Tiny and Mighty
The AudioQuest DragonFly is to high end audio what Tiny Mighties® Magnets are to a refrigerator. Both are very small and pack a big punch. In fact the DragonFly is half the size of the EMM Labs logo on top of the DAC2X. It's crazy to think both the DAC2X and the DragonFly are asynchronous USB DACs but the DF also features analog volume control! Before continuing I must say the DAC2X is a much better DAC that's in another league compared to the DragonFly. I only mention these two DACs together as both the price and size are at opposite ends of the continuum but the sound quality differences between the two are not complete opposites. Plus, such a comparison makes for a review full of suspense. Readers skipping this paragraph are likely scanning this review for the nonexistent sentence where I declare the $250 DragonFly the best DAC ever and far better than the $15,500 DAC2X. Unfortunately the ADD stricken readers will be in a self imposed suspense for quite awhile seeking a conclusion I clearly will not write. One more time for the record, the $15,000 EMM Labs DAC2X is unequivocally in another class above the $250 AudioQuest DragonFly. Anyone attempting to twist these words or read more into this review than what I'm actually saying is simply trolling.
AudioQuest worked extensively with the "Godfather" of high end USB audio Gordon Rankin to design the DragonFly. Internally the DF contains 107 components on a 0.6" x 1.7" four layer board including several regulators and custom capacitors. Externally the DF has only a USB connector, a 3.5mm (1/8") mini jack for analog output, and an illuminated dragonfly to indicate sample rate. Despite its simplistic external design the DragonFly has some advanced features to please both headphone listeners and those using the DAC only. One of the most surprising features of the DF is its digitally controlled 64-position analog volume control. The vast majority of devices anywhere near this price use digital volume control. This 64-position volume control can be used in variable mode where the user adjusts the level up or down based on desired output or the volume control can be set to unity gain in fixed mode. In fixed mode the analog volume control set to its maximum level much the same way as digital volume controls in software applications are set to 100% so as to not reduce bits before outputting a digital signal to a DAC.
A device with both fixed and variable output can be a skosh confusing in systems that already have one or more volume controls. In addition the DragonFly's output is controlled via software which introduces an extra layer of confusion for the unlearned music aficionado. Fortunately a little education can go a long way. Users should understand the DF's analog output level is controlled by the operating system's main volume control. However, things aren't as simple as sliding this main volume control left, right, up, or down. The best way to control volume and maintain audio quality depends on the operating system and the playback application in use.
Scenario 1: Mac OS X Computer > iTunes > DragonFly > Headphones
I recommend setting the iTunes volume to its maximum level and adjusting the audio output level with the main OS X control on the keyboard or the top OS X menu bar. The OS X main system volume is the sole volume control recommended to maintain the best audio quality with the DragonFly. This system volume directly controls the analog attenuator within the DF. Whereas the volume slider within iTunes is only a digital volume control and has no control over the 64-position attenuator in the DragonFly. If the iTunes slider is used to control volume the audio output to the DragonFly will no longer be bit perfect. This is because digital volume controls reduce the number of bits to reduce the output level.
Scenario 2: Mac OS X Computer > iTunes w/ Amarra > DragonFly > Headphones
Amarra volume control is similar to the iTunes volume control. Therefore I recommend setting the iTunes / Amarra volume to its maximum level and adjusting the audio output level with the main OS X control on the keyboard or the top OS X menu bar. The same as Scenario 1 above.
Scenario 3: Mac OS X Computer > iTunes w/ Pure Music > DragonFly > Headphones
Pure Music can operate in two different modes. One mode is identical to the above Amarra/iTunes and plain iTunes and the other mode is completely different in that Pure Music forces the iTunes volume slider to control the OS X system volume thus it controls the 64-position analog volume control in the DragonFly. I recommend using this second mode that controls the analog DF volume. To use this mode enter Audio Setup in Pure Music. Make sure AudioQuest DragonFly is selected as the Output Device. Then select the boxes for Volume and Mute to the right of "Allow Device Hardware Control If Supported" (image ). Click Apply Changes at the bottom of the Audio Setup window and Pure Music will restart in the preferred volume control mode.
