Cayin iHA-6 Headphone Amp, iDAC-6 DAC, and iDAP-6 Digital Audio Player

REVIEW
by Chris Martens
Jul 18, 2019

In 2016 the Chinese high-end audio specialist Cayin Audio introduced two impressive personal audio components: the fully balanced iHA-6 solid-state headphone amplifier and its sibling, the fully balanced iDAC-6 hybrid solid-state/tube high-resolution DAC. In the U.S. these components sold for $699 each—a price point high enough for the components to be taken seriously, yet accessible enough for them to be considered relatively affordable. Later on, in 2017, a third Cayin i-Series component joined the group: the iDAP-6 digital audio player ($799). The iDAP-6 acts as a streamer/server/digital player that turns Cayin’s i-Series power trio into a complete high-end personal-audio music system.

The i-Series models share a common design theme featuring slightly wider than half-rack-width chassis sporting thick-walled, satin-finished, silver-aluminum cases. Cayin intends the components to be stackable—typically with the amp on the bottom, the DAC in the middle, and the DAP on top. The fit and finish of the components—not to mention their greater than 3kg weight per piece—makes them look and feel costlier than they actually are.

The iHA-6 headphone amplifier has balanced and single-ended analog inputs, and two sets each of balanced and single-ended headphone outputs. In fact, there are two single-ended 6.35mm headphone jacks, one optimized for low-impedance headphones and the other for high(er)-impedance headphones. There is also a left/right pair of balanced 3-pin XLR headphone jacks, plus a balanced stereo 4-pin XLR headphone jack.

Faceplate controls are straightforward and include a large illuminated on/off switch, plus three smaller illuminated pushbuttons: one for input selection, one to engage/disengage high-current mode, and one to select high or low master gain. The only other faceplate control is a large volume-control knob connected to a premium-grade ALPS four-channel rotary potentiometer. Cayin describes the amplifier circuit as a “quadruple amplifier with full discrete components and fully balanced design.” The circuit, says Cayin, uses “Toshiba audio-grade (K246) FETs in a differential input circuit” and a “push-pull amplification design with ultra-low on-resistance (HUF 76633) power MOSFETs at the power amplification stage.” The result is a muscular, wide-bandwidth, low-distortion, and low-noise headphone amp that can drive virtually any load.

Technically and sonically 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, and a pair of independent 5L25 5B K55750 Crystal oscillators. Additionally, the iDAC-6’s analog output buffer stage features a quartet of 6N16B tubes that, at the user’s option, can be switched into the DAC’s signal path or bypassed.

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 SPDIF, and optical SPDIF. Two sets of analog 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 iDAC-6 faceplate controls are straightforward. Three pushbutton switches allow users to select sources, timbre options (vacuum-tube or transistor), and line (fixed) or preamp (variable) outputs. A large rotary control knob, matching the one on the amp, does double duty as a volume control (when the DAC’s output is in preamp mode) or as a rotary/push-to-engage navigation control/menu item selector. Finally, there is a large, centrally positioned, back-tilted, 3.95-inch AMOLED display that shows the playback status of the DAC in real time. The end result is a capable and sonically refined DAC that provides a just-right amount of flexibility, without oppressively complicated set-up or adjustment options. (Just at press time, we learned that Cayin has plans to release a follow-up product to the iDAC-6 that is to be called the iDAC-6 Mk2.)

Finally, we come to the iDAP-6 digital audio player, which deliberately blurs the lines of distinction between streamers, servers, and conventional digital audio players with their own on-board music storage capabilities. Specifically, the iDAP-6 can support file sharing via WiFi or Ethernet for devices 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 ways to enjoy the player is to plug in your own SD memory card or USB music-storage device and then control playback proceedings via the iDAP’s sophisticated user interface.

The versatile iDAP-6 provides seven 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 SPDIF, and optical SPDIF. Generally speaking, the USB output is 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 DSD256, 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 pairs of challenging full-sized headphones (the Abyss AB-1266 Phi CC edition, the Final D8000, and the HiFiMan Susvara) and also with a set of revealing high-sensitivity earphones (the Campfire Audio Atlas).

