Found this circuit the other day and was reminded of our common emitter output discussions for a +30 dBu output. https://proaudiodesignforum.com/forum/p ... t=50#p6664
![Image](https://proaudiodesignforum.com/images/png/ADI_High_Voltage_Boosted_Rail_Rail_Output_Composite_Op_Amp.png)
"High Voltage Boosted Rail to Rail Output Composite Op Amp," Jung, Op Amp Applications Handbook.
The above approach is a little different from our 2013 discussion in that it has thermal feedback and that the output stage is common emitter formed by a current mirror.