Calyx Audio FemtoRecommended Reference ComponentThe DAC market is hot, with more 24-bit/192kHz DACs available right now than you can shake a stick at. SoundStage! Network reviewers have evaluated many of the newest DACs and have found most of them to be quite good, but in the last year three DACs have stood out as being significantly better than the rest: the Simaudio Moon Evolution 650D ($9000 USD), which Doug Schneider reviewed last March and which was included in the Recommend Reference Component listing in April; the Meitner Audio MA-1 ($7000), reviewed last May by Uday Reddy, and recognized as a Recommended Reference Component in November; and the Calyx Audio Femto ($6850), which Doug reviewed last September and which is this month’s Recommended Reference Component.

The Femto is beautifully built. Its all-aluminum case, measuring 17"W x 4"H x 16"D, is exceptionally well finished and very attractive. It’s the largest DAC Doug has seen, as well as the heaviest at some 40 pounds. On its front panel is a striking glass window framing an orange-tinged display that shows the incoming sampling frequency, the input and digital filter selected, and the volume level (if you choose to use it that way). On the rear are a plethora of digital inputs: two coaxial, two AES/EBU, two optical, one BNC, and one USB, all supporting resolutions up to 24/192. The remote control is designed and built to the same high standard as the main case.

Calyx Audio Femto

At the heart of the Femto’s circuitry are dual Sabre Reference ESS9018 DAC chips (one per channel) and ultra-low-jitter "femto" clocks, which designer Seungmok Yi says were "borrowed" from military and aerospace GPS technology (one femtosecond is one quadrillionth of a second, or 0.000000000000001s). According to Yi, Calyx products are not "voiced." Rather, the design goals for the Femto were simple and objectively achieved: reduce noise, distortion, and timing errors to an absolute minimum. Two of the measurable byproducts of this approach are a THD+noise of less than 0.0003% at 1kHz, and a balanced-output signal/noise ratio of 130dB (A-weighted).

Doug found the Femto’s appearance, build, and sound quality to be beyond reproach, bettering, by a significant margin, Calyx’s own DAC 24/192 ($1950), which he also reviewed (on SoundStage! Xperience), as well as every other digital source product he’s heard. As he said in his review:

"Whereas Calyx Audio’s DAC 24/192 was a fine product for its price, it had flaws that precluded me from giving it an unconditional recommendation. The Femto, on the other hand, bowled me over, despite its costing 3.5 times as much. I welcomed its sterling casework, superb styling, and rich feature set, but I was most taken aback by its spectacular sound, which, though cut from the same cloth as the DAC 24/192’s, was superior in a number of ways. In particular, the Femto’s high level of resolution, without sacrificing musicality or long-term listenability, was inspiring with hi-rez recordings, and a revelation with standard-rez fare. . . .

"The Femto . . . [is] a more developed, fully mature product that has left me with nothing to quibble about, aesthetically or cosmetically -- something that happens seldom. And even if the Femto can’t be considered cheap by any measure, it’s worth the asking price for anyone who wants a statement-grade DAC."

Calyx Audio Femto

For a company to distinguish itself in the crowded DAC marketplace is difficult -- to do so, that company must offer a product that’s significantly different from and/or a cut above the rest. South Korea’s Calyx Audio did just that when they introduced the Femto -- a standard-setting DAC that betters pretty much everything else out there in terms of looks and sound, and that can be used as a benchmark against which to judge other DACs at any price.

Manufacturer contact information:

Calyx Audio
Digital & Analog Co.
4F, Bohyun Building
1458-4 Gwanyan-dong, Dongan-gu, Anyan-si
Gyeonggi-do, 431-060
South Korea