my LCD-2 or can even overtake 'em if the former have the Crayon advantage but not the latter.


Audeze LCD-2, LCD-3, LCD-XC. Low-Ω all, the new 'Fazor-tech' fitted XC on this amp showed speed advantages I'd not realized as such over its older siblings despite their being open-backed and it closed. The amp also showed a somewhat bigger innate advantage of the 3 over the 2 than I'd heard before. This returns us to my earlier statement: "The Crayon has tweaked timing precision and noise floor to such a degree that otherwise insignificant or marginal differences magnify to really matter." Just in this context it's fair to say that for the CHA-1 the Mad Dog for example nearly isn't good enough. Its inherent limitations become a road block for the amp to fully stretch its legs.


AKG K702. This 62Ω can is justly notorious for playing a bit hard to get. For its low asking price (a quarter of the hi-zoot majors) it's capable of surprising performance but tends to be more demanding of amplification than most to make it so. The CHA-1's likely idealized drive confirmed both true potential and how even in a best-case scenario the design remains texturally dry. It lacks the Senn's sinuousness and sparkle and what I call fat man's elegance in the fluidity plus mass of the Audeze recipe. If you agree with my assessment, you could prefer Trafomatic-type valve power to elevate the K702's lack of textural richness.

HifiMan HE-500 & HE-6. As direct competitors to Audeze, plugging in the HE-500 planar instantly injected more reverb action over the AKG to show what the K702 won't do. Whilst the new HE-560 finally updates Fang Bian's fit'n'finish issues to keep up with the current Jones on comfort/build and gets easier to drive, I didn't have one. But the CHA-1 didn't care. As king of lazy and with the amp fed a balanced 4V signal, even the HE-6 couldn't advance the triangular volume pointer past high noon before it fully awoke. As noted for our earlier sibling rivalries, the CHA-1 again maximized the differences between my two HifiMans. This highlighted the increase of top-end energy of the costlier one. As clearly an Audeze man when it comes to planars—Fostex's TH900 remains a future date—I'm simply not the proper person to sing the full praises of the HifiMan aesthetic.

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Beyerdynamic T1 & T5p. With prior amp owners or loaners I'd quite preferred both of these over my HD-800; and the sealed T5p over the open T1. Whilst the Crayon didn't upset my pecking order for the two beyers, it did between the two brands. If my earlier arm-chair assessment of the HD-800 vs. T1 popularity was correct, I could finally associate with it and sign on its dotted line. The HD-800 saw the biggest performance makeover of my lot. With the sealed Fazor-tech Audeze it jumped straight to the front of my CHA-1 line for reasons related to the K702. Both beyers were drier than the Sennheiser. Whilst both LCD-3 and HD-800 imaged as out of head as I've heard, the latter's added treble effulgence made for the 'spaciest' performer I had on hand. In sequence my three top picks for the Crayon would thus be the HD800 followed by the LCD-XC and LCD-3. I suspect the LCD-X would dethrone its sealed sibling to either occupy the #2 slot or usurp the throne.

Finish lines. Smart phones are multi-taskers. They be portable telephones, photo and video cameras, WiFi web surfers, app executors and video/music players. They've popularized headfi as the fastest growing category in consumer audio. High-end audio's response are statement headphones and amplifiers to match. With every passing year the definition of what 'statement' could or should mean moves up. Cynics detect cold opportunism. Idealists see growing experience with associated results. Mid-level headfi amps still tend to multi-task. They might double as preamp or DAC or do both. The CHA-1 doesn't. It does just one thing: drive headphones from a single-ended or balanced feed. This epitomizes high-end audio's MO. It's about application-specific optimization taken to the limit without concern over cost. Here cost reflects not just the item itself. It includes an ailing high-margin retail model which struggles with relevance, added value, unstable currency exchanges and a shopper mentality of 'one global price, ship today and discount for the privilege' created by the Internet's rapid response. And it includes small-volume artisanal production. This boutique approach drives up parts and sub-assembly costs. Here those are high-frequency multi-layer circuit boards outsourced to hi-tech non-audio suppliers. Reality bites.

It's this very reality which birthed and now attempts to support the CHA-1. What this deck adds over certain high-priced pretenders is real engineering, specifically high-speed circuit design for MHz/GHz signal processing. That such an out-of-industry approach applied to our 20Hz-20kHz bandwidth has merit is borne out by superlative performance. But just as you wouldn't associate a street-legal race car with normal tyres, standard shocks and civilian gasoline whilst expecting to tap anywhere near its actual potential, the CHA-1 too demands top-quality ancillaries. It's like a hand-held shot blown up large. No matter how fancy your lens or on-chip anti-shake DSP, there will be blur and loss of fine detail. So treat the CHA-1 with due respect. Then you'll have one massive near hyper-realist full-color photograph to frame and hang over your fireplace. It won't be a silly trophy though. It'll be a portal into a full-immersion music experience of SOTA caliber (and one well beyond the typical speaker installation no matter its cost). Four years ago when the CHA-1 was first conceived, market interest in such an unreasonable statement effort was mostly zero. Today there is a glimmer of hope that such an extremist machine might enjoy an appreciative reception by the few who not only can afford it—I sadly can't—but who recognize it for what it is: still well ahead of its time!
 
Crayon Audio website