Made in USA
Sylvania JAN-6SN7GT Joint Army-Navy
Military Grade
Black Plate
Black Base
New in Original GVT Box
Amplitrex AT1000 Tested
Up for sale is a single (1 Pc) vintage NOS military-grade Sylvania JAN-6SN7GT dual triode vacuum tube, packaged in its original government (GVT) box. Made in the USA to rugged joint army-navy military standards, this highly sought-after audio tube features legendary black plates, a solid black base, and heavy-duty internal construction designed for supreme durability and low microphonics. Celebrated by audiophiles worldwide, vintage Sylvania 6SN7GT black plates deliver exceptional bass dynamics, an exceptionally lush midrange, and outstanding holographic imaging.
The tube has been tested on an Amplitrex AT1000 automated valve tester at nominal factory specs. Anode current (Ip) and Mutual Conductance (uMhos) measurements alongside percentage performance ratings relative to standard specs are detailed in the table below.
| Serial No. |
Triode Section |
Plate Current (Ip) |
Mutual Conductance (uMhos) |
| Ref Spec |
Result |
% Ip |
Ref Spec |
Result |
% uMhos |
| SR.NO. 1394001 |
T1 |
9.0 mA |
12.8 mA |
142% |
2600 uMhos |
3430 uMhos |
132% |
| T2 |
9.0 mA |
8.3 mA |
92% |
2600 uMhos |
2900 uMhos |
112% |