While there is no difference between flac and wav and I cannot hear a difference no matter how hard I try, I can tell you from my experience some flac files 24/96 and 24/192 give me listening fatigue. For the heck of it, I converted them to wave and that solved the problem for me. All DACs convert whatever format into PCM; I think the process of unpacking the flac files prior to that conversion has some kind of an effect.
If you want to convert to wave, dBpoweramp can do that directly to your flac files without having to re-rip. It even has a batch converter to do them all at once.
If you want to convert to wave, dBpoweramp can do that directly to your flac files without having to re-rip. It even has a batch converter to do them all at once.