Air Tight Opus-1 Ermitage Moving-Coil Cartridge

Magnum Opus, Indeed

Equipment report
Air Tight Opus-1
Air Tight Opus-1 Ermitage Moving-Coil Cartridge

Though Air Tight’s Atsushi Miura may not be well known to American audiophiles, this modest, gentle, dignified man has come to epitomize the Japanese high end for me. Formerly the head of Lux Audio—Japan’s oldest electronics company—Mr. Miura founded A & M Ltd. (the parent company of Air Tight) in 1986 solely “to contribute something to the development of world audio culture.” At the time, semiconductors were the kings in Japanese electronics; analog had been pronounced dead; home-theater and car stereo were booming, and Mr. Miura’s company, Lux Audio, had been sold to Alpine, where this former bastion of high-end tube electronics would be turned into yet another solid-state marque. Wealthy, middle-aged, and successful, Mr. Miura had no commercial reason to continue in the high-end-audio business. And yet he did, because, in his own words, he felt that high-end audio was “losing its original peerless ‘dream’ in the general shift from valves to transistors.”

With his engineering design partner (and A & M’s co-founder) Masami Ishiguro, Mr. Miura began work on the original Air Tight ATM-1—a 36Wpc, 6CA7-based tube amplifier of extraordinary build-quality (Hashimoto transformers, hand-soldered point-to-point wiring) and drop-dead-gorgeous looks. Rather like a Japanese take on the Marantz 8B (but much more beautiful), the ATM-1 was followed by the Marantz 9-like ATM-3 and ATM-4 and many other beam-pentode and single-ended-triode amplifiers. True to his ideals, each of Mr. Miura’s amplifiers pays homage to the Golden Age of High Fidelity while improving on Golden Age sonics.

For Mr. Miura, LPs are part and parcel of the “peerless dream” that animated the hi-fi industry in its prime. So it was not surprising that, in 2006, he and his colleague, Y. Matsudaira, developed an Air Tight phono cartridge based on Mr. Matsudaira’s research at My Sonics Labs. (The “My” in My Sonics Labs are Y. Matsudaira’s initials arranged in the traditional Japanese fashion—last name first. Just for the record “A & M” are Atsushi Miura’s initials, arranged in Western fashion.)

For forty years, Mr. Matsudaira has been, perhaps, the most illustrious designer of moving-coil cartridges in the Far East, having devised celebrated cartridges for Supex, Koetsu, and Miyabi, among many other marques. In 2006, he claimed to have solved a longstanding technical problem: how to achieve high energy from a low-impedance circuit. The problem in a nutshell was this: A higher-output (i.e. higher-impedance) moving-coil cartridge (on the order of 0.3 to 0.7mV output) typically has more coil windings, which leads to higher energy, richer tone color, and increased “liveliness,” but lower resolution of fine detail; a lower output (lower-impedance) moving-coil cartridge (on the order of 0.1 to 0.25mV output) has fewer coil windings, which leads to higher resolution and transparency but reduced density of tone color and dynamic clout. For thirty years, Mr. Matsudaira has written, nothing substantial was done to solve this “output voltage versus internal impedance puzzle.” You could have high energy and color or high resolution and transparency, but not both.

After years of exhaustive research, Mr. Matsudaira discovered a way to minimize coil windings (for higher resolution) and increase output (for higher energy) simultaneously. Many factors played into the design of Mr. Matsudaira’s new cartridge—including the geometry of the stylus and the design of the cantilever and cartridge body—but the fundamental breakthrough was the development of an ultra-high-µ core material (named SH-µX), which, because of its high saturation flux density (three times higher than conventional high-µ materials) allowed for a dramatic reduction in the number of coil windings (thus suppressing core-saturation losses and lowering impedance), while also generating the high voltage necessary to energize music from the top octaves to the bottom ones.

Mr. Matsudaira’s original design was released by Air Tight as the PC-1, and was an immediate critical and commercial success, primarily because it did exactly what it claimed to do—lowered noise and coloration and greatly increased resolution and energy. Details were clearer, timbres were truer, air was more plentiful, dynamics were more lifelike, and stage width, depth, and height were expanded in comparison with other moving-coil cartridges then on the market.

Several years later, Mr. Miura released Mr. Matsudaira’s improved version of the PC-1, the PC-1 Supreme, which was said to reduce internal impedance even further (down to 1 ohm, thanks to 40% fewer windings), as well as improve the cartridge body’s susceptibility to resonance. The sonic results of these and other changes, according to Air Tight, were improved bandwidth, dynamic range, transient response, and phase behavior. And in my review of the PC-1 Supreme I confirmed those claims. To quote my conclusion: “The new cartridge goes lower with much better timing, focus, and resolution, goes higher with greater incisiveness, detail, and speed, plays big dynamic passages with greater power and control, and stages with even greater width and depth and focus than the PC-1 (which, let me remind you, was and is no slouch in any of these regards). It is also a much more neutral cartridge than the PC-1, which sounds a bit dark (a bit weighted toward the bass and softened in the treble) by comparison, with considerably higher low-level resolution at both of the frequency extremes (and in the middle).”

Even though it was quite a bit more expensive than the PC-1, the PC-1 Supreme was and is a top-seller (Robert uses one as his reference), and is widely regarded as one of the über-cartridges currently on the market. [One of the world’s most famous speaker designers visited me to set up his flagship speaker, and after hearing the PC-1 Supreme, bought two for his own use.—RH]