I am also retired, and I just would like to quote friend of mine who asked me what I am doing. I told him that I am retired. He answered: You are not retired, you are re-tired, rolling along!
Anyhow, decided to try the 6AU6A tubes. A friend gave me a little piece of wire which I cut to size and inserted in the sockets as per picture. Changed the jumpers to EF95 setting and plugged in the tubes. (Used my stainless steel tweezers with good results.)
Did not know if these tubes would work for me, so I ordered the least expensive GE tubes that I could find, less than $3 each, including shipping. A few days later I got a pair in the mail. These were made by RCA and had the name Bogen on them. Manufacturing date 1964-37; both the same. Oh well, what do you expect for 99c each +shipping? (Bogen made mainly commercial tube amps in the late 50's and early 60's. The brand exists today making PA amplifiers.) The original factory was in NJ, but there is nothing left of the factories - it is today the site of the Bergen Mall. Same fate for Tung Sol - nothing left except urban blight in Newark, NJ. Why can't I find much of the history of these manufacturers?)
Burned in the tubes for around 30 hours. First impression: the heaters are so dull and hidden that I cannot tell if the tubes are on from where I am sitting. I have to touch them to know that they are on - they get somewhat hot but not burning hot.
Listening: First impression enormous sound stage - on some recording the sound emanates from outside the right and left speakers! With the present setup in my room I cannot move my listening chair back far enough to get a center image - it is as if I am listening to two halves of the recording. Have to work on getting the sound stage right.
Second impression: Extremely clean and detailed bass and low register. It is as if I brought home a refrigerator sized sub woofer instead of the 10" ones I have.
Third impression: The mid range is not the sweetest, and the top end too bright. I have turn down the treble on my receiver to counteract the excessive brightness.
In summary: Fantastic tubes! Now I am just waiting to compare to the Tektronix matched tubes that I ordered.....