I have only one on a board right noe, listening in mono for a lot of hours as I've made changes and tried many combinations.
I ready to build the two final iterations and call myself have.
It is dynamic, balls with good solid base, midrange and extended highs.
Pretty much check all the boxes I am looking for.
That last experiment was a shunt regulator on the driver type power supply.
Nice little improvent.
Sounds great, ive been using a borrowed diy 300b set for the last two weeks and its nice but its not got great bass and not that good in highs either, the other amp i have had recently is a quad 2 and thats sort of the opposite but not quite what im looking for, fingers crossed for this PP2a3