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reviewers: Srajan Ebaen & Frederic Beudot
financial interests: click here
source -
27" iMac with 3.4GHz quad-core Intel Core i7, 16GB 1.333MHz RAM, 2TB hard disc, 256GB SSD drive, ADM Radeon HD 6970M with 2GB of GDDR5 memory, OSX 10.8.2, PureMusic 1.88a & Audirvana 1.4.2, Metrum Hex, Cambridge Audio iD100, Apple iPod Classic 160GB - preamps - ModWright LS-100 with Psvane tubes, Esoteric C-03, Bent Audio Tap-X - amplifiers - First Watt SIT2, ModWright KWA100SE, Bakoon AMP-11R - speakers - Aries Cerat Gladius, Zu Audio Druid V & Submission - cables - complete loom of Zu Audio Event, KingRex uArt USB cable with Bakoon BPS-02 - equipment support - Artesania Esoteric double-wide 3-tier with TT glass shelf, Rajasthani solid hardwood console for amps, Track Audio speaker stands - powerline conditioning - GigaWatt PF2 on amps, GigaWatt PC-3 SE Evo on front-end components - sundry accessories - extensive use of Acoustic System Resonators, noise filters and phase inverters - room size - 5m x 11.5m W x D, 2.6m ceiling with exposed wooden cross beams every 60cm, plaster over brick walls, suspended wood floor with Tatami-type throw rugs. The listening space opens into the second storey via a staircase and the kitchen/dining room are behind the main listening chair. The latter is thus positioned in the middle of this open floor plan without the usual nearby back wall.
review component retail: Depends on country, regional VAT and customs to likely be $4.900 in the US

From an Asian maker's recent email:
"This winter is the coldest we've ever had over the past 40 years. The world is changing and unfortunately for the worse. Music I believe can fix our global attitude by changing the minds and thinking of people in these greedy times. Our own sales have dropped by 25% over the last 6 months which probably reflects the global crisis. We have to overcome this by making more affordable products of better quality."

Though Shigeki Yamamoto's English is too limited and my own Japanese zero to conduct real conversations by email, it's fair to assume he'd have similar comments. It's certain to be the very same rational that's now been put to good use in his very latest A-014 300B integrated amplifier.

It's about half today what the equally 300B-fitted A-09s demanded 5 years ago when I reviewed it. Let's call that a timely concession to current economics. To experience quality SET sound it's also a welcoming invite at a broader audience. As they rightly say, hardship so often becomes the true mother of invention.

Here minor cosmetic concession is molded Cherry Ply for the enclosure and and gold-painted 2mm steel with exposed screw heads for the deck and base. This says sayonara to the vacuum-impregnated solid Cherry wood that's been established Yamamoto practice. The passive volume control eliminates a preamplifier for single-source systems and thus cuts out related expenses. But the A-014 is still a proper no-feedback valve-rectified purist SET. And it still sports a driver stage with Shigeki's favored denuded 10.000-hour NOS Siemens C3m mesh-plate pentodes from his personal cache of 1960's German postal inventory.

A hi-B cut-core output transformer with Teflon-insulated windings and 0.1mm core layers, an R-core mains transformer with discrete secondaries for the high-voltage and DC heater circuits and two chokes make up the onboard iron tucked inside the curvy cover. Output tabs at 16Ω accommodate vintage speakers like Altec 604E or Zu's very current Druid V. 8Ω tabs are provided for all others. The absence of 4Ω terminals indicates what not to do. The auto-bias circuit is said to handle most all 300B types including newer-spec Emission Labs variants with 2A heater current. To maintain cost effectiveness the unit of course ships stock with Slovakian JJ power triodes.

For improved sonics Shigeki opted against a hum-nulling pot. Heating of the direct-heated triodes is by DC and cathode current feedback is said to be minimal. Speaker coupling is via polypropylene film capacitors. The driver and output stages run discrete power supplies, the former a constant-voltage Mosfet-based circuit.

Yamamoto's signature meter gained a very useful added function. It now allows verification of not only output bias current but driver voltage. This makes for convenient indication of tube life/performance for C3m and 300B to prevent unnecessary but costly returns to the maker or dealer when the only culprit for bad or no sound is an out-of-spec bottle.

Tube sockets are the company's own acclaimed Teflon/bronze units and the i/o terminals on the back are Yamamoto's own as well. For guts the A-014 gets a 3mm bakelite board attached directly to the steel casing and populated with point-to-point parts. Here most precision resistors are sourced from Dale. Power delivery is a typical 8wpc for this type of circuit, residual noise is a claimed 0.8mV, response is 15Hz to 22kHz -3dB, dimensions are 500 x 294 x 208mm WxDxH and weight is 16.2kg.