Those magical days when the HVAC is off

A couple months ago,,,,,plugged vacuum into kitchen wall outlet.  Dead outlet with no warning.  2 plugs on that wall both show dead.  Original 30 year old contractor grade,, so I replace with commercial grade.  Still dead.  One plug is end of circuit and the other feeds that one, and is fed (shows hot), and a second line out that goes ?   Isolating with breakers shows those plugs are part of adjoining bedroom circuit which tests out fine.  From the basement view it appeared kitchen fed bedroom.  After a week of mulling this over, I called a commercial electrician friend to look at it.  Didn’t make sense to him either.  He looked at the breaker box which looked superficially looked fine.  While gently probing neutral bar with a wooden dowel we saw very fine arcing around connections.  He recommended residential electrician…soon.   Hang in there, this story goes somewhere.   All bedroom plugs tested fine, but gotta start somewhere.  I removed the cover off of plug that appeared to be connected to kitchen.  Ok ,, bedroom feeds kitchen.  Neutral wire from kitchen still attached, but scorched, insulation gone, with the metal on the plug scorched.  That plug still functioning and tested good.  Replace that plug and incoming neutral wire.  That was that.  But,, that arcing neutral bar in breaker box.  Yup, very fine static like arcing still there.  I threw the main breaker and began to retighten all the screws on the neutral bar.  Many needed 1/4 to 1/2 turn to snug down.  No more arcing.  Nice.   So finally here’s the payoff.  The next day I resume my daily music ritual.  The improvement in audio was amazing.  Bigger cleaner wider, and especially airy.  Like upgraded equipment.  Weeks later, it’s still there. The wiring is the only thing in the house that changed.  

After reading through the comments here, I have some work to do.  My no HVAC baseline noise level, C weighted, is ~ 40 db!  I can't avoid the white noise of HVAC on, as there is are two ducts and one return in the room, plus the system is in an adjacent room.  Like many of you, I just try to avoid listening when it's running.  But getting another 10 db of quiet would be nice......

My problem is with the darn fridge running, seems noisier than most. I could turn it off, but then the beer would get cold.

My whole apartment is on a single, 20A breaker.  When I added a Ametek Powervar 8.3 my audio was way cleaner, and the background was black (silent).  It did not make my music clinical, which I've heard people complain about with some "audiophile" power conditioners.  My Ametek unit is a medical grade power conditioner, which is meant for protecting the life and longevity of electronic devices, which I feel more comfortable with.