From the outset, the sheer levels of power, articulation, 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, I suspect you might take them to be models selling in the $4000–$5000 range.

On a track that thrives on textural subtlety and timbral nuance, such as “Bon Soir” from Apricot Blossoms against a Sky [16/44.1], the Cayin amp and DAC answer the call with a deft and delicate touch. The track contains some beautiful, 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.

On tracks where rhythmic drive, power, and dynamic expression are called for, such as “Yesternow” from Miles Davis’ soundtrack for A Tribute to Jack Johnson [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.

The iDAC-6’s five digital filters proved useful, too, because they allowed me to 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 “Small Delay Sharp” filter more often than the others.

I attribute the Cayins’ strong performance partly to their strong and well-executed circuit designs, but also to the fact that Cayin chose a “let’s stick to the fundamentals” approach. Many manufacturers seemingly delight in piling features on top of features, but Cayin wisely understood that if you get the sonic fundamentals right, there really is 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 for use with my extremely sensitive Campfire Audio Atlas earphones.

Together, Cayin’s iHA-6, iDAC-6, and iDAP-6 form a powerful, articulate, and musically satisfying high-end personal-audio playback system whose sophisticated sound more than justifies the trio’s moderate price.

Specs & Pricing

iHA-6 Headphone Amplifier
Type: Balanced solid-state headphone amplifier
Inputs: One single-ended stereo analog via RCA jacks; one balanced stereo via 3-pin XLR jacks
Outputs: Two single-ended via 6.35mm headphone jacks (one optimized for low impedance headphones, the other for high impedance headphones); two balanced outputs (one via a L/R pair of 3-pin XLR jacks, the other via a 4-pin stereo XLR jack)
Frequency response: 10Hz–80kHz, +0/-0.5dB
THD+noise: ≤0.02%, 1kHz@32 ohms
S/N: Single-ended: ≥105dB (A weighted); balanced: ≥110dB (A weighted)
Power output: Single-ended: high current, 2 x 1100mW into 32 ohms; low current, 2 x 2200mW into 32 ohms; balanced: high current, 2 x 5000mW into 32 ohms; low current, 2 x 7000mW into 32 ohms
Dimensions: 240mm x 69mm x 252mm
Weight: ~3.8kg
Price: $699

iDAC-6 DAC/Preamplifier
Type: Hybrid solid-state/tube DAC/preamp
Tube complement: Switch selectable, 4x 6N1B valves at the buffer stage
DAC complement: 2x AKM AK4490
Inputs: USB, Optical SPDIF, coaxial SPDIF, AES/EBU
Outputs: Stereo single-ended variable (pre) or fixed (line) outputs via RCA jacks; balanced variable (pre) or fixed (line) outputs via dual 3-pin XLR jacks
File formats supported: PCM to 32/384, DSD to DSD128
Frequency response: 20Hz–30kHz, ±0.5dB
THD+noise: Valve: ≤0.8%; solid-state: ≤0.004%
S/N: Valve: ≥105dB (A weighted); solid-state: ≥110dB (A weighted)
Dimensions: 240mm x 69mm x 252mm
Weight: ~3.8kg
Price: $699

iDAP-6 Digital Audio Player
Type: High-resolution digital audio player
Inputs: WiFi, Ethernet, Bluetooth v4.1, SD card, two USB ports
Outputs: USB, I2S, AES/EBU, two SPDIF (one optical, one coaxial BNC)
File formats supported: DSF, DFF, SACD-ISO, FLAC, AIFF, WAV, APE, ALAC, WMA, MP3, AAC, OGG
Output formats supported: PCM to 32/384, DSD to DSD128 via DoP or DSD256 via I2S
Dimensions: 240mm x 69mm x 269mm
Weight: ~3.29kg
Price: $799