Astro
TO-6550SFC Vacuum Tube Single Power Amplifier

Astro Denshi Kikaku, a well-known brand of high-end vacuum tube amplifier manufacturing, has introduced a mid-range series. Astro Denshi Kikaku is a manufacturer that does not compromise on the beautiful appearance, abundant information, and pure sound of its products, which are carefully crafted one by one by skilled workers using carefully selected materials. Since Astro Denshi Kikaku is such a manufacturer, the internal parts of the amplifiers are carefully selected and manufactured by the same skilled craftsmen as the high-end models, resulting in amplifiers that play music with a high quality sound similar to the high-end models.
TO-6550sFC is a single type power amplifier, and its high purity sound quality is firmly in the vein of the high-end models, Astro Electronics' amplifiers.
The sound is superb, and while expressing the delicate and detailed sound of a single amplifier, it also has the nostalgia of being able to handle any genre of music without a hitch.
The output tube is equipped with a self-bias function, so it can be easily replaced with a compatible bulb for enjoyment. The self-bias capacitor used by Astro Denshi Kikaku is an order of magnitude larger than the 200~300 micro capacitors used by most other manufacturers, at 8000 micro. This allows the sound to be expressed well even when the volume is turned down.
The independent left and right volume controls allow for direct connection of a CD player, etc., and fine volume adjustment for enjoyment.

The chassis of the TO series is made of 2mm-thick aluminum, anodized in champagne cold silver. The TO series chassis is made of 2mm-thick aluminum material anodized in champagne cold or silver color, and 2mm-thick 52S alloy aluminum material is used for the component mounting material. Insulators are also made of a combination of aluminum and rubber materials. Circuit components and chassis mounting parts are also carefully selected for high sound quality. The internal structure is two-stage to achieve even higher sound quality.

Vacuum Tubes Used	6550 x2, 12AX7 x2, 6CW5 x2, 5AR4 x4
Transformers used	PT-160 x1, HC-507 x2, L-C-1-200 x1
Outputs	7W +7W self-bias
Frequency Response	10Hz~50kHz
Residual Noise	Less than 1mmV
Input impedance	100kΩ
Size	W390 x H155 x D300mm
Weight	11.8kg