For Gm, 1650 is the 60% reject point. For reference we used a Military TV-10 D/U tester.The item "6SN7GTA RCA Audio Receiver Pre-Amplifier Vacuum Tubes Tested Pair" is in sale since Tuesday, December 8, 2020. This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Parts & Accessories\Vintage Tubes & Tube Sockets". The seller is "chukv" and is located in Westwood, Massachusetts. This item can be shipped worldwide.