I always wanted to build vacuum tube or valve amplifier. finally I made one hybrid amp. just combined both valve and solid state. For the preamp section I have used 12ax7(dual triode) and for the solid state I built opamp based power amp configured in unity gain..
This is the low power version and I’m sure I am going to build medium power amp delivers atleast 5-10watts to the speaker and no solid state 😀
Here is the picture of my construction:
Nature, Electronics & Robots 