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300B vs. VT52: While not as apples to apples a comparison as Craig Uthus' Eddie Current Balancing Act preamp allows between 45/2A3 and 300B/PX4 (same circuit and transformers, altered heater/bias values), comparing two top amplifiers from the same designer dedicated to very specific output glass was as close as I could get. The A-09S was fitted with my favorite Create Audio/Synergy 300Bs and EML's 5U4G rectifier. The chain thus was iMac streaming AIFF files through Pure Music 1.7 in memory play into the Burson Audio HA160D set to roughly 2V out via Entreq USB cable. From there the now analog signal traveled down Franck Tchang's LiveLine cable into the Tap X passive, thence into either amp via more LiveLine into Franck Tchang's speakers via his matching speaker leads.

Obviously those without ultra-efficient hornspeakers (or who do not use flea amps in bandwidth-limited active-crossover mode into efficient dedicated drivers) should or would abstain from bombastic orchestral music, power Rock and house-style slam beats. That's simply not on the menu. To explore more appropriate aural aromas while still on a Turkish kick, violin compliments of Adnan Karaduman's Meçhul [Kalan] and Murat Sakaryali's My Violin [Mega Müzik] got on the menu before the Russians by way of Olesksandr Klimas, Sergey Erdenko and Vladimir Bessonov took over.

With both amps powered up for a good hour, swapping merely involved unplugging speaker leads first, then moving interconnects, re-attaching speaker cables and compensating for a small output difference on the preamp. The outcome was plain. The 300B amp had more amplitude below 80Hz; the VT52 had slightly more emphasis around 150Hz with the clearly more lit-up top end and the lither steeper transients. On-string action with the less powerful amp became more obvious and finely gradated. Celli in particular won more bel canto quality (for not your grandfather's cello, give Uğur Işik's Cello Invocations a spin [Kalan]). Most profoundly, the VT52's staging was clearly the more hologrammatic and distinctly separated/layered. The 300Bs where the Create Audio bottles already are top of their class in this still were fuzzier, thicker, rounder, stickier and more compacted.

In matters of treble elucidation, decays, tone modulations and spatial light changes, the VT52s were the more sophisticated and insightful performers. On bass control disregarding a small upper bass saddle they seemed slightly more talented but lost in raw output to the 300Bs which painted a stronger foundation. While the 8 watts of the A09S have sufficient headroom for my habits to not run afoul of clipping into the Tango speakers, the 3 watts of the A-010 did not. It was time to give unto Caesar, raid the closet under the stairs and move in the Zu Essence.

Round N°.2: With a claimed 97dB/12-ohm sensitivity for the 2-driver 1.5-way Zu, matched listening levels to the 91dB/8-ohm 5-driver 3-way Tango only had the Tap's autoformers at 5dB lower windings. Even so clipping—which in its mildest form simply sounds dirty—now was banished for good from my customary levels (I'm sure undue enthusiasm would have put a lie to that but I have neighbors). The rather less challenging bass system of the Zus was clearly in the Yamamoto's favor too. Some presence region finesse and tinkle was left behind with the Esotar clone tweeter and triple resonators of the Tangos but Zu's trademark meatiness clearly made the flea-power amp sound beefier if no longer as preternaturally 3D.

Having very recently taken first stabs at the Spatial/Emerald Physic setup with comprehensive speaker/room correction performed directly on the digital files—albeit requiring digital attenuation to the tune of 50dB—I found the Yamamoto/Zu rig to be vastly more enjoyable and tune/toneful. Where the DSP'd system has broader bandwidth, greater linearity and for all intents and purposes unlimited SPL potential, it also sounded dry-cleaned, starched, pale, flat and - well, boring. I was strongly rooting for it. The basic concept appeals to how I believe common problems will one day be solved. Alas for now, the comparatively Stone Age technology of big paper-cone widebanders without crossover and NOS direct-heated triodes trounced the smart modern stuff on emotional conviction, tone density, incarnation factor and juice.

With Zu's chewy less acutely resolved upper midrange the VT52 amp was better matched than the thicker less lit-up 300Bs. Those caused a certain level of opacity or fuzz. While a head-to-head comparison against the A-08s would have been trick, you already know I no longer had it. Still, I distinctly recall comparing it to the A-09s. Like the 45, the VT52 had that particular crystallized hallucinatory hologrammatic thang going but seemed to borrow just a bit more density and downward weightiness from the 300B. A good example for this were the exotic voices of Paula Cole, Sussan Deyhim, Abdoulaye Diabaté, Hassan Hakmoun, Yungchen Lhamo and Vishal Vaid abetted by superb instrumentals on viola, clarinet, soprano sax, whistle, flutes, koto, oud, bass and mega percussion plus synthesizer on Jamshied Sharifi's terrific second solo album One* [Ceres Records].


For world music freaks keen on well-mastered guaranteed recos, both Sharifi's A Prayer for the Soul of Layla and One are golden tickets. Think Mercan Dede deep in the deserts of Northern Africa and you have the general drift.

