Tung-Sol 6SN7GTB tNOS AT1000 TESTED Balanced! PI Vacuum Tube T8 rare medium glass dual triode 1962

This listing is for one (1) Tung Sol-made 6SN7GTB dual triode vacuum tube in the straight-walled glass tube shape. It has a black bakelite octal base, angled black T plate, and top halo getter.

This variant was only made with date code 322NH3 as far as we can tell! We just got one more in stock! The civilian 6SN7 tubes from Tung Sol have been given "type codes" by Sound by Doc as follows: T1 (pre 1951) GT, medium glass, bottom square getter, parallel ribbed black flat plates with 2 support rods. T2 (1950) rare square mica mouse ears, inward-facing T plates. T3 (1950-2) Mouse ears black T plate. T4 (1952-3) Mouse ears grey T plate. T5 (1953-5) inward-facing grey T plates. T6 (1956) Just like Sylvania "Tall Boy," 2-hole inward-facing black plates. T7 (1956-61) top getter tall glass angled black T plates. T8 (1962) rare medium glass. T9 (1962-6) short glass.

This tube has been tested to be perfectly balanced in transconductance (Gm) between the two sections. It is appropriate for phase-inverter positions and other demanding roles.

Your tube has been fully tested on a computer-regulated, USA-made Amplitrex AT1000 on Fixed Bias setting with like new, NOS results (tNOS). Here's what that means: to qualify for this listing, several stringent conditions must be met: The transconductance for each section must measure between 2080 uMhos and 3120 uMhos, consistent with original 1962 RCA, Western Electric, Sylvania, GE, and/or Tung-Sol datasheet specifications for new tubes of this type. The tube must also show no shorts, show a gas current less than 0.9 mA, and a heater-to-cathode leakage of less than 10 microamps (10 uA). The tube might have mechanical wear or have the label rubbed off - these are very old! Used-testing tubes are available in a separate listing at a significant discount. Every tNOS or Used Good tube you receive from Sound By Doc is guaranteed against failure for 60 days after purchase, an industry extreme!

These photos are not stock photos. You are looking at the actual tube you will receive. If a box or boxes are in the photos, you will get them. If test results appear in the photos, look close, because those are the test results of the tube you will receive! SKU 6SN7-322T8PI. Please note that matching is nearly always possible for us from stock that is inventoried but not yet listed. If you need a matched pair or quad etc., please use the make-an-offer feature through Reverb. Matching requires an extra burst of effort, so please add $5 per tube to your offer for 10% matching and $10 per tube for 4% matching. [Matching is based on plate current for power tubes, voltage drop for rectifiers, and GM for all other tubes. If you also require the label or internals to match, please specify that in your offer.]