Listening #139

It's going to happen very soon.—Leonard Cohen, "The Great Event"

With a parts list that includes 18 new-old-stock Black Cat capacitors, 16 vintage-style Cosmos potentiometers, two Tango chokes, one Tango power transformer, and some of the loveliest steel casework I've seen on a contemporary product, no one could accuse Noriyuki Miyajima of skimping on the build quality of his company's only power amplifier, the Miyajima Laboratory Model 2010 ($9995, footnote 1). Then again, because the 2010 is an output-transformerless (OTL) tube amplifier, Miyajima-san spent considerably less on iron than would otherwise be the case. Think of the money he saved!

I recently had the pleasure of hosting not one but two samples of the Miyajima 2010: This 7Wpc stereo amplifier can be strapped for mono with a flick of a rear-mounted toggle, to offer a healthy 16Wpc—a whole watt more than the 15W described in 1954 by the late, legendary Peter Walker as sufficient for the average baffle-loaded loudspeaker in the average room. (At the time, Walker suggested 20W as an upper limit.)

I began this journey by using a single Miyajima 2010 as a stereo amp, to drive my pair of DeVore Fidelity Orangutan O/96 loudspeakers—which, some 19 months after reviewing them, I am now in the process of buying. To say that I was impressed by what I heard is an understatement.

The 2010 sounded distinctly open and transparent, yet lacked nothing in the way of color or texture. Throughout Halina Czerny-Stefanska's recording of the Grieg Piano Concerto, with Jan Krenz and the Polish Radio Symphony Orchestra (LP, Eterna 7 20 161), the Miyajima amp endowed the solo instrument with clarity and body and purr, as well as a superb sense of touch and force. Treble notes rang realistically, with considerably more sparkle than through my Shindo Cortese amplifier; in fact, while the 2010 sounded neither bright nor hard, its treble range was remarkably well defined, and the amp, overall, sounded definitely sunny, not dark. Most noticeable of all was the 2010's complete lack of temporal distortion: subtle alterations of attack in Czerny-Stefanska's playing were made far more clear through the Miyajima than through any other amp in house.

The 2010's sparkle also suited it to the great 1960 recording, by Dizzy Gillespie et al, of Cole Porter's "Just One of Those Things," from New Jazz Sounds (LP, Verve MGV-8135). Through the Miyajima, Gillespie's tone, especially in his louder phrases, was delightfully rich and complex, as was that of bassist Ray Brown, whose lines didn't at all lack for power or weight through this sunny amp. In fact, it was while listening to that track, early in my time with the 2010, that I scribbled in my listening notes, "This amp is just about perfect."

A sense of empirical fondness
As was my childhood, my history with OTL amplifiers has been untroubled, marked by neither grave disappointments nor outstanding passions. The idea of making a tube amplifier without an output transformer has always seemed to me a nice enough thing to do, yet I differ from those who make—and a great many who buy—OTL amps in that I lack the conviction that it's the only way the thing should be done.

Similarly, my fondness for the best OTL amps of my experience has been genuine, but it has been a purely empirical fondness, not one motivated by a sense that output transformers have their origins in the devil's toy chest. That distinction—between the things we really like and the things our crazy minds tell us we ought to like—is perhaps something with which many audiophiles should acquaint themselves: Learning it would save considerable amounts of money and distress.

The depth and breadth of Noriyuki Miyajima's passion for OTL operation are unknown to me. For one thing, his company is devoted mostly to the making of phono cartridges—exceptionally good ones, in my opinion—and the proportion of information on his website follows suit. For another, Miyajima-san does not speak English, and the translations of his Japanese into English read like the work of a whimsical robot squirrel.

I asked Robin Wyatt, of Robyatt Audio, the US distributor of products from Miyajima Laboratory, if he could obtain from Miyajima-san a more detailed description of the 2010 amplifier than the one appearing on the company's website. I wondered, in particular, what sort of output circuit the amp employs, and whether the 2010 is capacitively or direct-coupled to the loudspeaker load. Here's the answer I received: "Hello! The circuit of my OTL amplifier is a direct connection type. The phase inversion circuit is a boot strap. I use many condensers for a driver."

The only things I can add to the above are those I observed for myself. Configured as a stereo amplifier, the Miyajima 2010 uses four 6080WC dual-triode tubes per channel, along with one 12AX7 dual-triode and one 12AU7 dual-triode per channel. I can also tell you that the Miyajima 2010 is a fixed-bias, as opposed to auto-bias, amplifier. Its 16 Cosmos potentiometers are all dedicated to the amp's bias-adjustment system: one for each half-tube, working in tandem with two rotary selector switches and a bank of eight test-probe sockets, the latter sporting a removable Plexiglas cover. The user begins by installing shorting plugs and links (included) on the input and output jacks, then uses a digital multitester (not included) to set the correct bias voltage (0.60–0.75V) for each tube. (Georg Simon Ohm reminds us that, because the cathode of each triode is held 1 ohm above ground, bias current, measured in amps, will be precisely equal to bias voltage, measured in volts.) The procedure is mildly tedious but not at all difficult. Based on my experiences, it is also seldom necessary: I didn't have to adjust a single pot.


