I did something just like this back in 2000, as soon as I find the schematic I will post it.
But the output capacitors influence the sound, so no matter what you do, the output caps
are a significant part of the circuit. Mine lifted everything by 300V so no output caps.
Various versions of this have been around a long time.
sennheiser hev70 opamp and mosfet current source and mosfet drive, capacitor...