Resonessence Labs HERUS: an ultra-portable DSD DAC


Resonessence Labs this week officially launches its teeny-tiny HERUS DAC / headphone amplifier; its machined aluminium enclosure fits in the palm of your hand. However, the big news is that the HERUS decodes DXD/DSD and sells for CA$350, making it possibly the lowest cost PORTABLE native DSD decoder to date.

Outputting up to 2.4V from its quarter inch headphone socket the HERUS can drive headphone loads from 600 Ohms down to 32 Ohms. It’s fully compatible with Windows, OS X and Linux computers but, adding greater source flexibility to the mix, Resonessence Labs have confirmed that the HERUS works with the iPad + iOS 6 + CCK.  iOS 7 compatibility TBC.


Much like RL’s CONCERO range, the host OS’s software volume control sends digital markers to the onboard Sabre DAC chip for it to carry out the attenuation. Also trickled down from the CONCERO range is the Xilinx FPGA core processor that runs Resonessence Labs’ custom jitter-reduction code and filtering.


“The miniature device is USB powered and achieves better than 0.01% (80dB) THD and better the 105dB of SNR.”, says Mark Mallinson. The USB input is confirmed as being both UAC 2.0 compliant and asynchronous.

The HERUS begins shipping on the 1st October. Attendees of RMAF 2013 can check out the Herus DAC / headphone amplifier in the Resonessence Labs room.

Further information: Resonessence Labs | Addicted To Audio

Written by John H. Darko

John lives in the NOW + HERE = NOWHERE. He derives an income from the ad revenues of DAR. John is also an occasional staff writer for Stereophile, 6moons and TONEAudio.

Twitter: DarkoAudio
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  1. That seems like poor planning IMO. Who cares how small it is? Its an ‘audiophile’ piece. We want ‘real’ connectors, not mini crap. If it cost $25 ok, but $350? Sorry,.. next…

    • I understand this might to be the product for YOU but a lot of folk are interested in good sounding, portable DACs. This sub-market is expanding rapidly: the HRT microStreamer, AQ Dragonfly, Meridian Explorer, M2Tech Hiface DAC and (to come) Light Harmonic GEEK.

  2. …”runs Resonessence Labs’ custom jitter-reduction code and filtering”…

    Any idea what filter will it use?

  3. Wow this is perfect. I can replace my aged preamp, driving my 150 watt per channel power amp directly, gain a great headphone amp, get the concerto sound and pocket it for the cottage trips. I’ve already picked up the quarter inch to RCA interface cable. Imagine all this for $350! And dsd.

  4. My Herus arrived about a week ago, and I thought I’d give a few impressions.

    Firstly the only USB cable I had was a 1.8m printer cable. I had quite a few problems with this cable and the Herus. From intermittently not playing music at all or not playing certain sample rates and also problems with volume where one level would be complete silence and the next level was full volume. I ordered a male type-A to male type-B adapter (not a cable) off eBay and that fixed the issues I was having with the printer cable.

    I would say this DAC tends to be towards the energetic (or bright) balance, which I don’t particularly like (I prefer warm or neutral). I have heard that ESS Sabre DACs have this characteristic and this is the first time I have heard one.

    The sound quality is very high for a dongle. It is definitely a step up from the HRT microStreamer that I had. I liked the sound balance of the HRT more (it is more neutral) but it had a slight edge to the sound which I found fatiguing. The Herus doesn’t have any kind of edginess to the sound.

    I noticed an improvement in sound quality when upsampling from 44.1 to 176.4 whether using BitPerfect or Onkyo’s HF Player.

    I had a lot of trouble getting DSD playback to work. Unfortunately I had trialled Audirvana previously and not purchased it so I couldn’t trial it for DSD playback. JRiver didn’t work at all for the DSD files I had, just silence. Pure Music worked once on a DSD64 file that I had (it converts the DSD files to DoP ALAC files). I tried running the ALAC using BitPerfect but just silence. Pure Music is no longer playing DSD files for me now and I’m not sure why (it crashes).

    Onkyo’s HF Player on the iPhone 5 plays the DSD64 and DSD128 files fine (but not with my printer cable only the adapter).

    The main DSD files I have been playing around with are some of Far Cry’s samples they posted on their kickstarter page:

    Comparing the DSD128 with the 192/24 I would say that the DSD128 sounds slightly more metallic and lean and more delicate, whereas the 192/24 has more body and colour. I’m not sure whether these differences are in the way the material was recorded, the digital formats, or the electronics of how the Herus plays the different formats. I couldn’t quantitatively say the DSD was better, but different.

    The build quality of the Herus is very high. The HRT and it’s white USB cable look like a PC accessory, whereas the Herus looks and feels like a quality audio product. The HRT indicates the current sample rate with LEDs whereas the Herus doesn’t indicate at all the sample rate which can be a little frustrating.

    Would be interested to hear anyone else’s experiences with the Herus.