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

He won numerous awards for the A-08SSYamamoto Sound CraftHowever, the A-011SS is a model developed specifically for 2A3 vacuum tubes, further refined its design philosophy and high-quality sound technology. Even the medium-sized speaker, which was lacking in power with the 2W output of the A-08SS, can drive with confidence with this 4W output. Even with a medium-sized speaker, you can fully enjoy the rich midrange and sound field expression that is unique to 2A3.
The 2A3 is produced in large numbers all over the world, from vintage pipes to new and current products, and is also attractive because it is relatively easy to obtain. The A-011SS is designed to be used to replace most 2A3s without any complicated adjustments. No ham adjustment is required, allowing for a clear, quiet playback. It is truly a fitting thing to call it a "2A3 reference machine."
The 2A3's clarity, emotional midrange and powerful sound combine to create even more vivid music.

Vishay thin film resistors with precision, muddy sound

We use Vishay's Thin Film Resistor over a wide range of areas.
Compared to typical carbon/metal film resistance, the error is 0.1% and the temperature coefficient is orders of magnitude superior, at 10-25 ppm/°C.
Even with large amplitudes and transients of music signals, it suppresses fluctuations in resistance, achieving an accurate tone without turbidity and a high sense of tranquility (noise is about 1/10th of a typical metal coating).

SiC Schottky Diode + Independent Power Supply Circuit

An 80 rectifier tube is used to rectify the power source for the output stage, and the driver stage is rectified using an Infineon SiC Schottky diode as an independent power source.
A clean power supply without spike current increases the transparency and three-dimensionality of small signals, making localization and depth even clearer.

DC ignition + ultra-low impedance reflux

All 2A3/717A heaters are driven by DC ignition with double wave rectification.
The ultra-low loss Schottky diode reduces power supply impedance, achieving a speed of rising and a sense of energy.
The hum balancer, which causes deterioration in sound quality, is not used, and the circuit design reduces the hum.

Power/output transformer for high-bee cut cores

Both the power supply and output use Hi-B type cut cores.
The output transformer is custom-made 100 µm core material with PTFE (fluorine resin) insulation paper, achieving both wide band, low loss, and high linearity.
It depicts a tight low range, clear high range overtones, and detailed sound fields.

High S/N design with carefully selected parts

Both the type and power source systems are mainly composed of polypropylene film capacitors.
We minimize the use of electrolytic (chemical) capacitors, which are disadvantageous in terms of sound quality.
Resistance has carefully selected highly rated parts such as DALE metal clads and Vishay large capacity SMDs.

Silver-plated copper wire + fluororesin socket

The part wiring is made entirely of MIL-standard silver-plated copper wire (PTFE insulation), which suppresses oxidation over time and maintains initial performance for a long period.
The socket is made of PTFE insulation and gold plating, providing high-level contact stability and sound quality.

Ebony tube protector

African ebony is used around the base of the 2A3. The high-quality, manly design enhances the presence of the casing.