I have lots of 12AX7 and 12AU7 pull-outs. And I need to test them. While building some testing gear, I decided to add one more tube and transform it to tube amplifier. Why it is “second tube amp”? Because, about 20 years ago I already almost build my first tube amp.
This is photo of tube amp:
There are three tubes in amp. That fourth tube is just placed. Tubes are: 12AX7 (inserted 12AU7 too- it is working, but more quietly), 6ÐŸ14ÐŸ-Ð•Ð’ (6BQ5, 7189A) and VR150. VR150 is 150V “zener”, it is stabilising voltage for preamp.
Here you can see super-duper high-end guts of amp:
Everything done from scrap components. I used my beloved japan electronics from 1966. Only output transformer is used from some old Soviet TV
Here tubes glow in the dark:
My photo camera didn’t catch focus in the dark.