Yamamoto Sound Craft"2A3" single stereo amplifier new model A-011SS

The A-08SS won numerous awards.Yamamoto Sound CraftHowever, the design concept andHigh-FidelityThe A-011SS is a model developed specifically for the 2A3 vacuum tube by further refining the technology. This 4W output will confidently drive even medium-efficiency speakers, where the A-08SS's 2W output was insufficient. Even with medium efficiency speakers, you can fully enjoy the rich midrange and sound field expression unique to the 2A3.
2A3 is produced in large numbers all over the world, from vintage tubes to current brand new ones, and it is also attractive that it is relatively easy to obtain. A-011SS is designed to replace most 2A3s without any troublesome adjustments. There is no need to adjust the hum, allowing for quiet and clear playback. It truly deserves to be called the "2A3 reference machine."
The 2A3's transparency, emotional midrange, and powerful sound reproduce music even more vividly.

Precise, clear sound with Vishay thin film resistors

Widely used Thin Film Resistors from Vishay, USA.
Compared to general carbon/metal film resistors, the error is 0.1% and the temperature coefficient is 10 to 25 ppm/°C, which is an order of magnitude better.
It suppresses fluctuations in the resistance value even with large amplitudes and transients in music signals, achieving accurate tone without muddiness and a high sense of silence (noise is approximately 1/10 of that of general metal films).

SiC Schottky diode + independent power supply circuit

An 80 rectifier tube is used to rectify the power supply for the output stage, and the driver stage is rectified by an Infineon SiC Schottky diode as an independent power supply.
A clean power supply with no spike current enhances the transparency and three-dimensional effect of minute signals, making localization and depth expression even clearer.

DC ignition + ultra-low impedance rectification

All 2A3/717A heaters are driven by double-wave rectified DC ignition.
Ultra-low-loss Schottky diode suppresses power supply impedance and achieves fast startup and sense of energy.
No hum balancer is used, which can cause sound quality deterioration, and the circuit design suppresses hum.

Hi-B Material Cut-Core Power/Output Transformers

Both the power and output transformers adopt Hi-B (High-B) type cut cores.
The output transformer uses a custom 100 µm core material wound with PTFE (fluororesin) insulating paper, achieving wide bandwidth, low loss, and high linearity.
It delivers tight low frequencies, clear high harmonic tones, and a detailed soundstage.

High S/N Design with Carefully Selected Parts

Both signal and power sections are primarily composed of polypropylene film capacitors.
The use of electrolytic (chemical) capacitors, which are disadvantageous for sound quality, is minimized as much as possible.
Resistors are carefully selected high-evaluation components such as DALE metal-clad and Vishay high-capacity SMD types.

Silver-Plated Copper Wire + Fluororesin Sockets

All internal wiring uses MIL-standard silver-plated copper wire (PTFE insulated), reducing oxidation over time and maintaining initial performance for a long period.
Sockets use PTFE insulation and gold plating, offering high contact stability and excellent sound quality.

Ebony Tube Protectors

African ebony is used around the 2A3 bases. The high-quality, sharp appearance enhances the presence of the chassis.