Well, I shared the same amount skepticism about these tubes, and then I received as a surprise, a pair of 12AX7 tubes. I can, with no doubt, recommend them. Not going into detail, they just sound right to me. I should add, that shortly before I received these tubes, I bought a pair of 'TJ music?' 6SN7 tubes, and was pleased with them as well. Very good detail, which is primarily what I like. The 12AX7 tubes have provided a cleaner bass.