Yamamoto Sound Craft single stereo amplifier

Single amplifier that adopts the 300B that occupies the position as reference tube of modern vacuum tube amplifier to the output tube
The basic circuit adopts a self-bias method of CR coupling using a five-pole tube for the voltage amplification part. The amplification part does not use negative feedback, but has obtained a natural sound field by utilizing the basic characteristics of the non-feedback method.
New cut-core transformers are used for all transformers to achieve better sound than toroidal cores.

The toroidal core transformer used for power transformers, output transformers, and chalk coils was of excellent sound quality, but it lacked stability, so the company changed all transformers to the cut core type of the new design, resulting in a more stable and dynamic sound than the toroidal core transformer.

The standard is sold separately by output pipe so that you can choose the output tube freely, Emission Lab can be selected

It is designed so that most of the 300B of each company can be replaced and no adjustment is required. No adjustment, such as ham balance, can be achieved without adjustment.
Double wave rectification DC ignition circuits with Schottky diodes to maximize 300B capabilities
The rectifier adopts a high-performance Schottky diode of IR in the United States that supports large currents. In addition, a small smooth condenser gives a speedy sound. We also try to improve freshness by simplifying the circuit.
High-performance German high-performance tube C3m is adopted for the first stage pipe, and high-quality driver stage is configured with low noise.
The C3m tube is characterized by its excellent electrical properties and very beautiful sound quality. The metal case as a loctal tube is removed and used as a glass tube. This makes the sound quality even more natural.
Wood-based materials are used for chassis, and aluminum alloy transcubbers are combined to create a new and beautiful design.

It is a material that is excellent in strength and electrically solidified by laminating a thin single plate of cherry wood and containing phenolic resin. The transcover is beautifully finished using a 2mm thick champagne gold aluminum alloy with a cherry blossom side plate and a durable almite plating.
Fully adopted in-house Teflon sockets that are highly valued worldwide for their high performance and reliability
The socket is designed to hold the legs of the vacuum tube properly with a slit. Therefore, when the vacuum tube is attached to the socket, the foot of the vacuum tube is held firmly, there is no sticking, and the effect of external vibration on the vacuum tube is prevented.
DALE has good sound resistance, and polypyrene film condenser with less distortion is used for condenser.
For large resistors, we use non-inductive metal clad type, for medium capacity type, high precision winding type, for small capacity type, metal coating resistance and large surface mounting type resistance. Polypropylene capacitors are filled with high-strength epoxy resin adhesive in ebony and bakelite cases, increasing the strength of the capacitor and further improving the sound quality.

Our original pin jack for chrome copper is used for input terminal, and pure copper speaker terminal is adopted for speaker terminal

The output terminal is pure copper shaving gold plated with a large terminal with Teflon insulation. It is also possible to connect a super-thick speaker cable with a thickness of 8mm. The speaker terminal is only the 8Ω output terminal, 4Ω there is nothing wrong with using the 16Ω speaker. However, the maximum output will be lowered in either case. If it is the maximum output of the 8W, it will be the 4-6W output.
Beautifully rigid African ebony round bar on the legs
The legs are fixed directly to the chassis made of Comprit to gain strength and resonance, and support the overall weight accurately.
High-quality wire material is used for power cable, and a hospital grade gold plated terminal is used for plug.
When the quality of the vacuum tube amplifier improves, changes in sound quality due to the power cable become sensitive. Please enjoy the change of sound by power cable.

Very vivid tone. Excellent projection power from room to listening seat.
This amplifier is quite close to the auditory aesthetic of the A-08S. In many ways, the fragrance of EML solid plate 45 is taken over to the 300B. The tendency is to be thicker, longer and more luscious. 。 In short, many amplifiers, although considered typical of 300B, differ greatly from actual 300B sounds. The A-09S is not merely a quadrupling of the same sound as A-08S 45. The speaker feels surprisingly close, but is thick and not so bright. For those who are a little lacking in color at 45 and feel energetic but too thin, the 300B brothers give color and fresh texture. Very sophisticated timbre with a very three-dimensional sound field, sharp clarity, advanced direct that does not stick to 45 sounds (these are far beyond 45 sounds). The drive and gain of the A-09S were unexpectedly powerful, and were found when connecting a wide red deck to the 91dB DeVore Fidelity Nines. At 2:30, the volume of the preamplifier with a gain of 12dB, the speaker was much more dynamic than many high-power amplifiers.
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The reproduction sound is a rich pattern that meets energy within a moderate band, reflecting the timbre and sound quality of the wooden enclosure.
Although the warmth of the vacuum tube can be felt as an underflow, the sound tendency with clarity as the axis is impressive. The stringed instrument has a good expression,
The good standing of the keyboard instrument is also impressive to make you feel exhilarated. The song is made to feel the warmth of the voice behind it, but with a clear sense of occurrence.