Sylvania Perfect 0% Matched Pair (2) JAN-CHS-6SN7WGT WGTA tNOS AT1000 TESTED Balanced! PI Vacuum Tubes 3-hole Bad Boy rugged military dual triode 1951-1957

This listing is for a Matched (10% in GM) Pair (2) of Sylvania-made JAN-CHS-6SN7WGT WGTA dual triode vacuum tubes in the straight-walled glass tube shape. They have a brown micanol octal base, 3-hole inward-facing T plate, and bottom square getter.

This SKU includes all Syl heavy top-getter flashing brown-base military 6SN7 from 1951 to 1956. All have inward-facing T-plates. Most are WGTA, but some from 1952-5 are WGT.

These tubes have been selected to match one another for optimal performance! Matching is based on plate current for power tubes, voltage drop for rectifiers, and transconductance (Gm) for other tubes. Perfect match in GM for all four sections! Unbelievable!

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 tubes have 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 1951 RCA, Western Electric, Sylvania, GE, and/or Tung-Sol datasheet specifications for new tubes of this type. The tubes 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 tubes 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 tubes 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 tubes you will receive! SKU 6SN7-312WBadAmp. 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.]