Up for sale is a matched pair (2 pieces) of prime vintage NOS Sylvania JAN 6SN7GT dual triode vacuum tubes, complete in their original GVT boxes. Manufactured in the USA to Joint Army-Navy (JAN) military standards, these tubes feature legendary black plates, a solid black base, and exceptionally sturdy internal construction. Sylvania’s classic 6SN7GT production is renowned among audiophiles for its holographic soundstaging, extended high-frequency detail, rich midrange density, and dynamic impact in high-end preamplifiers, driver stages, and integrated amplifiers.

Both tubes have been tested on an Amplitrex AT1000 automated valve tester at standard reference settings. Plate current (Ip) and transconductance (uMhos) measurements alongside percentage performance ratings relative to standard specs are detailed in the table below.