I'd like to add something I've experienced. I've occasionally (on many different amps and guitars and rack components) found I was gettting very mild faint distortion at the ends of notes, when I either didn't think I should get it or hadn't noticed it before. What I found was the distortion was coming from poor connections somewhere in the system. (My basement can get humid). I used to use brass 1/4" phone plugs (long time ago) and after I discovered that they would get some surface corrosion and start adding distortion, I started treating them with DeOxit (I know I sound like a commercial, I've also recommended it for cleaning and preserving strings). Now, usually yearly, I'll clean my plugs and jacks with DeOxit, just to maintain the best connections. I also know any noise in the pots on my guitars wind up as faint distortion on top of the notes. My main guitar now has a noisy volume pot, before I play I work the volume control until there's no more crackling at all out of it. It should be replaced, but until working the pot fails to fix it, I'll go the lazy route. Anyway, when you think you should have a pristine clean sound and don't, check your connections. Output jack on the guitar, the plugs on any cords, the jacks they plug into. If nothing else, plug them in and out several times, that helps even if you're not going to use contact cleaner. If anyone else has experienced this, I'd be interested in hearing about it. If no one else has ever experienced this, then I've deluded myself thoroughly for decades. ;-}