All righty then. Impressions for the iDAC-6 and iHA-6.
Disclaimer:
I'd like to thank Cayin for letting me have the opportunity to get a chance to demo the iDAC-6/iHA-6 stack for a week. It was really a pleasure to get a chance to hear it more carefully outside of a local Head-Fi meet.
The super short summary:
I love the iDAC-6, but I probably needed a more diverse set of headphones to really get a good listen of the iHA-6.
About me:
Since I acquired the STAX SRS-2170 in 2014, I've been exploring DACs a lot more since I no longer needed to search for an amplifier in the traditional sense. From the past few years of the hobby, only the LH Labs products, Audio-gd, as well as the Schiit Yggdrasil have left really positive impressions for me in terms of sound. I opted for the LH Labs products via their Indiegogo campaigns since, I'm guessing this is true for many crowd-funded campaigns, the idea sounded really nice on its first presentation, and on-paper. I'm not dissatisfied with their products for the most part, but they do have a sigma around here. The Yggy came out after I received the Pulse X Infinity DAC/amp anyway, and I didn't want to shell out a few grand for a DAC that couldn't fit on my desk and takes a week of on-time to sound at its best. But theeeen...
Enter the iDAC-6:
At $999, I think this DAC is an absolute steal for the money.
- It can play back pretty much any digital audio track you throw at it (16/44.1 to 24/384 DXD to DSD256)
- It's a fully balanced design so it gets the benefits of differential signaling
- It has a myriad of sound options you can switch to
- Versatile input/output options
The volume operation is similar to that of other multi-bit Delta-Sigma DACs I've seen, meaning you can use software or the volume knob to control the digital volume level (only on the pre-amp mode). Alternatively, you can set it to line-out mode, which is a fixed volume level (or basically maximum volume). It has the option to decode DSD in a true 1-bit fashion, but from the description
here, it looks like that's only possible through the coaxial digital input and not USB?
Anyway, I was using the USB input and I used the iFi micro iUSB 3.0 with the LH Labs LightSpeed 2G cable.
The DAC chip itself is the
Asahi Kasei Microdevices' AK4490. Most of the DACs I've heard use an ESS Sabre DAC of some sort, so hearing a well-implemented non-ESS DAC was a nice change of pace for me. I had previously listened to the iDAC-6 at a local Head-Fi meet, but it was paired with the iHA-6 on a different setup from my usual environment. Because of this, I didn't know what the iDAC-6 would sound like on my system and boy was I surprised. Its overall sound is super smooth, balanced, punchy bass, and natural-sounding overall. Absent is the the "Sabre glare" brightness that I'm used to hearing from ESS DACs. Even though I find the Pulse X Infinity to greatly reduce that sound, comparing it with the iDAC-6 made it really apparent to me that it's still there. The soundstage presentation and imaging of the iDAC-6 sounded pretty spherical to me, having about equal dimensions of height, width, and length, but it was on the smaller side to me. Instrument separation was likewise good, but not quite up to spec with the Pulse X Infinity.
The one major negative experience I had with the iDAC-6 was that it includes muting relays(?) inside of the device that activate whenever audio is stopped being transferred to the device (you can hear the unit making clicking sounds when this happens). When audio is resumed, it takes half a second for the relays to switch off, which means you will get a delay in audio to your speakers/headphones. Especially for watching videos and/or editing audio, this is a really annoying thing to have since you would need to rewind the video/audio track few seconds to get back to where you left off.
In terms of the different sound options you can toggle with the iDAC-6, I preferred the "transistor" setting over the "tube" one since the "tube" one sounded a bit more like the ESS DACs. Compared to the Pulse X Infinity's digital filters, I had a harder time picking out differences with the 5 filters offered in the iDAC-6. I preferred the sound with the "S.D. Sharp" or short-delay sharp digital filter over the other ones as it sounded the smoothest to me and the imaging was more well-defined. "Sharp" was the next best for me, and I somehow didn't like any of the 3 "slow" filters.
From my limited knowledge of digital filters, the "short delay" filters might be minimum phase filters in which the pre-ringing energy of transients is delayed until after the signal. These types of filters are usually seen in "fancier" or more expensive DACs, so having them in this $999 DAC is really nice for users to experience. Minimum phase filters are often associated with sounding more "natural" and having more precise imaging. As for "slow" versus "fast," I'm pretty sure that indicates how much the digital filters attenuate signals at the Nyquist frequencies: "slow" meaning it allows some aliasing signals to enter the passband frequencies past the Nyquist frequency at the convenience of having less ringing occur in the impulse response; "fast" meaning it attenuates signals very close to the Nyquist frequency at the cost of having much more ringing in the impulse response. Typically ringing is bad, as is pre-ringing, so it sounds like the ideal filter would be "S.D. Slow" or short-delay slow. I haven no idea what the fifth filter does though, "Super Slow."
Conclusion:
Considering what the iDAC-6 sounds like, what it can do, the versatility of inputs/outputs it has, how much you can change its sound, and its price, it would be hard for me not to recommend this fantastic DAC. If I didn't already have a good DAC system with me, I would probably buy the iDAC-6, and that's something that doesn't happen to me often. If you get the chance, I would highly recommend giving this a listen!
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iHA-6:
I didn't get much of a chance to give this a close listen, but from when I did listen to this, I was using either the AKG K701 (hard-wired with a balanced cable) or a touring Kennerton Vali, both of which are fairly low impedance headphones. Because of their low impedance, I did a bit of comparisons between the normal mode and high-current modes that the iHA-6 offers. As I expected, I preferred the high-current mode better for these headphones since it seemed to make the imaging a bit more precise, as well as the bass having more authority and definition. I hear similar things when switching from balanced to unbalanced, and that seems consistent from my experience of balanced versus single-ended overall.
Gain....I'm not really sure in what situation you would need to toggle this switch, perhaps with an low-sensitivity headphone playing quiet music, but I pretty much didn't need to turn the volume knob a few millimeters before it got too loud for me on low gain. Looking at the specifications, the iHA-6 outputs a whopping maximum of 5 W per channel via balanced outputs on high-current mode (1.1 W via single-ended). 1 W is plenty for my listening habits.
I really like the 3-pin headphone output ports on the iHA-6 since they double-up as 6.3 mm headphone outputs in the middle; that's just freaking awesome.
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Just some general gripes:
- The stack gets really, really hot. More so for the iDAC-6 than the iHA-6, but when I was packing them up to give to the next person on the tour, I turned off the units and tried to pick them up after waiting a couple of minutes. Holy, they were still burning hot; like trying to hold a single-cup hot Starbucks coffee without a cardboard sleeve.
- The corners of the units are pretty sharp, just F.Y.I.
Thank you Cayin again for letting me be a part of the tour!