Scenario 4: Mac OS X Computer > Audirvana Plus > DragonFly > Headphones
Audirvana Plus is a little different than the other applications. Audirvana Plus is capable of three different modes plus a few different configurations within each mode. The easiest way to get the best sound quality from the combination of Audirvana Plus and the AudioQuest DragonFly is to set the Audirvana Plus Audio Volume preference to DAC only (image ). Once this is set A+ will control the analog attenuation no matter what other volume options are adjusted. To take A+ to another level I recommend enabling the four Audio System references of Exclusive access mode, Direct Mode, Use max I/O buffer size, and Integer mode (image ). once this is complete the Audirvana Plus volume control only adjusts the DragonFly's 64-position analog attenuator without touching the main OS X system volume control. In fact the main system volume control has no effect on the DF in this mode with these options selected.
Scenario 5: Windows Computer > JRiver Media Center > DragonFly > Headphones
JRiver Media Center on Windows has the ability to control the main operating system volume with the application's volume slider. Thus, JRMC can control the DragonFly's 64-position analog attenuator with this volume slider. I recommend setting JRMC to use this configuration for the best audio quality when using the DragonFly. In the main JRMC window right click the speaker icon to the left of the volume slider. The pop up menu will allow selection of System Volume (image ). Once this is selected the JRMC volume slider controls the DF's analog volume level. It's very simple. While in this configuration area I also make sure the other volume levels are set to 100. To do this I select Application Volume and Internal Volume from the same right click menu and check the slider positions. If they aren't at 100 simply slide the volume over all the way to the right. Then click back to System Volume and make sure the level is far less than 100 as this is the actual volume output level.
Scenario 6: Any computer, operating system, and playback application > Powered Speakers
All the above information holds true for powered speakers. However, most if not all powered speakers have volume controls of their own. Users will have to experiment with the DragonFly volume control and the speaker's volume control to see which one not only sounds better but which one is most convenient. Many speakers place the volume knob on the rear of a single speaker. This position is far too inconvenient for me. The sound quality would have to be much better for me to consider using a rear volume control.
Scenario 7: Any computer, operating system, and playback application > Preamplifier > Amplifier > Loudspeakers
There are a couple items to consider when connecting the DragonFly to a preamplifier. First is the DF volume should be set to its maximum level / fixed output position. The methods above are identical for configuring the DF volume for headphones and a preamplifier. Second, both OS X and Windows sounds effects should be directed way from the DragonFly. The following screenshots display this configuration setting on Windows (image ) and OS X (image ).
In addition to an advanced volume control the DragonFly features asynchronous Class 1 USB Audio using the Streamlength™ protocol and dual fixed master clocks. This is a big deal. Industry leading asynchronous technology in a tiny $250 DAC was unheard of until the introduction of the DragonFly. What exactly is Class 1 USB Audio? This question recently came up on the CA forum and is one that many people are afraid to ask for fear of looking stupid in front of the world. USB Audio classes are frequently confused with the standard USB protocols such as USB 1.1, 2.0 and 3.0 referred to as Low/Full Speed, Hi-Speed, and SuperSpeed respectively. These USB protocols are what everyone has seen on the labels of external hard drives for many years. USB Audio Classes for the purposes of this review are like a subset of the USB Standard Specifications except the Audio Classes dive very deep into audio playback. Most people recognize the USB Audio Classes by support for different sample rates and the need for device drivers on certain operating systems. USB Audio Class 1 supports up to 24/96 using native device drivers from most operating systems like OS X, Windows, and Linux. USB Audio Class 2 supports up to and over 192 kHz using native device drivers from operating systems like OS X 10.6.4+, and some versions Linux.
The DragonFly's Class 1 USB Audio limitation is good for the most part. Supporting up to 24/96 audio is more than enough for most people. Even better is the fact that the DF can be connected to most relevant operating systems and work immediately with no software installation. Lack of Class 2 USB Audio support isn't the best for people who demand 176.4 and 192 playback but fortunately most applications will simply downsample the audio to a DF supported rate. When downsampling I really like the JRiver Media Center feature that allows users to select the exact incoming sample rate and outgoing sample rate. For example, it's possible to specify all 24 bit / 176.4 kHz tracks be down sampled to 24 / 88.2 for playback through the DragonFly (image ). Call me old-school but I still prefer downsampling to exactly half of the original rate rather than switching to a new sample rate family such as going from 176.4 to 96 kHz. The math is easier behind the scenes and the sound is better in my experience.
