Another Spare Parts Review: The Apogee Duet 2
Can't you feel the rock dust in your lungs?
Strictly speaking, this spare parts review of the Apogee Duet 2 required that I purchase a few small items. The Duet 2 is really intended for professional recording and monitoring, so I had to get a few adapters to make it work with audiophile electronics. Specifically, I bought the Duet 2 breakout box, which comes with a two-meter umbilical cord and allows XLR connections for balanced output as well as ¼" inputs for instruments or line-level signals like a phono preamp. I also bought some Cardas adapters allowing the female XLR line-level outputs to convert to female RCA's. I also bought the Cardas mono ¼" to female RCA to allow line-level inputs, albeit single-ended only, in case someday I want to use the Duet 2 as an ADC to rip vinyl. Although for the purposes of this commentary, my main point was to test the Duet 2 as a standalone DAC. My main arrangement consisted of the following:
(1) 17" MacBook Pro with 3.06 GHz Intel Core 2 Duo processor, 8GB of RAM and a 256GB solid state drive, running Mountain Lion, Pure Music and iTunes
(2) One-meter Locus Design Axis USB cable
(3) Apogee Duet 2 with two-meter umbilical cord and Apogee breakout box
(4) ½ meter Kimber Hero balanced interconnects/4.5 meter Cardas 2X24Ms
(5) Blossom Blo-0299 balanced headphone amp with Welborne Labs power supply
(6) Moon Audio Black Dragon balanced Denon AH-D5000 headphones
It took a while to get things set up and running. I had download the latest version of Maestro 2, the control program for the Duet 2, and reset Pure Music to defaults to eliminate the DSD setup I had created to review the Mytek DAC. Then I had to reregister the Duet 2 and reconfigure Pure Music for 0dB output (as opposed to "+" or "-") as well as reset Memory Play. Compared to the Apogee's built in headphone amp, which sounds a little bit bright, this arrangement—though consisting of many more wires—sounded substantially more neutral. The 24/96 download of The Chieftains' Voice of Ages (from HDtracks.com) sounded particularly dynamic and clear without seeming excessively forward.
Once I got everything configured and running, I decided that I needed to do some serious listening. So my first choice was the 16/44.1 CD import of Marilyn Mazur's Elixiron the ECM label, using Apple Lossless Compression and with error correction activated. I can say, overall, the sound seemed excellent with good imaging and soundstaging and profound dynamics with plenty of extended deep bass. My only complaint lay in a slightly metallic sound to the treble; but that could be in the recording. So as a point of comparison, I queued up the 24/192 download of Bill Evans' Waltz for Debby (again from HDtracks.com). It only took a few tracks to confirm that deep bass, overall dynamics, and depth remained superb; and, while the treble sounded substantially less metallic, it did not have the sweetness or sparkle that I remember from the Woo WA7. Perhaps that's okay. After all, the Duet 2s designers had professional recording and monitoring in mind, not recreational listening. So it makes sense that they would give it a different sonic signature, one where clarity and detail trumped finesse. Having said that, I am evaluating its performance as an audiophile-grade DAC; so I decided that—painful though it may be—I should try inserting some softer sounding cables into the mix, specifically my 4.5 meter Cardas 2x24Ms. They makes for a mess on the dining room table but should help to take the edge off of the sound. Going back to Elixir, the treble has lost its metallic edge and there's greater overall warmth and air or ambience. It's much easier to listen to the music and bask in the sound rather than feeling like something negative has been added. Technically the cables have "2x23.5M" printed on them; but I remember ordering 2x24M for use as microphone cables (although I have never done any actual recording with them). I also forgot to mention that I had to reset the "DIM" setting in Pure Music to minimize digital overs, a rather nasty form of distortion.
Switching to the 24/192 download of Bach Trio Sonatas by Florilegium from Channel Classics (the PCM version, not the DSD version, because the Duet 2 can't process DSD files), I notice a slightly brighter presentation and, again, sort of wish I had that Woo WA7 in the chain; having said that, there's nothing wrong with the sound of the Duet 2 going through its many meters of cables and the breakout box to my Blossom Blo-0299. Also, although I am using the Welborne Labs power supply for the Blossom, which does enhance the sound, everything is plugged into an ordinary hardware store power strip, not into one of my Equi=Techs or my Power Plant 10s. I am using a thick, well shielded, but quite generic power cord for the Welborne Labs power supply and the cable that came with the MacBook Pro for the computer. Although the Duet 2 can be powered with an accessory wallwart, I am running it off bus power supplied by the MacBook Pro via the Locus Design Axis USB cable, mostly because it simplifies things. The next step involved plugging the Duet 2 into the hardware store power strip via its walwart power supply. Returning to Bach Trio Sonatas by Florilegium, I have to confess that—much to my great surprise—the sound seemed substantially more open with better delineation of detail, a gentler treble, and deeper bass definition. So the convenience of the bus power was outweighed by the better sound quality of the wallwart. For the first time, I really felt that this mostly spare parts arrangement competed favorably with the Woo WA7. Before I press any further, I should mention I contacted Cardas about that printing on the 2X24M; and they responded with this comment:
The 2x24M has had several printings over the years. It uses 23.5 AWG conductors and has been nick named "2x24M". You have the current product, it seems we need to update the print wheel...
Seems reasonable to me. Getting back to the sound of the Duet 2 with the wallwart, I listened to Karrin Allyson's ‘Round Midnight in its 24/48 download form from HDtracks.com, and while it sounded better, there remained a slight metallic edge to the treble that I just couldn't remove from the Duet 2 no matter how hard I tried; for $595.00 for an ADC/DAC with fully balanced connectors and built in microphone preamps, I guess I shouldn't complain; however, I really like Apogee and I just wanted it to sound better than it did. So it goes. As one last experiment, I used Cardas adapters that I had to terminate the 2X24M cable with male RCA connectors, and then plugged the whole thing into my Tri TRV-84HD headphone amp—unlike the Blossom, which uses all solid-state electronics—uses only tubes. After letting the Tri warm up a bit, I replayed the Karrin Allyson download and I will say that the filtering effect of the tubes softened the sound of the treble enough that music emerged as more enjoyable; however, you could still tell that treble sounded a little colluded or harsh. So I guess I would say that if you plan to make professional recordings, the Apogee—particularly with its breakout box at $99.95 extra—is a great buy; but I really couldn't recommend it as a standalone DAC. Of course, everything that sounds substantially better will likely cost a lot more; so if you have a Macintosh and can't afford an Ayre QA-9 and QB-9, not to mention a good pair of microphone preamps, the Duet 2 may just be your ticket; however, if you want really good sound for office listening, I would recommend saving your pennies for something like the Woo WA7.
P. S. I should mention that—before I started this commentary—I was using my Apogee Duet 2 with a 15" MacBook Pro with the Retina display, the Locus Design Axis USB cable and a pair of Moon Audio Blue Dragon Sennheiser HD650's. The Blue Dragon 650's have such a soft sound that they compensate for the brightness of the Duet 2 and I never had any complaints about the sound. It was only after I reviewed the Woo WA7 that I realized I could get better sound for not a whole lot more money assuming I also use a more resolute pair of headphones, such as the Audez'e LCD-2's with the Moon Audio Silver Dragon cabling. More food for thought, for sure...