4 Tung-Sol 6K6 6K6GT Vacuum Tubes Black Glass Lot Of Four NOS-Testing 25BK5 This GE 11BT11 tube tested

This GE 11BT11 tube tested to spec on our Paul Hart-calibrated TV7/U

I played this tube this morning it in my Bottlehead Crack headphone amp with Sennheiser SD 580s and it sounded excellent

IN NEARLY 9000 SALES IN BOTH OF OUR ETSY STORES

The Bottlehead calls for a 12AU7 which is a pretty-different tube

Transconductance measured 41/49 for Tube One and 44/44 for Tube Two where minimum (65%) is 32/32 and 100% is 49/49

4 Tung-Sol 6K6 6K6GT Vacuum Tubes Black Glass Lot Of Four NOS-Testing 25BK5 This GE 11BT11 tube testedThis new old stock testing lot of six Tung Sol black glass 6K6GT tubes were tested on our Maxi Matcher 2 with 325 volts on the plates and a bias of 36 volts for shorts, gas, plate current and transconductance. There were no shorts or gas and they measured as follows (from left to right, top to bottom): Tube One: 31. 8 milliamps' plate current 2170 micromhos; Tube Two: 35. 1 1980; Tube Three: 40 2120 and Tube Four: 42. 1 2260. New nominal