Nope, can't say I'm getting that sensation on my ES1sl.
I do get 'distortion' or 'crackling' during dynamic passages when played thru the BPT. It's so clean and clear that everything is heard. It doesn't happen when plugged inot the wall, but then again, it's not quite a s clear overall to maybe know.
The one time I thought it was getting fuzzy...I stopped drinking my favorite sake.
Is yours plugged in any conditioner? Play it with and without and see. The little wonder is so good, it may be picking up something in your audio chain you didn't ever notice before. Ain't that damn remarkable for your $280?
The symptom you're describing seems to be differnt than mine...I am not aware of it happening here. Mine is plugged in and playing 24/7, as well.