Sonnet Audio Morpheus DAC with Hermes Digital Bridge - Review

Those who have followed the evolution of high performance digital audio in recent years may know Cees Ruijtenberg, who was responsible for the excellent sounding DAC’s from Metrum Acoustics. I was previously highly impressed by Metrum products. Ruijtenberg is now responsible for the designs at Sonnet Digital Audio, and the Morpheus DAC, under review here, is what one would call the evolution of his previous designs. 

What is that approach? It is a R2R non-oversampling design. The Morpheus uses four proprietary SDA-2 ladder DAC modules, a deuce per channel. Everything works  together by custom written code running on an FPGA. Each SDA-2 module contains four resistor ladders, all told, a total of sixteen, which doubles the amount used by previous Metrum products.  The design and build of the Morpheus are very appealing, and the back panel connectors look to be of high quality. 

The Morpheus also includes a very well made metal remote, and volume control via variable voltage directly from the DAC chips. No digital attenuation! This method insures bit perfect volume adjustments, with output directly to a power amplifier, and no need for a preamplifier. Of course, this sonically purer path would preclude any other source components. The fully balanced DAC has both XLR and RCA analog outputs.  The Morpheus retails for $3399.

There are several digital inputs, including optical, coaxial, AES/EBU, and most interestingly, a choice of either USB or I2S. The I2S is via an RJ45 jack, instead of the more common HDMI connection. Our sample unit indeed did come with the I2S input instead of USB. The I2S option makes much more sense if using the Sonnet Morpheus Digital Bridge, a ROON compatible streamer, which we also received with the Morpheus.  Of note, the only limitation of an R2R DAC design is there is no DSD decoding. 

The Hermes, priced at $1200, is about two thirds the size of the Morpheus, and shares the latter’s high class build and appearance. It offers optical, coaxial, and the aforementioned 12S output. If purchasing the Hermes streamer with the Morpheus DAC, ordering the I2S option on the Morpheus makes the most sense. The Hermes is most interesting in that it allows adept users to swap out operating systems via a removable SD Card. An Ethernet jack connects to your network, and then all that is left to do is connect the DAC, and then enable the Hermes on ROON as an endpoint.

Set Up & Listening:

I set up the Sonnet pair in a system consisting of a Schiit Freya + preamp, an Audio Research VS55 power amp, and Spendor S3/5R monitors. Rob Fritz of Audio Art Cable, the US importer for Sonnet, was kind enough to send his rhodium plated power1 e Cryo power cords, and a 1 Meter length of his Audio Art Cable AAC IC-3 e2 Cryo Interconnects,

power cords, and a 1 Meter length of his Audio Art Cable AAC IC-3 SE2 Interconnects.  

I have ROON running on an M1 Mac Mini, and a large amount of CD rips and Hi-Res digital downloads on G-Tech hard drives. After plugging everything in, the only thing left to do was pick up my iPad Air and select music. We first ran through all of the Beatles remixes, beautifully done by Gilles Martin, the son of the late, great George Martin. First up was the 50th Anniversary Deluxe Edition of “Let It Be”, with the original album remixed at 96 Khz from the original multi track tapes, and scores of alternate takes, unreleased songs, and the original Glyn Johns 1969 mixes. All told, a thrilling package.

The Sonnet pair immediately let me know they were sonically top shelf. All of the nuances that Gilles Martin brought to these new mixes, and his superb balancing act of keeping true to the originals yet improving the fidelity, came through. It was a joy to hear the title track, along with “The Two Of Us”, “Dig A Pony”, and “I Me Mine” with such precision, and provided further proof of just how good the Beatles were as a band.

I went on to have the same experiences with the Sgt. Pepper’s, White Album, and Abbey Road remixes and outtakes. The acoustic guitars, drums, bass, and of course the vocals were rendered with so much clarity via the Sonnet combo, I just kept hitting repeat. If I had to use one phrase to describe the sound of these new mixes via the Sonnet gear, I would say “seductive”, which is where my preferences lie. No glare, no overly sharp outlines, and no fatigue. 

I did also listen to quite a few new recordings as well. The new release by the great Richard Ashcroft, former leader of The Verve, Acoustic Anthems Hymns, Vol. 1, in 24 bit, 48 Khz resolution, was a sonic spectacular via the Sonnet stack. These reinterpretations of Ashcroft’s songs that appeared on both his solo albums and his work with The Verve are less adorned, with more of a “live” feel. None of these versions top the originals in my estimation, but they were fun to listen to, and the Morpheus let me hear Ashcroft’s close miked voice and the overall energy of the performances.

