A DAC is a DAC is a DAC. No, it’s not. It converts digital audio to analogue. That’s about the only thing DACs have in common. Some sound warm, some sound thin, others may add a metallic character to music and sound, but all are different. They are wildly different in form factor too. I have a small AudioEngine D1 on my desk here. I thought you couldn’t go much smaller but Audioquest just did. They managed to cram a complete DAC in a USB stick. The most amazing part of this is that it actually sounds good.
The DragonFly is based on a 24-bit ESS Sabre DAC chip. DragonFly accepts audio and music files ranging from MP3s and CD-standard 16-bit/44kHz to native 24-bit/96kHz high-resolution, regardless of music file format. The Audioquest representative sent me a Big Sur mini jack to RCA cable to test the DragonFly with.
Co-engineered by Gordon Rankin, the DragonFly uses Rankin’s Streamlength asynchronous USB protocol and incorporates a Burr-Brown headphone amp with a 64-step analogue volume control.
Rankin’s protocol is special in that it allows to handle jitter well. A USB DAC can operate in adaptive mode, which relies on the computer’s USB-bus clock, which usually is inefficient. It can also operate in asynchronous mode, which allows the DAC’s clock to command the timing of the digital audio transfer. Rankin, who pioneered the asynchronous mode for Wavelength Audio, is said to have designed the DragonFly circuitry for AudioQuest.
In addition, the DragonFly has two internal clocks optimised for two sets of sampling rates. It can thus handle four sampling rates in all, and its dragonfly-shaped LED glows in a different colour for each one. When the DragonFly glows magenta, you know it’s sampling at 96 kHz. Amber is for 88.2 kHz, blue for 48, green for 44.1, and red is for… standby.
The highest sampling rates the DragonFly can handle (176 kHz and 192 kHz) are not available for output. The Mac automatically downscales to 88.2 or 96 kHz. Finally, the DragonFly also has a built-in 64-position analogue volume control that follows the computer’s main volume control. The digital volume control in most music player applications will degrade the signal.
For my tests, I had both the player’s volume and the Mac’s set to maximum, managing the volume with the AudioEngine A5+ volume knob. For the tests with my Sennheiser HD650, I used the Mac’s volume settings, not the player’s. I tested the Audioquest DragonFly with AudioFile Engineering’s Fidelia with dithering turned off, and listening to a whole range of classical music ranging from Bach organ works to Elgar’s Pomp and Circumstance. I reran the tests with Audirvana Plus.
My experience with DACs consists of listening to two versions of the Music Fidelity DAC, and an Apogee Duet Firewire, while these days I play music through the AudioEngine D1 mostly. After letting the DragonFly and the Big Sur cable burn in for half a day, I started listening for real.
The first thing I noticed is that the DragonFly sounds closer to the latest Musical Fidelity DAC than to the AudioEngine D1. I got more clarity from the DragonFly than I got from either AudioEngine D1 or Duet. With respect to sound body and warmth, the DragonFly was on par with the Duet. The sound stage with the DragonFly is more open than the other two, but only by a margin.
Using Audirvana Plus, the music really opened up. Both the D1 and the DragonFly were identified as candidates for “Integer Mode”, a mode in Audirvana Plus that surpasses OS X’s internal sound tunings completely. Not surprisingly, this gave the best results.
It’s with this test that I was surprised with the difference in detail. There’s a dramatic difference between the D1, the Duet and the DragonFly when it comes to detail, with the DragonFly winning big time. It’s not as if the D1 (or the Duet) sounds muffled, but with the pair of Sennheisers over my head I could clearly hear a music stand almost fall over with the DragonFly whereas the same sound was harder to define with the D1.
In the highs, the DragonFly goes beyond the D1 and the Duet, which sound more like “velvet”. It is what makes the DragonFly a champion in clarity. Usually, an amplifier or DAC that goes well in the highs, lacks in bass. However, that is not the case with the DragonFly. Its bass performance baffled me. I listened to several organ works, among which one of Cesar Franck recorded on the organ of St. Eustache in Paris (Dorian Recordings 1990). This organ has an enormous dynamic range (down to 16Hz) and an incredibly broad tonal colour the recording engineers have painstakingly tried to save. The CD notes mention that in order to enjoy the full sound, playing equipment should be of the highest quality.
I was very curious to see whether the DragonFly would be capable in the bass area, enough to at least convey the lowest sounds without booming too much. It did. A USB stick sized DAC with a Sennheiser HD650 plugged in could reflect the deep rumbles of the organ…
As for the Big Sur cable, I was happily surprised by its quality, both of build and sound characteristics. My cables of choice so far have been the Supra EFF-IX, a Van Den Hul Hybrid and a QED Reference cable.
The Big Sur has a better quality of build than the Supra and the QED (e.g. braided outer jacket), but I found the sound to be about the same as with the QED. However, with these cables you always have to convert from RCA to mini jack, which you don’t have to do with the Audioquest Big Sur with its mini jack to RCA!