Up for sale is a strong matched pair (2 Pcs) of vintage NOS Tung-Sol 6SL7GT high-mu dual triode audio tubes, packed in white boxes. Manufactured in the USA, these iconic tubes feature premium black coated glass envelopes designed for optimal internal shielding and thermal dissipation, paired with a solid black base. Renowned across the audiophile community for their rich mid-range tone, low noise floor, and deep dynamic bass extension in high-end preamplifiers, phase inverters, and driver stages.

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