Tubelab SSE prototype fired up. With the right voltage and bias you can run all these tubes in Triode or Ultra-Linear with CFB if required - 6V6GT, 6F6G, 6P6S, 6P3S /-e, 807 (Top-cap anode), EL34, 6L6GC etc etc...
The amps been running ~ 30hrs and I've tried 6P6S /3S and 807s so far. With B+ @360v and biased to around 50ma, the 6P3S sound the best. The contraption on the right (toggle switches) adjust the bias current. The white toggle on top of the mains trafo, switch between 275 and 300v secondaries. The red toggle in front switches between tube and SS rectifiers. I needed the flexibility to allow different secondary voltages between 290v (5V4G) and 360v (SS).
Simple build and incredible flexibility. More to come.