MOJO AUDIO MYSTIQUE X

analog signal path in addition to our new extruded chassis and advanced anti-resonance typologies which lower our already incredibly low noise floor resulting in a higher level of performance than any DAC Mojo Audio has ever manufactured.” When I asked Benjamin Zwickel about sound quality differences between the now discontinued X and X SE versions, he opined that “…it would be like the difference between a 12-year-old and an 18year-old bottle of the same whiskey; (X SE is) a bit smoother, a bit more character, a bit more subtlety and nuance.”

In addition to addressing mechanical sources of noise and intermodulation distortion, there are five power supplies dedicated to particular subsystems. In and of itself, multiple power supplies are not unusual, but, in the case of Mystique X SE, all are controlled by Belleson SPX ultra–low noise voltage regulators. In contrast to the now discontinued X edition, other improvements that the X SE carries are ultra–low noise rectification and additional EMI/RFI electromagnetic and radio frequency shielding. Zwickel, electrical engineer, owner, and head honcho at Mojo Audio, sold his turntable in 1995 and “…went on a mission to find the ultimate digital source. It was not long before I learned the notable differences between R-2R and delta–sigma, and became a die hard R-2R fan.” Zwickel pointed out to me, via e–mail, that an R-2R architecture is the only topology to explicitly decode a digital audio stream. Delta-sigma converters interpolate and post– process the signal, then output a “…flawless waveform based on algorithms. Since the algorithms can’t tell the difference between emotional content from bit read errors, the analog output from Delta-Sigma is smooth and

Audio’s discrete Class A J-FET op(erational) amps following Analog Devices' venerable monolithic AD1862 R-2R ladder DAC, the Mystique X SE is a fully Class A, DC–coupled converter, with strategically employed Vishay Z-Foil resistors which minimize inherent self–inductance and capacitance, cryo–treated Kimber VSS VariStrand wire for peak power transfer, Rel-Cap polystyrene film and foil capacitors in the anti–image filter for superior transient response, low loss rhodium–plated Furutech RCA connectors, large size Herbie’s Audio Lab’s elastomer Soft Fat Dot anti–resonance footers, and a Swiss AC power module from Schurter. You may not recognize some or all of those brands and technologies, but be assured they were chosen after a great deal of critical listening, and represent a distinguished calibre for their category.

The Mystique X SE user manual suggests that, “For optimal performance and longevity, we recommend leaving our DACs on 24/7...that’s why the power switch is on the rear.” I understand the thought behind that statement, but my Anthropocene revulsion compels me to consider 20 minutes of warm up entirely sufficient. Speaking of power, Zwickel considers the power supply to be the most important factor in all audio electronics. He embraced an approach that smoothly delivers both voltage and current. Storing current requires large chokes as well as a robust capacitor bank. Here’s Zwickel’s analogy for understanding both voltage and current–delivering capacity: “Think of voltage as the width of a river and current as the speed the water is flowing. So if you are not storing current, as is true with nearly every DAC regardless of price, then the higher the energy required to reproduce a note the farther out of time that note is from other notes. The (Lundahl) LC choke-input power supplies we use in our analog power supplies are the largest, heaviest, most expensive, and least efficient power supply typology possible.”

For my listening evaluations, I mainly used the USB input. Along with all the premium parts mentioned above, the X SE employs JL Sounds’s USB–to–I2S input module. In macOS’s Audio MIDI Setup, it was nice to see the unit listed as “JLsounds Hi-Rez Audio 2.0”. I started things off with the wonderful follow up album by trad jazzers Rachael & Vilray. This year’s I Love A Love Song [Qobuz 88.2, Nonesuch] ends with a bonus track that had me boppin’ in time. The vocals on Let’s Make Love on This Plane are close mic’d but the “full band” behind them was not. The backing musicians were painted with the sound of the room in which they played. Mystique X SE lent that subtle sense of soundstage depth that only comes through with properly low jitter timing in both recording and playback.

A great player was recently lost to us; Geoffrey “Jeff” Beck. Beck’s last major project was his collaboration with Jonny Depp, 18 [Qobuz 48k, Rhino 2022]. On the Lou Reed cover, “Venus In Furs”, Depp’s vocal has the proper amount of close pickup, texturally appropriate condenser mic rasp. The new Mike Watt/Psychic Temple album, Plays Music for Airports [Qobuz 88.2k, Joyful Noise Recordings & BIG EGO Records 2023], encodes a very nice acoustic space. On track two, the almost 18 minute “Music For Bus Stops", I thought, “The soundstage is totally believable except for the drummer. He is unrealistically wide.” By that I meant the drums occupy a very wide perspective, as if you were sitting two feet in front of the drum throne. On track two, it wasn’t until well into the performance that I realized…there are two drummers (!), which accounts for the ample spread of the trap drums.

On track 3 of Martha Argerich Live, Vol. 10 [Qobuz 44.1k, DOREMI 2023], there’s an interesting acoustical event at 29 seconds into the piece. What sounds like a rook comments on the proceedings. I had fallen into Deep Listening mode, and the real world sound effect made sense as it passed by, but then my