Cayin iDAC-6 and iHA-6: A Dynamic Duo Page 2


iDAC-6 ($999)
The iDAC-6 is a versatile D/A converter, jam-packed with features despite its diminutive measurements of less than 10 inches by 10 inches square. This is a true balanced DAC with XLR and RCA outputs along with all the expected inputs: coaxial, optical, AES/EBU, and USB. The USB input is an up-to-the-minute XMOS implementation capable of handling single and double-rate DSD as well as PCM up to 32-bit/384kHz, while the "legacy" inputs top out at 24-bit/192kHz. Toslink is supposedly limited to 176.4kHz but I got 192kHz working just fine, though I realize this is pushing the limits of the format and may vary from unit to unit or even cable to cable.

One thing the iDAC-6 won't do is handle headphones directly. Since Cayin designed it to be paired with their matching headphone amp, there's no headphone jack on board, though it does work as a preamp via defeatable digital volume control. I notice a trend where a lot of newer DACs have a headphone output built in even when a matching dedicated amp exists in the same line—that seems needlessly redundant, and I'm glad they left it out in this case.

Build quality on this thing is very high. The uncommonly-thick enclosure has no exposed screws to speak of, making it more challenging than usual to access its juicy innards. The front panel is based around an LCD display which shows all manner of useful info—active input, incoming sample rate, PCM or DSD, etc. Cayin surely could have saved some dough by making the LCD a more typical flush-mounted/flat design. Instead, they gave it a bit of a cutout and mounted it at a slight angle. It's hard to explain but very obvious in the pictures. This complexity makes it more visually interesting while aiding legibility when viewed from a downward glance—as is likely to be the case with a desktop component.

I just can't stress enough how well-built and attractive this thing is for the price. I have it sitting on my desk next to an Auralic Vega and a Calyx Femto—both significantly more expensive devices—and the Cayin does not look the least bit out of place. The only real giveaway is the volume knob which looks nice but feels merely adequate. My review unit had a somewhat "scratchy" action until I adjusted it using the set screw. On a multi-thousand dollar device I would expect a solid block of milled aluminum, which is exactly what Auralic gives us on their device, but for a $999 unit I suppose this is acceptable.

Actual D/A conversion itself is handled by a pair of 32-bit AKM AK4490 "Verita" chips operating in dual-mono mode. AKM's flagship AK4490 is a fairly recent design, having just been launched within the past couple of years, and has turned up in some rather interesting gear—upscale kit such as Lindemann's Musicbook 15, the top dog AK380 DAP from Astell&Kern, and the new Esoteric N-05 DAC/streamer. It also appears in the less extreme Teac UD-503 which is priced identically to the Cayin offering.


Unlike any of those models, the iDAC-6 offers your choice of tube or solid state outputs. These are selectable via the very straight forward menu system controlled by a combination of spinning and pressing the volume knob. The analog output stage is based around the Texas Instruments OPA604 and OPA2604 FET opamps, while the tube option adds a quad of 6N16B miniature tubes as an additional buffer stage. So I wouldn't call this a "pure" tube DAC, but neither are many other designs. For example, my old Cary 303/300 "tube" CD player was touted as having a selectable tube output stage, but in reality used the tubes as a buffer just like the iDAC-6. This is in contrast to devices such as the Audio Note DACs which use tubes for actual voltage gain. Neither style is right or wrong, it's just a different approach.

Worth noting is the fact that only the RCA output can switch to pure solid-state, while XLR requires the tube section to be engaged at all times. Output voltage is a (slightly) higher than average 2.2V on the RCA output and 4.4V for XLR. In case you were wondering, the tubes are not user replaceable on this model. This means no tube rolling, though Cayin seems confident they've already provided optimal glass. I'm happy with that based on the sonic result (as I'll soon discuss) but my concern relates to longevity—all tubes eventually run their course, effectively giving this DAC a finite and somewhat predictable lifespan. Cayin advises these particular valves are rated for nearly 10,000 hours worth of use. That equates to 3 hours of listening per day, every single day, for nearly a decade. If we're more busy and only manage 10 hours of listening per week, the estimate extends to nearly 2 decades. That seems reasonable to me, though with lifespan in mind I do try to power down when I'm done listening. On the other hand, someone who sits at a computer all day (coding, graphic design, whatever) listening to music, day in and day out, might find this more worrisome. Under those circumstances I could see this DAC getting used 40 to 60 hours a week, which drastically lowers the life expectancy. Perhaps not a common situation but something to consider.


