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Any presumptions of budgetary guilt were proven innocent once the A-014 emerged from its shipping carton with most reassuring heft. This was bespoke quality all around. The obligatory inspection beneath the cover netted Shigeki's customary turret-post construction.
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As far as proper execution for hand-wired circuits goes, things don't get better. The sole exception are the binding posts. With spades they can only be tightened by hand because they lack a hexagonal profile for a wrench. Meanwhile my Zu bananas even under full expansion were still disconcertingly loose. Apparently the central opening exceeds the standard size. I went with spades and my best finger grip.
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With the Takatsuki bottles the output current on the meter measured precisely 90mA for each. The significantly taller thick-glass EML 300BXLS measured 82.5mA and 85mA respectively. Both pentode drivers displayed a rock-solid 200V. Normal operating points are given as between 70 and 90mA for the former, 150 to 300V for the latter. Once any of these valves fall outside their recommended values, replace them. The included 5U4G rectifier on my loaner amp was an NOS Sylvania.
Curiously the meter's four-pole switch lacks any expected bypass position where it wouldn't see music signal. Yamamoto assures us however that it's perfectly safe to operate the meter at will during playback.
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On my 16-ohm 101dB specified Zu Druid V with a standard 2V input signal from the Metrum Hex DAC, the A-014 without signal and Takatsuki bottles was noisy enough to be audible in the listening seat three meters removed. I'm used to zero noise from my single-ended transistor amps. Now I look at such a compromised S/N ratio with very little tolerance. The big Emission Labs valves turned out to be less noisy but didn't eliminate the constant background hum, just reduced its amplitude. This is a routine challenge with direct-heated power triodes particularly when preceded by hi-gain drivers. Most aficionados accept it as par for this course.
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Experimenting with various active valve preamps of 6H30, 12AU7 and 6SN7 flavors for an expected confirmation that this was probably a bad idea netted even more steady-state noise. I likely suffered gain poisoning as counterproductively high amplification factor. Clearly the A-014's attenuator was meant to be used rather than bypassed. That's what I did then.
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With my single-stage single-ended no-feedback SIT-2 stereo amp offering a very similar power rating to be directly competitive and of appeal to the same buyer, I couldn't help but notice that its vertical power Jfet in silicone carbide was quieter, more pellucid and extended on top, faster on transients, more powerful and articulate in the bass, more highly resolved on image specificity and separation and in general more lucid. This confirmed why my personal audiophile journey had years ago moved beyond such valve amps.
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That said I could also appreciate and happily admit how this 300B amp had one advantage which to the right listener could be dominant and make-or-break-it decisive.
It's an observation often made before, routinely under the influence of poetic license. That's because describing this difference easily gets flowery. My chosen key term is fluidity. If you haven't heard it in action before or didn't recognize it as such, you might wonder what, exactly, fluidity sounds like.
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While it's ultimately nonsense, I'd call Chopin on my witness stand. At some point nearly everyone has heard some Chopin piano nocturne or prélude to recognize the—I call it ebb and flow—temporal freedom by which its performer transcends the type of fixed beat metric which a marching band must obey. This isn't about jazzy syncopations which likewise occur before or behind the beat but still at regularly timed intervals. That's still very exacting timing. The Chopin effect stretches and compresses time over phrases and bars in a far more organic, elastic, irregular and thus unpredictable fashion. Its opposite isn't choppiness. It's simply more rigid or mechanical. You'll not recognize it as such until you hear what this type of valve amp does differently. Only then and in hindsight might you accuse your transistor amp (or lesser valve amp) of exhibiting less—or none—of this fluidic elasticity.
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