Resonessence Labs Concero HD Digital to Analog Converter

Device Type: Digital to Analog Converter
Input: 1x Coax S/PDIF, 1x Asynchronous USB 2.0
Output: 1 pair RCA
Dimensions (H x W x D): 7/8" x 4" x 4" (approximate)
Availability: Direct and through Authorized Dealers
Price: $850.00CAD, Concero HD Bundle which includes an Apple Remote and Apple USB power module and cable $900.00CA

Way back when I reviewed the Resonessence Labs Concero (see review), I wondered/wished, "I wonder if they could easily add DSD capabilities to the Concero?" Depending on your definition of "easy", the answer is a resounding yes. It did take a new DAC chip but ESS came to the rescue and the little Concero now has two siblings; the HD with its DXD/DSD capabilities and the HP which adds a headphone amp to the HD. Like the original Concero, the HD in addition to functioning as a Coax S/PDIF and USB DXD/DSD DAC, it can also operate as a USB to S/PDIF converter handling up to 64x DSD since 128x DSD is beyond the S/PDIF specifications according to Resonessence Labs.

The Concero HD uses the latest 32bit ES9018-2M Sabre DAC from ESS and the USB receiver chip is from Cypress Semiconductor. The HD has retained the two custom Resonessence Labs filter choices found in the original Concero. These include an IIR up-sampling filter and an Apodizing up-sampling filter selectable with an Apple remote which is included in the Concero HD Bundle from Resonessence Labs or available direct from Apple for $19. The Concero HD's front facing backlit logo lights up blue for no filter and magenta for both upsampling filters. Around back are the Concero HD's inputs and output and include a USB Type B input, a Coax S/PDIF input or output, and a pair of single-ended RCAs for the output. The HD is powered from the USB bus or if you prefer you can use a USB power module to power the HD when in S/PDIF DAC mode. When the HD senses a power-only USB input, it automatically switches to S/PDIF DAC mode. You can also set the operating mode with the Apple remote.

DSD capability is provided using the DoP (DSD over PCM) protocol and Mac users can take full advantage of this as well as DXD playback out of the box whereas PC users need to install the Resonessence-provided drivers to get the same functionality. Since I used my MacBook Pro, I was ready to go and connected the Concero HD with the AudioQuest Diamond USB cable and a pair of Auditorium 23 single ended interconnects supplied the analog signal to my Leben CS-300XS and Pass INT-30A and both integrated amps handed off to my DeVore Fidelity The Nines.

The Sound of HD
If you read my review of the Resonessence Concero, you'll recall that I preferred the first up-sampling filter, the IIR filter, and that preference remains true for the HD version as well. It strikes me as hitting a happy medium between the flatter and more etched sound of no filter and the slightly more garish Apodising filter. So for pretty much the majority of this review, the Concero HD remained magenta when playing back CD-quality and 48kHz recordings and blue when playing back higher sample rates and DSD since the filter is bypassed in these cases. While we're talking about preferences, I preferred the Concero HD when paired with my Leben CS-300XS as it sounded richer and fuller as compared to the Pass partnering. This is the exact opposite of my findings with the recently reviewed NAD D 1050 (see review) as its inherent fatness sounded best to my ears when paired with the Pass.

The Concero HD also retains a lot of the character I described in the original version. The HD is resolute, clean, crisp, and articulate. Recordings sound free from anything other than the bits of the recording with no excess piggybacking apparent on any frequencies. This recipe also makes the HD sound fast and somewhat lean especially when compared to what struck me as a fat-sounding DAC like the NAD D 1050. Which leads to me to suggest proper pairing for the Concero with systems that do not already lean toward the lean.

I have a playlist setup in Audirvana consisting of all DSD and DXD recordings. This makes it very easy to sit back and see how a given DAC handles single and double rate DSD as well as DXD. Kind of like a HD greatest hits. And what's become no surprise around these parts, I thought DSD sounded plain lovely. Whether the source was ripped from vinyl, transposed from DXD, mastered from analog tape, or native DSD all the way through, the Concero HD delivered that DSD naturalness in all of its wonder. I also listened to the entirety of Rachel Podger's wonderful performance of Vivaldi's Violin Concertos from Channel Classics in DSD and it was thrilling. Nat "King" Cole's Just One Of Those Things from the just-released DSD download from Acoustic Sounds was in-the-room eerily lovely.

The Concero HD retained its firm grip even with DSD and it proved to be more resolute than the similarly priced Teac UD-501 (see review). The Teac delivers a softer and more billowy sound and here I'd say that one's preference rules the day in terms of which is "better". I would generalize by saying if you feel your system is leaning toward the lean and light weight already, the Teac may be your best bet for an ~ $800 DSD-capable DAC. If on the other hand you have plenty of body already and want a DAC that can sort out complex music and deliver gobs of resolution, the Concero HD was made for you. With DXD, I initially found that the Concero HD could get a tad hard and flat sounding in the upper registers but with the recent firmware upgrade (2.3.0), this issue appeared to be resolved.

I also ran the Concero HD in USB to S/PDIF mode with the Mytek Stereo192-DSD DAC taking the HD's coax S/PDIF output in my desktop system. As with the original Concero, the HD also lent its sound to the Mytek delivering a tight and resolute sound picture with superb control. In terms of an A/B comparison to the Mytek running solo using the its Firewire input from my iMac, the Mytek offered up a slightly more robust sense of body and a bigger overall sound as compared to using the Concero HD as USB to S/PDIF converter. I'd say the HD offers a resolute and detail-focused sound although the differences in presentation here are fairly subtle.

It's All in the Details
As with the original Concero, there's a lot to like about the Concero HD. While I felt it walks a fine line between just enough and too much resolution, and ancillary gear may send it one way or another, I nevertheless enjoyed my time with the HD. When properly paired, which for my tastes meant the Leben CS-300XS, I was served up a rich and resolute presentation that drew me into music's finer moments without losing site of the bigger picture. With the addition of DSD and DXD playback, Resonessence Labs has made a good thing better.

Associated Equipment

Also on hand and in use during the Concero HD review: NAD D 1050, Teac UD-501

torturegarden's picture

Thanks for the review. I will be in the market for a budget (~$1M) for a new DAC that can handle DSD once I end my temporary retirement. I'll add this one to my shortlist, along with the Teac. 

raytang's picture

Thanks for your review. You have compared using the Concero HD as USB to S/PDIF converter vs the Mytek Stereo192-DSD DAC. I'm very insterested to find out how the Concero HD using the single-ended RCA outputs comparing to the Mytek ?

Michael Lavorgna's picture

...the Mytek DAC is $1,695 or double the price of the Concero HD. The Mytek also offers a headphone amp, digital and analog volume control, multiple inputs and RCA and XLR outputs...So not exactly an apples to apples comparison.

In terms of performance, I'd give the Mytek the edge. It retains the Concero's resolution while adding more body and weight. It is to my ears a more engaging sounding DAC.

fastguitars's picture

just curious if the Mytek you compared the Concero against is a reveiw item or is it yours???? As, claiming that a product that cost nearly $1000 less then  your Dac is "better" or "equal", would be a tough call to make in public, im sure.

Michael Lavorgna's picture

...the Mytek is not mine. It is on loan so I have no skin in this game, so to speak.