The iDAC-6 allows user selection of 5 different digital filters for tweaking of the sound. These differences are very subtle, at times impossible to discern. After extensive listening I've identified the proprietary AKM "Super Slow Roll-Off" filter as sounding the most natural to my ears, followed by "Minimum Delay Sharp Roll-Off" which is also known as an "apodizing" filter. The other 3 options don't sound quite as organic though, again, this is very far from a night and day difference. Still, between the filters and the optional tube buffer, there's enough wiggle room to account for different sonic preferences.

I installed the device in my desktop rig, paired with a MacBook Pro running an up to date copy of Audirvana Plus. With both outputs active simultaneously, I was able to feed the matching iHA-6 headphone amp as well as my Adam Audio F5 active monitors without resorting to tactics like splitter cables. I appreciated the volume control as Adam rather inconveniently placed their volume knobs on the rear panel for this model.


Using XLR out and therefore tube output mode, and my preferred filter selection, the resulting sound via the Adam monitors was what I'll clumsily refer to as "luscious". While generally neutral and very capable in terms of microdetail, I did detect a slight tilt towards warmth, particularly in the midrange. There was a thickness of note that is not always present on today's ultra-incisive DACs. Vocals oozed with emotion, and I mean that in the best possible way. Despite being a relatively affordable monitor, the F5 is highly capable of bringing out the passion of a performance. Thus, whether listening to Jacintha or Sinatra or even Eddie Vedder, this system excelled at sounding believably emotive. The top end also benefited from a great deal of air and a distinct lack of troublesome grain. Bass performance was clean but that's about as far as I could tell in this context, the modest woofers of the F5 being the limiting factor here.

Moving to the big setup in my living room, the little Cayin took center stage among some far larger components. I've essentially had two systems running concurrently for some time now: one path uses the Egglestonworks Emma speakers driven by a Parasound Halo A21 amplifier, with the other pairing a set of Usher Dancer Mini One DMD towers with a NuPrime ST-10 amp. These are two very different systems, both enjoyable in their way but very distinct from one another. The Usher/NuPrime combo is incisive and refined to the point of being extremely demanding of source material. The Eggleston/Parasound setup is what I'd call musical and somewhat forgiving, though not overly so. I was able to insert the iDAC-6 in the mix driving both systems directly and I definitely learned a thing or two in the process.

First off, I was a tad disappointed in the volume control system. Not that I noticed a drop in sound quality due to digital attenuation (a problem common to many other DACs using digital volume control schemes) but rather in practical terms. The iDAC-6 only gives 32 steps worth of volume control to go from silent to full scale. That's not very many, and at times I found myself wishing for more intermediate steps. This wasn't much of an issue in my nearfield listening, for whatever reason, but became somewhat obnoxious in my bigger system. I'm not sure why this limitation exists—the AK4490 chip has onboard volume control with 256 steps in .5dB increments, but perhaps Cayin bypassed that function and used their own implementation. Again, the volume solution is quite transparent as long as you find the adjustment range adequate to dial in your system. Personally I think I'd end up using a dedicated pre-amp if the Cayin took up long term residence in my big system, which would solve this issue and give the added benefit of remote operation (the Cayin has no remote).

Volume control gripes aside, I was very pleased with the sonic results here. The tube buffer and the different filters gave just enough variation to make the Cayin pair well in both systems—a task not likely accomplished by a less tweakable DAC. I used the fairly traditional "Linear Phase Slow Roll-Off" filter paired with solid-state output for the Parasound/Egglestonworks combo. It brought some welcome get-up-and-go to this easygoing duo, increasing the sense of transient snap and overall excitement. My jazz and classical experience was much improved in this configuration, which subsequently became more suitable for critical listening.

