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Compared to the previous Yamamotos like my A-08s, the new 9 has the 10 centimeter longer wheelbase for 50 width.

The business end mirrors the A-08S - same custom connectors, with very narrow binding post threads to allow for solid hand tightening sans wrench. I do however wish that Yamamoto would include a Teflon insert to fill out the hollow sleeves of their terminal nuts. I'm already using such custom inserts compliments of Aussie importer Warwick Freemantle. Without 'em, spades are caught between shank and sleeve ring. A Teflon insert creates another solid counter surface on the other side for a superior flush fit without canting spades or biting sharply into their surfaces.

The company's trademark belly cover hides audio hand crafting of the very highest order.

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Denuding critical capacitors and encapsulating them inside Ebony sleeves is part of Shigeki Yamamoto's well established custom recipe.

Certain critical resistors are fully heat-sinked. Connections are either hard-wired directly or via gold-plated turret posts.

A bank of power supply filter caps.

Choice Dale resistors (not just the obvious green mini but the rectangular blackies).

If your tube amp isn't built just like this one under its hood yet pretends at ultra ambitions and carries a price tag to twist your 'nads... well, cough and a red face are the appropriate response.

Ditto for the tube sockets. Yamamoto makes its own and as you can see, finer don't exist. These are just some of the obvious reasons for my ongoing open excitement over this brand. As a full-on reference effort, the A-09S is priced at essentially twice its earlier stable mates. Having closely inspected amplifiers over the last 6 years of intensive reviewing, the build and parts quality of Yamamoto lives at the very top. And for that, their prices are very fair. Which doesn't mean cheap. But nobody in their right mind would fail to be impressed what your money buys at Yamamoto.

In the above tube overlay composite, you can admire the unusual sleeve grids of the C3ms. Lacking guide pins, their proper orientation is instead assured with clear silk screen markers on the glass envelopes. Simply pay attention.

The amp goes operational 20 seconds after the power mains lights up. Residual circuit noise is a low 0.5 - 2mV, in my rig a tad higher than Yamamoto's 2wpc 45 SET but still very impressive. Depending on rectifier and output tubes chosen, the auto bias will sit between 65 - 95mA. If this bias diminishes to 55mA over time and due to aging, Yamamoto recommends a tube swap.

For 300B choices, the world in the Czech Republic, Russia, China and the US is your oyster: AVVT; Emission Labs; Euro Audio Team; Cetron; Electro Harmonix; JJ; KR Audio; Sophia Electric; Svetlana; Shuguang; TJ; Valve Art; and Western Electric. For rectifiers, Emission Labs makes a modern beaut. Or go NOS. For the special Teutonic driver tubes, Yamamoto's personal inventory for this amplifier will likely be your very best resource.

If you acquire the A09S with output tubes from Yamamoto, your choice are JJ 300Bs or two EML 300BXLS - in the latter case, the matching rectifier then becomes an EML 5U4 meshie.