Sorry for refloating this thread.
I'm listening to my "SquareWave KG latest version" in SE configuration. (Thanks Dr. Gilmore)
It works great and is very simple to assemble. I have regulated the BIAS @ 120mA without problems and could even raise it much more.
I have used a 100K resistor to make the servo act as fast as possible and from the beginning the offset is 0 Vdc so I don't need wait for listening music. I matched all the transistors as best as possible but with the MJE200 and MJE201 it was impossible to find an identical pair. 🙄
The next step is to install it in a box but I'm hesitating, Is it worth making a balanced version? Is there much difference between the SE vs. Balanced version?
I have enough material and pcb´s to do this without problems but if this does not make sense, I'll leave it in SE configuration.