It has all the advantages of coherence from its widebander nature. It's cut from one cloth unadulterated by a crossover or character shift for remarkable purity that defines it as a superior pass-through component. Over the course of the review, the M+D showed chameleon traits to take on the attributes of my DAC settings and cable looms. With the Audio Art Cable loom, the Ultrumax emphasized speed, resolving power and phenomenal dynamic contrast. Arkana Physical Research shifted to a meatier presentation, highlighting imaging, placement and 3D dimensionality. Character identification of the Ultrumax became a matter of distillation. It behaved more in the fashion of best thin-film transducers so I'll draw my comparisons there. In terms of full-range ribbon tech, the M1-ST leaned tonally a little more to an Apogee Diva than Duetta Signature. In electrostatic terms, the equivalent benchmarks were more Martin Logan than Acoustat or Quad.

The Ultrumax with its DM-9a driver is a very new breed of AMT so carves out unique territory in how it handles dynamics and space. I'll resort again to panel comparisons as the most relatable. Image size and soundstage cover were very much like a smaller Magnepan. Instruments and hall scale were life-size rather than a population of miniatures in a diorama, with excellent boundary delineation. Welcome to panel chops in a pint-sized package. The presentation was immersive with Cinerama width and a fair sense of height especially when operating in the equilateral nearfield. Farfield listening shifted perspective to more observational so farther back in the hall. Differentiation of instrument scale and placement was spectacular. Instruments closer to the microphone simply sounded closer than instruments that were farther away so not bigger versus smaller. The Ultrumax played these virtues in the farthest reaches of the best of high-end panel speakers.

Dynamics and resolving power were first rate. On microdynamic ability the Ultrumax surpassed my former Apogee ribbons. It was simply quicker to pick up fine detail and considerably cleaner, exhibiting an extremely low noise floor that ranked among the finest if not best I've encountered from either ribbons or top-line ESL. Does it represent a new standard? I'll leave it to future reviewers to provide a definitive conclusion.

But there was more. Low-level dynamics and low mechanical noise were not the end of the story. The M1-ST was also blazingly responsive, shifting instantaneously from micro to macro dynamics with lightning agility. I also teased a fresh twist for an AMT so here it is. The Ultrumax exhibited something I haven't encountered in an AMT, ribbon or panel before, an intense dynamic thrust I'll call propulsive mass. If you recognize that property from hornspeakers, transfer the concept without the coloration. Percussion, winds and strings all benefited but especially horns reached lifelike stature and energy. To hear what that fuss was about, here are a few standouts. Sonic spectaculars by the All Star Percussion Ensemble like "Carmen Fantasy" on the FIM's Top 12 in Gold rendered astonishingly lifelike, cavorting lithe and lively yet solid and textured. Reference Recordings' tumultuous Big Band Bassie or From the Age of Swing were breathtaking in their dynamic bounce and intensity. A heart stopper was "The Preachers of Crimetheus – Finale: Special Deliverance" from Telarc's PDQ Bach: 1712 Overture. It was dizzying in reckless abandon with an air horn solo that was simply terrifying. All of this hit new character territory for an AMT to champion the M1-ST's position as leading-edge transducer of its breed.