I currently own a BRZHIFI A20 which I bought as an experiment. It is my first tube amp. I noticed it is VERY similair in design to the Reisong A10 PCB version. In fact I dare to say they are the exact same amps! Only differences being in terms of quality. Are they the same?
I want to experiment with upgrades to see what it can do. Replacing the caps with film ones should be easy. But what more can be done?