Matched Pair Sovtek EL84/6BQ5. Tube is allowed to heat and then gently. Made in 1999. One has no date. This tester is set to factory specs. Tested for transconductance with B&K 747. Life test good.
2x Tungsram 6AQ5 (= EL90 6005 N727) 1950s Black Plate, Flat Top, Fat Getter, Matched. For sale are 2x pieces of Tungsram 6AQ5/EL90 power tubes. These are the very early black plate, fat getter variant, with flat-top bulbs.