An album I purchased from Bandcamp, and available in 24/48 resolution, Irish singer / songwriter David Keenan’s What Then?, literally gave me goosebumps courtesy of the Morpheus duo. Keenan’s voice is a thing of wonder, with fire, passion, and abstract lyrics wrapped in an alternative folk rock package, with modern flourishes. Fans of Damien Rice, Glen Hansard, or even Warren Zevon will be entranced. The arrangements are smart, and the smoldering performances make it impossible not to pay close attention.  This album really crystallized the strengths of the Sonnet designs. Classic, yet thoroughly modern.

For a recording featuring all acoustic instruments, also purchased from Bandcamp, I cued up Meridian Metaphor, by Icelandic bassist, band leader, and composer, Sigmar Matthiasson. This beautiful avant-garde instrumental album features a sympathetic group of players and off the beaten path instruments such as clarinet, out, tamboura, and a few instruments native to Iceland.  The basic language is jazz, but there are hints of folk and exotica. The recording is spacious, and streamed through the Sonnet stack, the small ensemble was positively cinematic in scale, yet beautifully intimate during more introspective passages.  

Circling back to classic rock, just towards the tail end of the review, I purchased a slew of newly released Pink Floyd remasters in 24/192 resolution. These albums have mostly been available digitally in CD quality only,  with some exceptions, so this was an unexpected treat. The Morpheus presented these classic albums with such poise, and there was a wide screen, analog like flow that was irresistible. The earlier albums, such as The Piper At The Gates Of Dawn, A Saucerful of Secrets, and Meddle, really benefited from the high resolution mastering.  But later albums like The Wall and The Final Cut also were revelatory in 24 bit. 

Ergonomically, the Morpheus and Hermes were plug and play all the way. No deep dive into the manual, no need to be a networking wizz. They just worked. Nitpicks? Well just one...I would like to see a sample rate / bit depth display on the front panel of the Morpheus. Other than that, a really nicely presented component. 

Audio Art Cables:

A note about the Audio Art Cables supplied by Rob Fritz, the US importer for Sonnet. Using Audio Art power cables on the Hermes and Morpheus produced an immediate jump in performance, a lower perceived noise floor, and an overall sense of ease. These are clearly superb products, they are beautifully made, and are flexible enough to situate in any system. The Audio Art interconnect was also the perfect match tonally for the Sonnet products. Neutral, tonally rich, and open sounding. The Morpheus and Hermes pair were a great fit with my system’s overall presentation, and with the Audio Art cabling added in, everything just fell into place sonically. I can’t recommend the Audio Art products more highly.

Conclusion:

The Sonnet digital duo, the Morpheus DAC and the Hermes streamer are what I would call the perfect products for those seeking accurate, natural, and musically pleasing sound. I would go as far as to say this would apply even more so to “digital holdouts”, those who have not invested in high end digital components, or have preconceived notions about digital audio performance. The Sonnet designs deliver the goods, and would convert even the most stubborn digital skeptics. 

Sonnet also makes a pair of mono block amplifiers called the Kratos. All products are made in the Netherlands, Rob Fritz of Audio Art Cable is very accessible, and potential customers are encouraged to contact him with any questions, for an audition, or to discuss system matching. My time spent listening to the Sonnet Morpheus DAC and Hermes streamer were well spent.

Specifications:

Sonnet Morpheus MK-II

Balanced  Non oversampling DAC

Two SDA-2 dac modules per channel in differential mode

Input 1x optical, 1x coaxial and 1x  AES/EBU and USB

Output 1x stereo pair single ended  2 Volts RMS. In -10dB mode 0.66 Volts RMS

Output 1x stereo pair XLR balanced 4 Volts RMS In -10dB mode 1.33 Volts RMS

Sampling rate Optical 44.1 – 96 kHz

Sampling rate Coax and AES/EBU: 44.1 -192 kHz

Sampling rate USB 44.1 – 384kHz

Aluminum six button remote control included.

Sonnet Hermes:

Inputs: Lan (local area network) max. 100 Mbps

Outputs: 1x optical Toslink, 1x RCA coax, 1x AES/EBU and I2S.

Sampling frequency:

Optical : 44.1 – 96 kHz sampling.

Coaxial: 44.1 – 192 kHz sampling.

I2S: 44.1- 192 kHz sampling.