Learning To Fly
During the review period I listened through the DragonFly using both headphones and my main audio system. The two pairs of headphones I used couldn't be more different from each other on all levels. The Ultimate Ears ue11 Pro in ear monitors are tiny and very low impedance ranging from 4 - 50 ohms. The other headphones are the Sennheiser HD600 large open back, over the ear, with a nominal impedance of 300 ohms. The DragonFly was designed to work well with a wide array of headphones and I was determined to put it to the test.
I started with my Sennheiser HD600s and my 15" MacBook Pro Retina running OS X 10.8.2 with Audirvana Plus 188.8.131.52. I clicked through many of my usual tunes such as Leonard Cohen's Going Home, Ottmar Liebert's Not One, Not Two, and Randi Tytingvaag's Red or Dead. Leonard Cohen's deep rich vocal on Going Home sounded terrific with tons of texture and dimensionality as if he was creepily whispering in my ears. The lowest reaches of his voice were very clear, tight and possibly tipped up just a touch. Moving to Ottmar's Not One, Not Two acoustic guitar masterpiece made it evident the DragonFly was great but not the final answer in DAC performance. For the most part Ottmar's acoustic guitar sounded great. The DragonFly's deficiency was evident more so between the notes where space and air should carry the reverb tails away. There was no effortless and natural decay like the $15.5k DAC2X. To this I say so what. There is no free lunch and we can't have it all for $250. Anyone expecting DAC2X performance for DragonFly prices is crazy. Randi Tytingvaag's Red or Dead provided a great opportunity for the DF to shine on female vocals. Not surprisingly the DragonFly reproduced this track and the rest of the album wonderfully. With Audirvana's volume set to -7 dB I had all the volume I needed to reproduce Randi's voice in all its tack sharp detail. The DF also drove the deep and tight bass lines throughout the track very well. I'm a fan of resolution, hence my use of Spectral Electronics, and I could have used a bit more on this album. However, this is far from a showstopper and far from a major strike against the DragonFly.
Moving from my HD600s to Ultimate Ears ue11 Pro custom earphones I was immediately wowed by a blast of bass. I know the ue11s are very bass heavy but never had all the low frequency stars aligned as they did with this combination. My perceived slight increase in bass by the DragonFly along with bass heavy earphones and a tune full of rich bass such as Leonard Cohen's Going Home was a tad too much for my neutral taste. Maybe I should get into sales and market this combination to all the bass-heads thumping at stoplights annoying other drivers in a two block radius. Only joking, I was one of those kids way back in the day. I still have a great car audio system and must admit it can be a lot of fun when used appropriately. I don't want to give the impression that the bass produced by the DragonFly and my ue11 Pro earphones was mainly caused by the DF. The ue11 Pros are bass heavy to begin with and a good headphone amp will simply amplify what's already present in the earphone. This was evident in 90% of the music I listened to with this DF / UE combination. Seal's most underrated track Killer sounded great in both the album and acoustic versions. The same can be said of Glen Hansard's complete Rhythm and Repose album at 24 bit / 96 kHz. The emotion in Glen's lyrics and texture in his voice came through very well. I was pleasantly surprised how well the DragonFly handled the ue11 Pro earphones. It had plenty of juice to drive the low impedance in ear monitors. I had a very different experience using these earphones with the Wavelength Audio Proton (also designed by Gordon Rankin) and don't recommend that combination for serious or casual listening. Depending on one's musical taste the ue11 Pro or similar custom earphones may be a perfect fit for the DragonFly. There was no technical issue with this combination rather a personal distaste for a small portion of the sound on a small portion of my music collection.
