Resonessence Labs CONCERO

Following the success of their statement INVICTA DAC(CA$3,999) Resonessence Labs have fired their first salvo into budget territory.  They’ve come armed with two-for-one ammunition:  a USB-S/PDIF convertor and DAC packed into a single unit (CA$599).  You can purchase direct from Resonessence themselves or via their dealer network.  An additional $50 bundles Apple remote (for playback control and filter selection) and USB power supply (required for S/PDIF DAC mode) into the bargain.  Accessories aside, the whole shebang is manufactured and assembled right there in Canada.

Custom coding

On paper, basic expectations are comprehensively met: separate clocks for 44.1 kHz and 48 kHz sample rate families and an in-house coded asynchronous USB solution.  Concerned that it will introduce jitter, Resonessence Labs have dispensed with PLL circuitry.  No, it’s not another XMOS implementation.

A DAC’s sound isn’t uniformly influenced by the decoding silicon – there’s I/V conversion and output stage to consider – but its sticker price certainly is.  The CONCERO is the digital guts of the INVICTA wedded to a cheaper ESS Sabre chip – the 9023.  Remember: the INVICTA runs a pair of Reference ESS Sabre 9018 and sells for CA$3999.

Resonessence combines their own custom (FGPA) code and the Cypress CY7C68013 chip in a USB receiver that uses their own asynchronous code and handles remote functions.  Their designer Mark Mallinson emphasizes that “they spent a lot of time making sure that the speed differences between the computer’s clock and the high quality/low phase noise reference of their DAC’s don’t cause issues – the code is written to handle when the computer is both faster and slower than the source. This required a custom solution.”

Remote control, up-sampling and filters

Team Resonessence have pulled some neat tricks with the CONCERO’s functionality.  Hi-jacking an Apple remote control is a clever trick.

The up/down buttons toggle on/off states for digital and analogue outputs; useful if you’re keen to minimize internal processing but I could discern no audible benefit when doing so.  Play/pause and fwd/next sends the same signal back down the USB cable to your host computer; a real boon if your existing PC or Mac has no existing remote control receiver.  Windows users will require the USB Class 2.0 driver (downloadable from the Resonessence Labs website).  Windows 8 compliance is now in the bag.

Unlike the price- and function-matched rival UD384 from Taiwan’s KingRex, no external power brick is required for the CONCERO to get going.  It runs on 5V USB fuel.  Engineering smarts have been deployed here too: connect the CONCERO (via USB cable) to a host computer to enable USB DAC mode OR plug the same USB cable into a power-only ‘phone charging’ brick (supplied in the power pack) for S/PDIF DAC mode.


Julian Cope’s epic and sprawling Peggy Suicide is presented as full, smooth and rich.  It’s a sound that’s free from digital glare and metallic sheen.  Not as obviously detailed or airy as the Micromega MyDAC , the CONCERO is much more conducive to longer listening sessions.  Build quality on the Resonessence Labs unit underscores the toy-like appearance of the Micromega.

There’s more.  Pressing the menu button on the Apple remote cycles through three filters: native mode (logo blue), IIR filter (logo magenta), apodizing filter (logo magenta).  The latter two 4x up-sampling filters work their magic only when fed 44.1 and 48 sample rate material.  I preferred the IIR filter.  It demonstrated greater heft with lower frequencies and was more rhythmically self-assured than both native mode and the apodizing filter.  The latter revealed more air in recordings but strayed into brightness on occasion.

Whichever filter is preferred for one style of music might not be suited to another.  Spinning (an ALAC rip of) the original CD of Thomas Dolby’s Golden Age Of Wireless, the IIR filter tamed some of the needling transients and added a little body and drive.  On the other hand, the lighter, crisper native mode filter dials back some of the bass on already-beefy techno: Sigha’s Living With Ghosts or Surgeon’s Fabric mix being two such examples.  The take away here is that the user can tweak the sound to balance out their existing system’s sonic characteristics.

Higher sample-rated source material – or digital music already software up-sampled  to 88.2kHz, 96 kHz, 176.4 kHz and 192 kHz – is passed bit-perfectly down the chain; the filters remain dormant and the logo holds fast to blue.

The gift that keeps on giving

There aren’t too many combo currently units doing the rounds.  One could applaud Resonessence Labs for packing filtering flexibility into a six hundred dollar DAC and then go home.  But no.  There’s USB bridge mode too.

As a USB-S/PDIF convertor, the CONCERO is utterly superb.  The jitter-reducing sauce that got poured into the recipe brings greater fluidity to Peachtree’s Nova125.

In this reviewer’s broad experience with USB convertors, the CONCERO is the next device to join the Audiophilleo and John Kenny’s battery-infused modified Hiface as the goto models at their price point. If you find the Audiophilleo too dry or the JKSPDIF too smooth, a happy medium might be found with the Resonessence box: glabrous with excellent tonal saturation.  There’s less transient bite than the Audiophilleo.  Think black coffee laced with a few drops of cream.  Yum.

The same up-sampling filters are available in USB bridge mode but with some volume drop-away in all but native (blue light) mode, a necessity to avoid filter distortion on the digital output.

Note: both filter and native modes are level matched at 1.2V on the analogue outputs.  The Concero is quieter than rival units and possibly isn’t for ideal for those lacking headroom in their amplification chain.  Conversely, a cooler analogue output is suited those with too much headroom or those with more sensitive inputs on vintage amplifiers and receivers.

In a recent experiment to extract audio from an iPad with Camera Connection Kit and iFi’s iUSBPower, the CONCERO and iFi’s own iDAC were the only DACs to meet the challenge without issue.  A USB clocker and DAC for the iPad.  No other unit currently offers this one-two at any price.

A keeper

I could easily live with the Concero as a long-term decoder; its eloquence and articulation of musical spirit is simply terrific.  Selectable filters lift its flexibility when applied to different music genres (and listener mood) whilst the USB bridge operation is up there with the best of them at this price point.

For those wondering: yes, the Concero is a superior-sounding unit to the Schiit Modi.  It offers more refinement and tonal depth.  Modi aside, I can think of no greater bang-for-buck currently available in the budget digital space.  Hands down a triumph of innovation and sonic flair, Resonessence Labs’ CONCERO exceeds expectations by a healthy margin and then some.

Resonessence Labs CONCERO