A very simpel design, propably originating from some documents from either Dynaco a company that was making transformers for Dynaco. The design is very simpel and the use of a PCB makes things yet simpler. No funny components, no extreme transformers or tubes (no 12AX7!!!).
PCBs and kits can be bought for a few shillings or lire from eBay or AliExpress and propably a million other places.
Critisism? Well ... I dunno. Read somewhere that the design is crappy, but has that person tested the design?
I want to finish this one as it is a perfect simple and definitely non-exclusive project.