Digital Processor Reviews

Though it's named after the Roman god of sleep, I found nothing lethargic about the Morpheus. I'm happy to report that, like some other R-2R DACs I've heard, it takes music out from behind the glass wall of "digital sound" and renders it in a vivid, fleshed-out manner. R-2R DACs often get knocked for rolled-off frequency extremes and a sound that has a generalized way with detail, but this one managed to dig out copious detail from every recording I played and brought to the game a pristinely extended treble and authoritative bass—strengths associated with delta-sigma DACs. More than any digital source I've heard, the Morpheus unites two aspects of musical reproduction that are thought to belong to these rival design philosophies: it sounds extended, neutral, and resolute while excelling at capturing the music's presence, weight, and texture. I listened to the Morpheus with its volume control bypassed, as I preferred the results using my Shindo Aurieges preamplifier.

To get a sense of how the Morpheus resolved spatial information, I put on the title track from Frank Sinatra Sings for Only the Lonely (24/48 FLAC MQA stream, Capitol/Tidal): When Bill Miller came in with his slightly schmaltzy part, his piano sounded like it was located about 10' behind and slightly to the left of the left speaker, an effect that most DACs I've lived with can't muster. The Morpheus consistently projected a soundstage that was taller, wider, and deeper than the plane of the speakers and placed singers and instruments in that space in a solid and tangible way.

When I first listened to the Dutch DAC using its USB input, I was surprised at how similar the Morpheus sounded to my Denafrips Terminator (footnote 2), another hybrid R-2R DAC. The much larger Terminator, which costs about $1000 more than the Morpheus's retail price of $3399, boasts a more reassuring bass and springier dynamic contrasts (perhaps owing to its more robust power supplies and chassis), but these differences are slight, and otherwise there isn't much to separate their performance.

A more meaningful difference between the two DACs lies in how they present data from their respective digital inputs. With the Terminator, I find myself torn between the sound of its USB and I²S inputs. With the Morpheus, I found the USB input to be my least favorite way to listen. Music played through its AES3 input sounded more vivid, but things got really interesting when I swapped in the I²S module.

To use an I²S input, you need a companion device with an I²S output. So, Sonnet sent along its matching Hermes Digital Bridge, which also functions as a Roon endpoint.

Through the I²S input, instruments became less homogenized, each sounding more distinct and colorful, and everything in the soundfield grew more precise, solid, and well-organized. The improvement was easy to discern and not at all minor—imagine switching from a budget Pentax lens to a Leica Summicron. On track after track, I found myself surprised at having my attention drawn to musically significant details I hadn't appreciated before. Listening to "Lay Lady Lay" from Bob Dylan's Nashville Skyline (AIFF rip from Sony Records International SICP 30481), I was delighted by the absurd yet inspired decision to have drummer Kenny Buttrey play a cowbell and bongos on a country ballad; the sound of his drumstick on the cowbell sounded so eerily present that it made me grin. (A studio janitor who came into the drum booth to empty the ashtrays—and held the instruments while Buttrey played them—happened to be Kris Kristofferson.)

Hardly a month goes by when I don't listen at least once to J.S. Bach's Cantatas, BWV 82 and 199 (16/44.1 FLAC stream, Nonesuch/Qobuz) by the late, sorely missed mezzo-soprano Lorraine Hunt Leiberson. Her performance of "Ich Habe Genug" ("I Have Enough") builds toward a kind of rapture; no singer I've heard has embodied more deeply the meaning of the cantata's words. The Morpheus was able to reveal the warmth in Hunt Leiberson's voice, her uncanny articulation, and the dynamic shifts with which she enacts Bach's spiritual drama.

On "Home at Last" from Aja (AIFF rip from MCA Records 088 112 056-2), in which the narrator compares himself to Odysseus resisting the deadly song of the Sirens, I was struck by the playing of British jazz pianist and vibist Victor Feldman, who had recorded with Miles Davis, Sonny Rollins, and Quincy Jones. Here, Feldman uses the keyboard as a percussion instrument, accenting the rhythm with surprising force. I marveled at the Morpheus's ability to unravel the complex arrangement and allow me to follow Feldman's piano until the end, especially the way it frames the guitar solo, the most delicious bit of playing in Walter Becker's recorded output.

The review unit arrived with the optional MQA card ($199). Not wanting to get into the endless squabble about the merits of this technology, I will simply report that when the Morpheus performed the final unfold of "Strange Fruit" from Bettye LaVette's Blackbirds (24/96 FLAC MQA stream, Verve/Tidal), the soul singer's aging yet still immensely expressive voice leaped up between the speakers with audibly more of its raspy, colorful personality intact than it did when I disabled the MQA processing. (Here, I was using the AES3 input; for some reason, the MQA card never managed to quite work with the I²S module.)

In my system, the Hermes Digital Bridge replaced a number of more-expensive components: Sonore's opticalRendu and opticalModule, two Sonore Audiophile Linear external power supplies, a Denafrips Iris digital-to-digital converter—the I²S source—and the attendant cables, all of which retail for well over $3000. I was eager to try the Morpheus via its I²S input with this more expensive playback chain.

When I first connected the Denafrips Iris to the Morpheus's I²S input, I heard nothing but silence. Frustratingly, there is no standard for I²S over an Ethernet cable, and the pinouts on the Iris's output don't match the ones on the Morpheus's input. According to Ruijtenberg, if you want to take advantage of the Morpheus's superb I²S input, you have to use the Hermes. Period.

Unsatisfied with this predicament, I reached out to Rob Fritz of Audio Art Cable, the Sonnet retailer who'd sent me the review samples. One of his customers uses a Denafrips Iris with his Morpheus and connects them with a cable from Phasure Audio, another Dutch company, which provides cables with customizable pinouts. This customer, a generous man named Gil Pena, sent me his Phasure ET^2 Cable. Sure enough, the most satisfying playback I squeezed out of the Morpheus was using the Sonore/Denafrips/Phasure/Morpheus playback chain. This combination of source components made music in a noticeably more composed manner: The Hermes sounded a little lightweight and splashy in comparison.

Conclusion
Throughout my time with the Sonnet Morpheus, this thoughtfully designed Dutch DAC continued to upend my assumptions, combining seemingly incompatible virtues: It resolved massive amounts of information while reproducing my favorite music in a natural, embodied manner that never sounded strident. It made listening to even early or poor recordings musically meaningful and fun. The Morpheus may not have made my jaw drop on first look or listen, but over time it offered more insight into my music and the way I listen, and more pleasure, than any digital source I've lived with—some of which cost far more than the Morpheus's eminently reasonable price of $3399.

Note however that this optimal performance was achieved via the I²S input—so I suggest budgeting for the Sonnet Hermes, or for a different source with an I²S output and possibly a custom cable.

I hated handing the Morpheus to the FedEx guy—so much that I ended up buying one.

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Footnote 2: See Herb Reichert's Gramophone Dreams #40. Denafrips has replaced the Terminator with the Terminator II; the price remains the same.