Yamamoto Sound Craft
"2A3" A-011 power amplifier

The A-011 is the simplest and highest quality system with a dual input volume, allowing you to connect a CD player directly to the A-011. When a CD player is connected to the A-011, the sound of the CD is reproduced through only two vacuum tubes.

The 717A driver tube and the "80" rectifier tube are used to improve the sound quality.

The CD player can be used with an ordinary preamplifier to control the input level, and an analog equalizer amp or other input devices can also be connected if the gain is slightly higher than that of the CD player.
The heater circuit of the 717A and 2A3 tubes uses double-wave rectification DC ignition to minimize noise, and the rectifier uses ultra-low-loss, high-capacity Schottky diodes manufactured by International Rectifier of the U.S. The A-011 has an energetic and powerful sound due to its low impedance. The A-011 has an energetic and powerful sound due to its low impedance.
A toroidal power transformer with excellent regulation and a high-beam type cut-core output transformer are used to achieve excellent sound.
Most of the capacitors used in the A-011, including the power supply, are carefully selected specially made film capacitors, minimizing the use of chemical capacitors, which are inferior in sound quality. Also, the resistors are carefully selected from high sound quality parts such as DALE wire wound resistors, metal clad resistors, and large capacity surface mount resistors. The speaker terminals are 8-ohm output terminals only, but there is no problem using 4-ohm or 16-ohm speakers. However, in either case, the maximum output power will be reduced; a maximum output power of 8W will be reduced to about 4-6W.

Type	2A3 Single Stereo Power Amplifier
Tubes used	2A3 (not included, or RCA2A3 included) 2 tubes, 717A 2 tubes, 80 1 tube
Maximum output	4W+4W
Frequency Response	20-30kHz (at 1W output)
Input Sensitivity	4W output at 0.4V input
Gain	24.5dB
Input Volume	100kΩ dual A-type volume
Input impedance	100k ohms
Size	400(W)294(D)204(H)mm
Weight	14.3kg