"I'm more than beginning to suspect a curious "malfunction" in my processes if not hearing/interpertation."
Again, SPL meter would help establish if the effect is real/physical/measurable or not if in doubt. If it can be measured, then you know with confidence what you hear is for real and not an artifact of your hearing or how you listen.
IF nothing measures, then two options:
1) try an amp that is clearly better for the job
2) track down Mr. Freud and see if he is available. :^)