Another "kinda-newbie" head scratcher

@lewm Thank you for your input. I mentioned earlier that my problem was similar but different than OP’s. Similar in that our problems involve a preamp issue.

After further investigation and probing I discovered that the high pitched sound or distortion is in fact audible through the left speaker’s tweeter but not the right speaker.

I have followed this stream of comments and advice given to OP and tried most of at this point, to no avail. At this point I wish my problem was the same as OP’s as he is up and running again. @audphile1 gave great advice that lessened the sound effect by relocating the unit but did not cure it. I will take his final advice which is to send the unit back to McIntosh for repair or replacement.

Thank you guys for your input and advice, I really appreciate it.

@ericrhodes1 

If you are playing scratched records you are shortening the life of your stylus and ruining your listening experience. Buy new or mint or VG+ (as a worst case scenario) condition records, wash them before playing and you will enjoy the listening experience a lot more. Get a good record brush and static removal gadget (there are many). Clean your stylus after playing each side
The other source of noise during playback is cartridge alignment. If your cartridge is not set up correctly it will exacerbate surface as well as groove noise. Also, stylus shape affects the cleanliness of playback as well. Special Line or Micro Line stylus will make better contact with the groove and greatly reduce surface noise compared to the elliptical stylus for example. Joys and pains of analog. 
 

@gjfalls sounds like the MP100 needs to go back for repairs. I’m sure McIntosh will address this issue promptly. 

I suppose you’ve already tried swapping tubes, R to L and L to R. If not, that’s a first step. If it results in the noise moving from one speaker to the other, then you can suppose the issue is related to L channel tubes. Etc.