My Pass dealer told me to do so (right into the wall), as recommended by Pass. Sure enough, all surge protectors or AC filters I tried made my X350 sound compressed. I have discovered the same is true with my Edge NL12, which is now also right into the wall. (My source components, however, benefitted from being plugged into my Hydra 8.)
I have never had a problem in my house with this arrangement.
I have never had a problem in my house with this arrangement.