For the NuPrime/Usher combo I wanted just the opposite—something to mellow out the high-strung, analytical sound. I found just the thing using the tube output plus the "Super Slow Roll-Off" filter, which collectively added a measure of tonal weightiness plus a graceful smoothing of unwanted shimmer on bright recordings. This system already excelled at playing Reference Recordings and similarly high quality material, but now it could handle Rudy Van Gelder Blue Note remasters without drilling my ears out. Remember how I said the changes in filters were subtle? Well, the difference between tube and solid-state output is also fairly minor, but collectively it does add up to something more significant. It won't turn an HD800 into an LCD-2, but might just help you enjoy both of those headphones if you're on the fence about certain aspects of their performance.

I've heard much discussion about the supposed "Sabre sound", or how all Delta-Sigma converters have the same character, or how Wolfson DACs tend to be warmer than this or that alternative. I consider all such talk nonsense, and my experience with the iDAC-6 confirms this opinion. That's tantamount to saying all silk-dome tweeters sound alike, or every Sennheiser headphone has the same house sound—both may be somewhat true in small doses but neither concept scales all that well in the face of numerous counterexamples.

The AK4490 certainly seems to be a high-performance DAC, and using a pair of them in dual-mono mode is even better. However, it's clear to me that the other aspects such as output stage and digital filter make bigger contributions to the final voicing of a device. If this one unit can be such a digital chameleon, what's to say two different designers won't get vastly different results based on their unique approaches? Using the same DAC chip in no way guarantees a similarity in final sound.

That said, the Cayin iDAC-6 is a serious contender in its price bracket. I don't recall ever coming across a more tastefully designed, well built DAC that can do everything the little Cayin does in terms of sonic malleability. If your sensibilities demand a neutral, incisive sound with very little editorialization, the iDAC-6 can do that as well as any other in its class. If you lean more towards full-bodied, slightly euphonic playback, the iDAC-6 can do that as well—even switching from one to the other on a song by song basis if you so desire. This makes it uniquely versatile in my experience, and thus easy to recommend.

Next up, I moved the iDAC-6 into my headphone rig, where I paired it with a number of different amps and cans. Which leads me to page 3....

Cayin - Zhuhai Spark Electronic Equipment Co., LTD
9 Lianfa Rd, Shuanglin Zone,
Liangang Industrial Park, Zhuhai City
Guangdong Province, China

tony's picture

Hello Mr Grandberg,

There seems to be a rather intense interest in Tube Rolling now-a-days.

Your reviewing one of these little headphone amps ( along with a box of Tubes ) would make for some fascinating journalism.

I suppose, then, that you'd be reviewing the hobby of Tube Rolling as well as one of the Amps that has the capability.

I could point at the Polish Felikes, the Woo, the various Schiit Amps, the Garage1217, the Bottlehead stuff ( that Tyll built and seems to love ).

The Garage1217 postings on Head-fi read like each triode gives the amplification a unique sound quality, almost like buying a whole different amp.

Apparently the Felikes is the latest "HOT" item.

Betcha someone would "loan" you an Amp and a box of Tubes.

Thanks for all your insight, being featured on Innerfidelty is a resume builder.

Maybe Tyll will show you how to do Video Reviews that folks with an iPhone will & can watch, it's the next big thing.

Tony in Michigan

ps. Stoddard just went on another Rant about the Newport Show

John Grandberg's picture
Cayin has just the thing in the upcoming HA-1A mk2. It's got a pair of 12AU7's driving EL84's along with the somewhat unusual (at least in my experience) 12DT5 for rectification. Very easy to roll tubes - I've got one here and have been rather enjoying myself, though I leave the 12DT5 alone for now. With the right tubes the amp is very competitive, superior in my opinion to the Woo stuff for example. I'll have more to say about it down the road.
tony's picture

Geez, Sam Telig had one of these things, back in 2006. It's been around for a loooooooong time now. How'd we miss it?