Still more
Not long after my first experience with the Miyajima 2010, I swapped the DeVore O/96 loudspeakers for my 1966 Altec Valencias, the latter being less well mannered yet having better touch and impact. Beginning again with just a single Miyajima amp, I listened to a piano recording by Arturo Benedetti Michelangeli and was enchanted. From every note of Chopin's Prélude in C-sharp minor (LP, Deutsche Grammophon 2530 236) rang the sound of an instrument played not by an acrobat but by a poet—think of it!—who seemed capable of pulling from each note more living, breathing tone than I expected to hear. Every note bloomed—even the quick ones. Working with my loudspeakers, the Miyajima portrayed so clearly the relationship between artist and music that the listening session was one of rapture, not dissection: Yes, it really was that good.

The Miyajima 2010 was not a sweetening machine. It did not soften the brittle trebles of Aretha Franklin's Lady Soul (LP, Atlantic SD 8176), or of so many other recordings engineered by Tom Dowd for the same label. But neither did it blunt the musical timing that made the ensemble playing in "Chain of Fools" and "Money Won't Change You" so incredibly tight and propulsive.

And although the Miyajima 2010 gave an excellent account of the spatial aspects of stereo recordings, it wasn't an imaging machine, either—at least not in the sense that some listeners might expect. The flutes in Sir Adrian Boult and the London Symphony Orchestra's recording of Vaughan-Williams's Job (LP, EMI ASD 2673) weren't the "precisely" located treble pinpricks that some folks want to hear; rather, they had substance and scale, as in real life.


That recording, in fact, was the first one I tried after switching from one to two Miyajima amplifiers. Changing a single Miyajima 2010 from stereo to mono mode is accomplished with the flip of a toggle switch, after which the same input signal appears at both the left and right input jacks, and the same output appears at both the left and right pairs of loudspeaker terminals. Gain, as expected, increased considerably—which, owing to the 2010's already high gain, required that I operate the volume control of my Shindo Masseto preamplifier near its lowermost limit. That was far from the only difference I heard.

Sometimes I get just a little way into the listening for a review and think, Now I'm done. Now I know everything there is to know about this device. So it was with the Miyajima 2010, which sounded so good as a stereo amplifier that I was almost reluctant to try a pair of them as monoblocks. I'm glad I overcame my reticence: As monoblocks, they provided some of the highest-quality playback I've ever heard in my home.

Some of the distinctions were obvious—such as during Job's first big climax, at 3:11, which played with far greater poise when the power went up, as expected. But before and after, the superiority of the doubled amps was clear. As a 16W mono amp, the 2010 produced an even greater sense of scale, allowing instruments at the center of the stage, in particular, to appear much closer to their real sizes. Colors became more saturated—especially the woodwinds, including the ominous-sounding contrabassoon—and touch and force were taken up another notch, so much so that the orchestra sounded as if it were being played by a single, willful person.

Footnote 1: Miyajima Laboratory, 1-45-111, Katae 5-chome, Jounan-ku, Fufuoka, 814-0142, Japan. US distributor: Robyatt Audio, Tel: (855) 762-9288. Web:

Osgood Crinkly III's picture

The salesman at the hi-end salon where I bought my tubed gear said something that I should have heeded. He said, "Tubes will never sound the same," meaning that from the moment you first turn them on, they start degrading, as opposed to solid state, which is stable and always sounds the same. I love the sound of tubes, but if I could do it over again, I would have made the compromise and purchased solid state.

Buyer beware. Tubed gear requires maintenance, at the very least regular replacement of power output tubes (an expensive proposition when you get into hand-matched pairs and their rarity). Due to the high heat, the gear is not as durable and is more prone to breakdown. Are you willing, buyer, to put up with all this? Are you that committed? Or do you want the peace of mind of being able to turn on your equipment for years without worrying about it not working or sounding the same?

Tubes haven't been manufactured by any large electronics corporation, like Phillips or GE, for decades. The heart of your equipment will rely on tubes either manufactured in a foreign country, like Russia or China, or by small, boutique outfits. Are you ready to live with this? Are you ready to trust these products? Are you ready for the expense?

Just a warning that the romance and allure of tubes doesn't last.

BB's picture

"18 new-old-stock Black Cat capacitors". Harumph! I have rebuilt many vintage tube amplifiers for my friends and for myself. These old-style caps have a notoriously high failure rate. They inevitably become leaky, upsetting tube operating points and creating distortion. I replace them with modern polypropylene or polystyrene caps (Teflon for upscale projects), even if they test OK for now, because they are time bombs. Being NOS, these have still aged and have absorbed atmospheric moisture sitting in a box. They might test OK today, but think of them as being in capacitor hospice. They also add third harmonic distortion, especially the paper-dielectric types, even when fresh. Maybe that's what's desired by Miyajima, but it's not for me. I think the fad of using these old caps is misguided. Many Asian (and American) audiophiles have a reverence for vintage American audio, which has a valid basis, but they sometimes take such a religious stance too far, IMO.

Joseph Reader's picture

I have just read your insightful comments, and would be interested in your opinion regarding the best tube (power) amps currently available. By "best" I mean best-sounding, but I also value things that are reliable and trouble-free.

I love my Conrad-Johnson Premier 11A, my only complaint being that it doesn't sound genuinely GREAT till it is fully warm--i.e., till it has been playing for at least six hours (and preferably about eight hours). I very often don't have time to wait for it.

I'll be grateful for the benefit of your experience. Thanks.

(Of course, the same invitation and request is extended to others here as well.)

revbond's picture

Did you ever solve the hum resulting from the feedback switch?