Help troubleshooting McCormack separates?

I've been trying to lick a persistent electrical-souding buzz that comes and goes in my rig, and recently downloaded Ethan Winer's test tones from the RealTraps website to see how much of the problem was real, and how much of it was psychosis.

When playing the 300Hz sine wave I was able to hear a not unpleasant "tubular bells" sort of note, accented by a much drier, less pleasant overtone about a half-step below the main note in pitch -- rather like the sound that animation studios use to simulate a housefly. If I raised the volume, both the tubular-bell note and the overtone would decrease in pitch, and if I lowered the volume they would both increase in pitch (I know that sounds crazy, but I replicated the effect several times).

Also, the overtone briefly got louder if I adjusted the volume in either direction, then returned to its previous volume, relative to the main tone. The effect occurred equally when using my Arcam CD-player or my Oppo DVD player, to play the tone.

My question for the group: is this enough evidence for me to conclude that I'm facing a service issue with the McCormack stuff, or could all of these results be the combined effect of how the test-cd was burned, room interactions, dirty power (specifically, un-grounded outlets), normal performance of the test tones, and unadulterated psychosis, and/or stupidity on the part of the operator?