Astro Electronic Planning AST-6SN7 Vacuum Tube Stereo PP Power Amplifier

Astro Denshi Kikaku, a manufacturer of vacuum tube amplifiers, is developing a new series of amplifiers that are lighter and easier to handle without sacrificing sound quality by reducing the width and size of the amplifiers from its previous lineup of full-size, bulky, and heavy amplifiers.

The AST-6SN7 push-pull style power amplifier is available in two chassis options: stainless steel or aluminum. The original internal component mounting fittings are produced and machined into a two-stage structure to suppress resonance and improve sound quality. The anodized aluminum front panel, made of 10mm-thick 52S aluminum alloy, and the knobs for the VR also create a fascinating appearance that accentuates the shiny vacuum tubes.

The output tubes are equipped with a self-bias function, so they can be easily replaced with compatible bulbs for your enjoyment. The self-bias capacitor used in the AST-6SN7 has a large capacitance of 470 microns, compared to the 100 microns or so used in most amplifiers in the same price range.This allows a margin of current capacitance, which results in performance comparable to a fixed bias.This allows the sound to be well represented even when the volume is turned down. Since it has independent left and right volume controls, you can easily enjoy high-quality tube music by connecting it directly to a CD player, smartphone, tablet, etc. without a preamplifier.

The transformer uses an original transformer that keeps the price low while delivering sound quality as good as that of higher grade transformers. The legs are made of a combination of aluminum and rubber materials. Circuit parts and chassis mounting parts are also made of carefully selected materials to pursue high sound quality,The two-stage internal structure prevents resonance from both inside and outside, contributing to a high sound quality with transparency and no distortion.