As far as both technical and sonic personae go, the iDAC-6 is the perfect complement to the iHA-6. Like the amp, the DAC is a fully balanced design that features dual AKM AK4490 DAC devices (one for each channel), a four-channel active low pass filter system said to “fully explore the potential of the two DAC chipset”, and a pair of independent 5L25 5B K55750 Crystal oscillators claimed to “synchronize DSD and PCM decoding.” Additionally, the iDAC-6’s analogue output buffer stage features a quartet of 6N16B valve’s that can be switched into the DAC’s signal path or deliberately bypassed, depending on the listener’s tastes and preferences.
All the expected digital decoding capabilities are present and accounted for including PCM up to 32/384 and DSD up to DSD128. There are four digital inputs to choose from including USB, AES/EBU, Coaxial S/PDIF, and Optical S/PDIF. Two sets of analogue outputs are provided: one stereo pair of balanced outputs via 3-pin XLR connectors and one stereo pair of single-ended outputs via RCA jacks.
As with the iHA-6, the faceplate controls of the iDAC-6 are straightforward and easy to use. A set of three push-button switches support, respectively, Source selection, Timbre selection (Vacuum Tube or Transistor), and Line (fixed) or Preamp (variable output) selections. A large rotary control, matching the appearance of the one found on the amp, serves double duty as either a volume control (when the DAC’s output is in Pre mode) or as rotary/push-to-engage/select menu navigation control and menu item selector. The key menu driven options include Phase settings (Normal or Inverted) and Filter selections (options include Sharp, Slow, Short Delay Sharp, Short Delay Slow, and Super Slow filter settings). Finally, there is a large, centrally positioned, and slightly back-tilted OLED display window that shows the playback status of the DAC in real time (complete with information on the file type being played). The end result is a capable and sonically refined DAC that provides a just-right amount of flexibility, without overwhelming the user with a bewildering plethora of configuration options and arcane adjustment settings that probably the designer alone could understand or explain.
Last but not least, we come to the newest member for the Cayin trio: the iDAP-6 digital audio player. The iDAP-6 is a multi-faceted player that deliberately blurs the lines of distinction between streamers, servers, and conventional digital audio players with on-board music storage capabilities of their own. I say this because the iDAP-6 can support file sharing via WiFi or Ethernet for devices, notes Cayin, networked “through Samba, DLNA, and Airplay.” Similarly, the iDAP-6 can “transmit or receive through dual Bluetooth v4.1,” and supports, “Bluetooth remote control profile.” However, one of the simplest and easiest ways to enjoy the player is to plug in your own SD memory card or USB storage device loaded with music files and then to control playback proceedings via the iDAP’s own sophisticated user interface, which Cayin describes as a “multi-lingua custom designed UI” via the built-in 3.95-inch AMOLED display screen. The screen shows Album Art, music information, and the unit’s various control menus “in a clear and effective presentation.”
Indeed, this latter option is the one I used in my listening tests, by connecting a spare 2TB music library drive I had on hand to one of the iDAP-6’s USB ports, then using menu controls to read the files on the drive and to load music library information. One thing that is very nice about this approach is that, once you’ve select a file you wish to play and have initiated playback, the selection’s album artwork and other important playback data (for example, information on the file format being played, play/pause status, or the run time of the track in play) automatically appear on the large, colourful display screen. Even from some distance away, you can tell at a glance what material has been selected and is presently running.
The versatile iDAP-6 effectively provides the following inputs: Bluetooth, WiFi, Ethernet, a full-size SD card slot, and three USB ports (USB storage devices are treated as OTG sources numbered 1 through 3). Digital outputs include USB, I2S, AES/EBU, Coaxial S/PDIF, and Optical S/PDIF. Generally speaking, the USB output is arguably the most versatile as it supports both PCM files up to 32/384 and DSD files via DoP up to DSD128 (granted, the I2S interface can go up to DSD 256, but I2S is not an input commonly seen on most DACs—yet).
Given this overview, let’s now talk about how Cayin’s i-Series threesome actually performs. For my tests, I used the Cayin components with three very high performance (though admittedly challenging to drive) headphones: the Abyss AB‑1266 Phi Edition CC, the Final D8000, and the HiFiMAN Susvara. I also ran the components through a mid-priced but very revealing headphone, the Cleer Next, and with the superb Campfire Audio Atlas earphones (mostly in order to evaluate the Cayin’s ability to drive very high sensitivity earphones).
From the very start, the sheer levels of power, articulacy, and overall control offered by the iHA-6/iDAC-6 pair simply floored me. Candidly, if you listened to these components without knowing their identities or prices, my guess is that you might take them to be components priced north of, say, $4,000-$5,000, judging purely by the sound quality on offer. On a track that thrives on textural subtlety and timbral nuance, such as ‘Bon Soir’ from “Apricot Blossoms against a Sky. Chang Jing. Guzheng” [10th Anniversary of Rhymoi, 2001–2013, Rhymoi, 16/44.1], the Cayin amp and DAC answer the call with a deft and delicate touch. The track contains some beautiful and intimate-sounding cello passages and the Cayin pair captures their incisive transient sounds and almost vestigial shadings of tone and expression with impressive grace and realism. As I listened to the track I found analytical thoughts were quickly pushed aside as I became caught up in the sheer richness and desirable intricacy of the sound.
On tracks where rhythmic drive, power, and dynamic expression is called for, such as “Yesternow” from Miles Davis’ soundtrack for A Tribute to Jack Johnson[Columbia, DSD64], the Cayin pair again proved its mettle with a sound that captured the propulsive groove of the music; the sometimes ‘in-your-face’ dynamics of the bass, drums, and trumpet; and the at times mysterious, otherworldly vibe of the soundtrack.
Finally, the iDAC-6’s five digital filters proved useful, too, because they allowed listeners to compare and choose from among five subtly different approaches to the overall sonic presentation. Which filter(s) you prefer will largely be a matter of taste or a function of the music you choose, though I personally used the ‘Short Delay Sharp’ filter more often than the other (your mileage may vary, of course).
I attribute this strong performance partly to Cayin’s strong and well-executed circuit designs, but also to the fact that Cayin chose a “let’s stick to the fundamentals” approach to these designs. Many manufacturers seemingly delight in piling features on top of features in their products, but Cayin wisely understood that if you get the sonic fundamentals right, you really have no need for additional ‘gongs and whistles’.
I was delighted, too, to find the iHA-6/iDAC-6 pair had sufficient transparency and power to take full advantage of my reference Abyss, Final, and HiFiMAN headphones, which is saying a mouthful (especially in the case of the very difficult to drive HiFiMAN Susvara). At the same time, with its gain setting backed down to ‘Low’, the iHA-6 proved quiet enough to be used with my revealing Campfire Audio Atlas earphones.