With soundtrack evocativeness—far more varied than the beautiful and actual Kebelek/Butterfly soundtrack of Omar Faruk Tekbilek and Brian Keane—and heavy tribal drum grooves, One offers a wealth of exotic timbres, rhythmic interplay, funky bass lines and potent rumble. Where the showing over the Tango had me stay clear of such fare and actually question whether it was permissible, the Zu Essence completely turned the tables on any doubtful reluctance and instead begged for conscientious debauchery. If drum thunder compressed slightly, I didn't notice. Things really came together here. Were the Zu my only speaker, I'd ask Shigeki to let me trade in my costlier A-09S for the A-010. Such are the temptations of reviewing. But the VT52's power limits make it a far more conditional proposition requiring very special speakers to not become a girl plus guitar pony. That's not the kind of speaker reviewers can focus on lest they end up writing for an audience of a few hundred. Were sense and sensibility out of the picture, the A-010 would stay and bye-bye 300Bs. Back on track.

Highlights: Soundstage sorting with truly terrific delineation into specific depths/distances from the listener fanned out over a very broad swath of scenery is one. Near 'transistory' transient cleanliness is another. Because there's more stuff between the notes than with solid state, the effect is quite different. Yet anything rapid and steely like pearlescent qanun or harp glissandi; anything blatty like trombone staccatos; crisp like cajon tattoos; fiery like Flamenco or Jazz Manouche guitar runs; wiry like tautly stretched long strings plucked fiercely or hammered violently like Cuban piano... none of it seemed shortchanged. It simply wasn't as lit up against a jet black nothing as my FirstWatt F5 or J2 amps do it. Nor was it as finely filigreed and feathered out in the treble but in trade it was distinctly richer on tone textures and more evolved in connective tissue. Dynamic swells held together surprisingly well but on raw startle factor and jumpiness I've heard more adrenaline elsewhere. This could require more headroom or rather more efficient transducers than I had on hand.

In tandem with spatial dimensionality, it was tonal texturizing without cloying thickness or patination which I heard as the other great strength of this amp. It combines crystallization (which is clear but cold, translucent but hard) with blood which has viscosity and warmth. In the end, walking that polarity with such surety is what I'd single out as the special attraction or auroma of the Yamamoto A-010. Yes there is some mild self noise; yes power is minuscule to seriously compress rational speaker choices; yes the output tubes are exotic leftovers without currently made replacements. Yes and yes again as Rumi would have said (and "No!" every rationalist).

None of it makes for a smart Swiss army-knife choice especially if you can only own one amp (and who really needs more?). But then nobody in their right mind would confuse Yamamoto with a mainstream provider or this particular offering with anything but an extreme niche product for real aficionados, i.e. folks properly prepped on expectations and hifi environment.

With all that boiler-plate stuff crossed off, there remains the very real potential for magic when all the moons align. Is it the quad rectifiers and transistorized parts in the power supply which give this amp its extra speed? Is it primarily the combination of driver and output tube? This line of questioning leads nowhere. Only the designer knows if he's played endless substitution games before settling on finals.

If only the amp had thrice the power for that extra bit of headroom. That's the core crux. Folks like Shigeki who make it their business sampling forgotten tubes routinely end up with micro-power specimens. I'm sure there's very good reason. It usually goes to the tune of more powerful triodes don't sound as sophisticated. To participate in this game then requires paying the piper. That's providing properly matched speakers and not feeding the system any music that goes beyond what it'll handle. Remember the orchids. They need just the right light, don't bloom year 'round, look very common when not but when in full bloom are simply classy, exotic, mysterious and gorgeous.

I'll end with what could seem foregone conclusion given the intro. Still, having owned Yamamoto's 45 amp and now heard the VT52, I'll comfortable sign on the dotted line of Super 45. It's not the extra watt that makes it so. It's being equally crystalline as the 45 whilst adding fleshier density and pressurization plus what at least if memory serves seems to be more assured footing and control down low. For what it's worth, that's my first-timer read on the VT52 as presented in Shigeki's circuit. I consider it a real privilege having heard this very exotic specimen. With more than half of the type of music I fancy and my apparently tailor-made Zu Essence speakers, it was a very memorable encounter. It could be one you're inclined to duplicate if the very real associated conditions are practical. When properly catered to, the A-010 really did turn conscientious debauchery in my digs. Thanks to maniacs like Yamamoto who explore the narrow byways for the sake of the very few!
Quality of packing: Very good.
Reusability of packing: A few times.
Ease of unpacking/repacking: A cinch.
Condition of component received: Flawless as anything from Yamamoto thus far.
Completeness of delivery: Perfect .
Website comments: Limited by software-generated Japanese to English translations.
Human interactions: Always directly with the designer and prompt.
Pricing: Considering extreme niche status and execution, affordable luxury.
Final comments & suggestions: High input sensitivity makes preamp gain not only redundant but potentially noisy. This amp is a perfect candidate for TVC, AVCs or resistive passives. 3-watt power limit imposes wholesale restrictions on speaker choices. When used properly however, this is close to a best-case scenario for a direct-heated no-feedback single-ended triode amp intended to drive passive speakers. If you own Yamamoto's A-08s (which presupposes your system is keenly attuned to its limitations), the A-010 would most assuredly be a worthwhile upgrade to consider.
Yamamoto SoundCraft website