Near the end of the review I connected the DragonFly to my main Spectral / TAD / MIT audio system. I figured the target audience for the tiny DragonFly is mobile or laptop users in need of something better, not audiophiles seeking a main system upgrade. I honestly didn't expect too much and thought this configuration was more to check the box that said I at least tried and listened for glaring issues that may be evident. To my surprise the DragonFly really shined in my main system. It sounded better than either of the aforementioned headphone combinations by a long shot. The quality that really stood out was the DragonFly's ability to reproduce reverb tails and decay much better than it had done with my headphones. Granted the DF is nowhere near the EMM Labs DAC2X in this category, but the improvement I heard with the DF at unity gain sending analog audio through a very revealing system was remarkable. This type of improvement should have audiophiles burning through bandwidth on Internet forums rather than arguing over who's Dad is stronger and has better ears to pass a blind listening test.
The $250 DragonFly sounded great on the vast majority of my albums. Keb Mo's track Every Morning, with its simple vocal and guitar, was terrific through the DF on my main system. I also enjoyed Suzanne Vega's Headshots much more through this combination as the signature heavy bass line throughout was nice and tight. Delineation between the individual bass notes and the drums was better with the DF my main system and overall very good through the DragonFly. Two areas where the DF had difficulty were heard on Nat King Cole's The Very Thought of You at 16/44.1 and Reference Recordings' Crown Imperial at 24/96. On the Nat track the DragonFly lost a touch of gloss present in his vocal. The best DACs I have heard reproduce Nat's voice in a lifelike fashion and this gloss is very evident. Not so with the $250 DragonFly. On Crown Imperial the track Niagara Falls can put any component through a torture test with its delicate highs, demanding lows, and wide dynamic range. The DF struggled a bit to reproduce the large wind symphony at times. The individual instruments combined into a melting pot when they should have been in a salad bowl. The sound from the DragonFly was jumbled and the fine details were lost during the complex passages. In the big picture this is a small issue that doesn't really matter for many users. Potential DragonFly customers should think about the music they like and the music that makes up their libraries when considering any product. I'm willing to bet the DragonFly will be exposed to far more and Oasis, Sia, and Coldplay than orchestras, symphonies, and choirs.
The AudioQuest DragonFly is certainly the coolest product I've used in recent memory. An asynchronous USB DAC running Streamlength code with a built-in headphone amplifier and analog volume control that is smaller than many USB flash drives. Increasing its coolness factor is the multi-colored LED illuminated dragonfly that indicates the incoming sample rate. Not only is that cool for audiophile geeks it's also cool for the masses trying to show some audio bling with their Beats headphones. In addition to being cool the DragonFly sounds great. The DF flew reproducing the vast majority of music in my collection while only faltering in a few circumstances. Above all the coolness and sound quality is the high value of a great component that retails for $250. I know of no other product that performs this well for so little money. The DF is in the running for Computer Audiophile Product of the Year and is running unopposed for the highest value product ever reviewed on these pages. AudioQuest has successfully targeted both mass and class with the DragonFly asynchronous USB DAC.
- Product - AudioQuest DragonFly USB DAC / Headphone Amplifier
- Price - $250
- Product Page - Link
- Product Manual - Link (4.7MB PDF)
- Source: 15" MacBook Pro w/ Retina Display, C.A.P.S. v2.0 Server
- DAC: EMM Labs DAC2X
- Preamp: Spectral Audio DMC-30SS Series 2
- Amplifier: Spectral Audio DMA-260
- Loudspeakers: TAD Labs CR1 Compact Reference
- Remote Control Software: JRemote, Apple Remote
- Remote Control Hardware: iPhone 4, iPad (3rd Generation)
- Playback Software Windows 7: J River Media Center 18
- Playback Software Mac OS X 10.8.2 : Audirvana Plus
- Cables: MIT Matrix HD 60 Bi-Wire Loudspeaker Cable, MIT Oracle Matrix 50 Analog Interconnects (RCA), AudioQuest Yosemite (3.5mm to RCA), 1.5 meter Mogami W3173 Heavy Duty AES 110, ALO Audio AC6 Power Cables, Wire World Silver Starlight USB Cable, AudioQuest Diamond USB Cable
- Network: Cisco SG200-26 Switch, Baaske MI-1005 Ethernet Isolator, Micro Connectors Augmented Cat6A Ethernet Cable, Apple AirPort Extreme, Cisco RVS4000 Router, Cisco DPC3000 Docsis 3.0 cable modem, Comcast Extreme 105 Mbps Internet Service