Even has a couple of Watts for speakers, ( first watt will give 86db. on a pair of Pro-Ac Tabletts).

Nice find John, good work!


Tony in Michigan

ps. the darn thing even has a impedance matching selector for headphones.

I wonder what the mk2 feature set will be? I'll be following along.

R-Val22's picture

I have been looking at the Sennheiser HDVD800, but after reading your review you have piqued my interest. I cannot find a dealer for the Cayin however, Could you help? And would you choose the Cayin over the Sennheiser for the HD800-S and HD700s?

John Grandberg's picture

I'm told Cayin is working on getting more local distributors (I'm assuming here that you live in North America like me) but for now there's one in Canada that has a shipment of this new stuff on the way:

I don't particularly care for the HDVD800 and I'd much rather choose the Cayin stack - or any number of other combos - for the money.

tony's picture

I heard the HDVD800 driving the HD600 & HD800, at a headphone meet, I very much liked it. It has a DAC that can't be bypassed, ( no way to put an EQ between the Amp and DAC (which I need to do for my elderly hearing tapering off above 8kz.)

At the very same meet I heard a Valhalla 2 ( tubed up with super Russian tubes ) I should've bought that Amp but never got around to it.

If I don't get around to Tube Rolling I'll simply stay with the Asgard 2, for the money, it's Gold.

Tony in Michigan

R-Val22's picture

I want a balanced out so if I was to go Schiit It would be the Mjolnir2/Gungnir Multibit, but tube rolling would be a whole new hobby

tony's picture

I think you are right, tube rolling has near limitless possibilities for the exploring of sound quality.

Tony in Michigan

R-Val22's picture

What that include the Mjolnir 2/Gungnir Multibit?

John Grandberg's picture
Haven't heard those newer ones yet. I definitely like the Cayin more than original Mjolnir and Gungnir though.
tony's picture

It looks like the Pound is dropping to 1985 lows, making British gear more affordable for buyers paying with US Dollars.

Mojo buyers win.

Tony in Michigan

John Grandberg's picture
...if prices reflect the drop right away or not. Not long ago, the Dollar was doing well against the Euro, the Violectric USA distributor gave a 15% discount to account for that (still in place at the moment). Yet most imported gear remained the same price. I guess if a distributor bought high and is sitting on a mountain of gear, they don't want to sell low. Which is where small "direct to customer" situations work out better.
tony's picture

Guys like TTVJ could buy up mucho Vinyl Gear ( as in Michell Gyrodecks ) as well as LS like the LS3/5a and the like. Brit prices haven't been this low since the mid 1980s.

Gotta have "Cash on the Barrel head" to work this but it can be verrrrry profitable.

Tony in Michigan

ps. I think I'm paying .50 cents per pound wt. to container Air ship from England to DTW ( Michigan ) , J.V.Carr clears the stuff thru Customs. ( I stopped doing Audio Stuff 30 years ago, I ship Car stuff )

R-Val22's picture

Hi Mr. Granderg,I contacted audionaton and bought the Cayin combo. I have both a Win 7 and Win 10 computer and I'm having a problem installing the drivers for the dac. I followed some recommendations that were made on a thread on Head-fi and posted my current situation on there as well, but I'm hoping someone can help me out on this problem. I'm burning up not being able to hear them.

John Grandberg's picture

I missed this comment until today. I'm not sure what to suggest - I have 2 Windows machines (8.1 and 10) both working fine with the supplied drivers, as well as a MacBook and a Linux device from Aurender. All of mine work fine with no issues.

The only thing I can think to do is make sure you remove all older USB drivers. That has caused me some grief in the past when I didn't realize I had something else already installed from a different device. Or perhaps you already got it sorted by now? Again, sorry for the delay.

norsemen's picture

It was a great review to read John!

Iha-6 hasn't been listed on WoF yet. Will WoF be updated soon?

pcdvd's picture

Hi, John.
Can you please compare iDAC-6 + iHA-6 and DAC-10H?