It's nice to see this here -- as Ellen Fullman said, instrument building is composition.
Another very impressive thing they did was never stop.
I continued with experiments using vacuum tubes more so into this century although I slacked off without a bench in recent years due to serious losses from natural disasters as they have come along.
I really had my old vintage gear in shape and some new developments which sounded excessively tubular, and it had been a good reason to break out the old guitar even if just to test the amps numerous times per session as I was auditioning components and circuit possibilities. When I was at the bench I would spend about equal time soldering and playing.
I was playing the same old stuff so I could reference the underlying differences in the circuits, I'm not a songwriter to begin with and I definitely was playing worse than ever, but with just a few hours of soldering I could get better tone than I ever had in my life.
I needed all the help I could get anyway at that point and I guess I did have nothing to be ashamed of, but it was easy to admit that I was getting more progress out of spending two hours soldering than practicing music.
Ended up with the amps as my instruments and the guitar as the equipment, and did some fun gigs with talented musicians for a while there.
I never wanted to stop either.