If you can build tube amps then it seems that is the direction to go. Make your own. Maybe look at https://www.diyaudio.com/ and google "DIY audio" to find sites with kits, or parts and circuits. Lots out there. Since you can build your own,, I bet you'll find it more satisfying and engaging. Being hands on, listening and tweaking as you go, you will get to know and hear all the shades of difference between tube types and circuit designs just as you have with guitar amps.
