Up for sale is a matched pair (2 Pcs) of vintage NOS RCA 6SN7GTB dual triode vacuum tubes, packaged in white boxes. Manufactured in the USA, these tubes feature black plates, a compact coin base construction, and a top ring getter assembly. Famous for RCA’s signature rich tone, rich midrange, tight low-end authority, and exceptional detail retrieval in audio preamplifiers, driver stages, and line-level tube equipment.

As shown, both tubes have been thoroughly tested on an advanced Amplitrex AT1000 tube testing system in full fixed-bias mode, testing strong and closely matched across all sections. Plate current (Ip) and mutual conductance (Gm) measurements alongside percentage performance ratings relative to nominal factory specs are detailed in the table below.