There are some details that I can't disclose such as how to control the MOSFET at high switching freq so it won't burn (that's why we don't see 700kHz class D amp other than Nuprime, it is very hard to do). Also how to control the transistors.
I think I can disclose that the first transistor is JFET

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Note that in the photo, the transistors on IDA-8 are implemented as a "module" (that's the big flat silver metal looking thing) but on Evo One, the input stage is very large, much more than IDA-8, so they are all mounted on the PCB.