ASTRO AST-5881sSTK Vacuum Tube Stereo Single Power Amplifier

Tube amplifier manufacturer Astro Electronics has created a new series for beginners in tube audio. By narrowing the width and reducing the size of the amplifier, it is finished in a light and easy-to-handle amplifier. AST's STK series uses the company's first original internal board to simplify manufacturing and reduce production costs and production time.

Astro Electronics' original board is designed with thicker wiring than ordinary boards, contributing to the amount of information and sound quality. In addition, the transformer is the company's original design transformer, which is not inferior to the high-quality Hashimoto transformer, and has succeeded in keeping the price down without sacrificing sound quality. By carefully crafting each tube amplifier one by one, it is finished in expressive and powerful sound quality that will satisfy not only beginners but also enthusiasts.

There are two inputs, and you can enjoy full-fledged tube sound by directly connecting a music player such as a CD without going through a preamplifier. In addition, by installing an LED in the tube insertion part, you can enjoy a new visual effect of a tube amplifier that has never been seen before.

Tube amplifiers must be adjusted to stabilize the operating point (bias point) in order to optimally operate the tubes inside the amplifier at a specific voltage or current. The AST-5881sSTK has a self-bias function that automatically adjusts the troublesome bias, so you can replace compatible vacuum tubes and enjoy the difference in sound quality of each tube.

The self-biased capacitor used is a capacitor with a capacitance of 470 micro, compared to the capacitor used by general amplifiers in the same price range of 100 ~ 200 micro. As a result, while a general amplifier cannot express the sound properly when the volume is low, the sound is expressed firmly even when the volume is turned down. Since the left and right sides are independent volume control, you can finely adjust the volume, and you can easily enjoy high-quality music played by vacuum tubes.

The input terminals are high-grade gold-plated terminals, and the speaker terminals are machined aluminum plated terminals that are compatible with various speaker terminals, and it is a full-fledged model that supports speakers from 4 Ω to 8 Ω.