Several years ago, I acquired an Epiphone Genesis electric guitar. It was free, but needed repair. The neck had snapped, but the amazing people at Specimen Products did an even more amazing job restoring it for far less than what that guitar was worth. So I figured it was a sign that I need to learn to play. (Now the cats knocking over my guitar stand and snapping the neck a second time, that might have been a sign too….)
Being an electronics geek, and having an interest in retro technology, of course the only way to go would be a tube amp. And a friend moving out of town conveniently had a tube amp kit she built, but it didn’t work. She’d part with it for the sum of $20. Sold! The chassis was clearly homemade, but I figured that if I could get it to work, I could always rebuild the amp on a new chassis at a later date. And Pumping Station: One recently acquired a finger brake for bending sheet metal, which will be ideal.
First, about the circuit design. Most normal single-ended amps work by having a power transformer that takes 120V on the primary winding, and at least two secondary windings. One provides a low AC voltage to powers the tube heater filaments. The other steps the voltage up so it can be rectified into DC, which becomes the B+ voltage that the tubes use to amplify signals.
