I’ve never built a headphone amp before. Can I build a PPA?
The PPA is not a good choice for your first DIY amp project. You may succeed without any problems, but if it doesn’t work at first, you’ll be totally lost. The parts for a PPA are expensive enough that you’ll want to be reasonably confident that you can troubleshoot the amp if it doesn’t work when you turn it on for the first time. I recommend that new DIYers first read my article Getting Started in Audio DIY, and then either build a CMoy Pocket Amp or a PIMETA to get some basic skills before proceeding to the PPA.