Miyajima Lab Wo-1 preamplifier

A phenomenon formerly unique to Japan, which in recent years has been emulated in cities around the world, is the jazz café (known as jazz kissa in Japan; footnote 1), where salarymen can find respite from their hectic lives, loosen their ties, and enjoy hi-fi jazz over coffee or a drink. Jazz kissaten are typically charming, smaller shops, traditionally furnished and paneled in beautiful wood, which serve superb artisan coffee in artful ceramic cups.

Such respect for artistry, craftsmanship, and attention to detail—the Japanese word is shokunin—is reflected in many aspects of Japanese life. This is where you find double handrails to accommodate people of different heights, intricate, ornately designed manhole covers, and bento lunch boxes with hand-carved vegetable figurines. While upholding strict conformity to societal norms, the Japanese highly value creative individualism. This shokunin mindset underlies their reverence for artisanal expression—and their love for jazz.

Japanese audio, much like jazz kissaten, reflects the shokunin mindset: craftsmanship pursued with both pride and humility. Consequently, tube amplifiers from established Japanese brands—AirTight, Kondo, Leben, Luxman, Shindo, Yamamoto—have been held in high esteem for decades. Manufacturers less well-known in the West—Audio Tekne, Spec, Triode Labs, and Takatsuki/Alex Sound—are just as well-respected. Japanese cartridges, too—from brands such as Audio Technica, Denon, Hana/Etsuro Urushi, Ikeda Labs, Koetsu, Miyabi Labs, Nagaoka, Shelter Audio, and Sumiko—are widely revered.

Tube technology found favor in the 1950s among such Japanese advocates of low-power amplification as Kei Ikeda and Nobu Shishido of Wavac. They in turn inspired Jean Hiraga, a French-Japanese engineer and editor of L’Audiophile, who wrote the 1990 book Initiation aux Amplis à Tubes (Introduction to Tube Amps). Hiraga was “the first guy in the Western world to promote low-power amps and high-efficiency speakers,” Joe Roberts, former editor of the influential magazine Sound Practices, told me in an interview (footnote 2). “The presence and influence of esoteric Japanese phono technology, from the ’80s until now, is evidenced in the enduring popularity of Micro Seiki, Fidelity Research, and Grace, to name a few. Miyajima is in the tradition of taking things a step further.”

The shop

Miyajima Laboratory was founded on March 27, 1980, by Noriyuki Miyajima, initially as an audio store. The company operates out of a small, three-story building in the ancient port city of Fukuoka in the south of Japan, employing six people.

Miyajima’s objective, their “Profile” webpage states, is to “advance the design and production of the finest-sounding analog audio components”; the company’s core philosophy is to “skillfully build superior audio components that will reproduce recorded sound so faithfully, that the artists’ personality and the emotions in their music are perfectly expressed.” Miyajima’s first product was a 6B4G mono amplifier. Not long after, a series of stereo cartridges was released—the Takumi, Saboten, Carbon, Shilabe, Kansui, Madake, and Destiny—garnering global acclaim and consistently listing in Class A of Stereophile’s Recommended Components list.

In addition to cartridges, Miyajima currently produces four step-up transformers (SUTs), two headphone amplifiers, a pair of large, open-baffle loudspeakers, the Model 2020 OTL power amplifier (footnote 3), and two preamplifiers: the EC-5 and the Wo-1, which is the subject of this review.

“Unique hand-made Japanese artisanal”

The $21,500 Wo-1 (short for “World-1″) stands 6.9″ tall, 18.9″ wide, and 18.1” deep and weighs 46.3lb. Its front and back panels are made of aluminum, as are its control knobs. The sides, top, and bottom sections are steel. Two sturdy steel handles are mounted on each side of the front panel, so repositioning the preamp is a breeze. Knob indices and other markings are engraved on the faceplate, including—with obvious pride—the words heading this section.

The Wo-1 is built to battleship-worthy standards. The tubes, chokes, capacitors, and transformers are all affixed to a massive steel plate with point-to-point, Miyajima-made copper wiring below. Four pairs of tubes power the Wo-1: a pair of globe-bottle Psvane 6SN7 SE tubes and a pair of NOS Telefunken 12AU7 tubes (both pairs controlling line-level signal), two NOS Sylvania 6XB7GT tubes (output), and a pair of NOS Heath/Mullard E80F tubes (in the phono stage). A large SEL power transformer, four SEL chokes, and 10 large CDE capacitors are arrayed to the right of the tubes.

In operation, the Wo-1 is simplicity itself. On the left are a glass current meter and associated controls, which enable biasing of the 6SN7 tubes; on the right are input and mode (channel and gain) selectors and volume and power knobs. The no-nonsense back panel includes an IEC jack and a fuse holder, two pairs of output jacks (RCA), and five pairs of input jacks (RCA).

In a Google Translate–mediated email exchange with Noriyuki Miyajima, I asked about the volume control. Miyajima explained that in the Wo-1, “no audio signal passes through the resistors. I wanted to avoid using the commonly used volume resistors. It’s a low impedance and high voltage design which gives a very dynamic and powerful presentation. I want a powerful, roaring sound.”

US distributor Robin Wyatt, of Robyatt Audio, elaborated. “It’s a gain-tracking device, not a potentiometer or attenuator. As you turn the volume knob, it changes the incoming gain via a tube circuit. You set the input gain feeding the amp [and adjust it] at any point … as needed, with no volume pot in the circuit.”

Setup

The Wo-1’s handles made hauling it around my listening crib and sliding it into my Salamander rack a cinch. I used Thorens and VPI turntables with a variety of MC cartridges wired into Tavish Audio, Manley Labs, and Pathos phono stages. I compared the Wo-1 to Sugden and Shindo Allegro preamplifiers and a Mytek Brooklyn with preamp features. I used Shindo Haut-Brion and Mytek Brooklyn power amplifiers to drive Volti Audio Razz and Harbeth Super HL5plus XD loudspeakers. AudioQuest, Analysis Plus, Triode Wire Labs, and Shindo cabling carried audio messages. Robin Wyatt biased the amp upon arrival. After that, I didn’t touch the bias settings.

From experience, I learned to spin the gain knob back and forth with the power off. When I didn’t, the preamp emitted loud, unfriendly pops on startup and whenever I increased the gain. Silicone spray didn’t help, but my daily rotation ritual did.

Footnote 1: Jazz Kissa 2014 and a sequel titled Jazz Kissa 2015–2019, from Japanese publisher Jazz City, present a photographic essay of nearly 200 of these much-loved establishments from across Japan.

Footnote 2: More about Jean Hiraga can be found in Keith Howard’s article “Euphonic Distortion: Naughty but Nice?” from April 2006.

Footnote 3: Model 2020’s predecessor, model 2010, was reviewed by Art Dudley in July 2014.

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Miyajima Laboratory

4-3-25, Chayama, Jounan-ku

Fukuoka City, Fukuoka, 814-0111

Japan

[email protected]

81-92-801-6660

miyajima-lab.com

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Tube Amplification Moves West
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