high frequency intermittent noise


I have a noise issue that is intermittent.  Here is what the noise sounds like:

https://clyp.it/4b233bmm

Here is what I know so far:
  • The sound affects all components and is compounded if all components are turned on.  I have turned off my preamp, phono preamp, leaving just my mono blocks on, and the noise still appears.
  • I have turned off everything and unplugged everything in the house including my dimmer switch, and the noise still appears.
  • I have a pair of pro-audio monitors, self powered with class AB amps, and when I plug those into the same outlet, I hear the same noise coming through the pro-audio monitor.  So this rules out my big system.
  • The noise is primarily during the day and goes into the evenings, weekends too, early mornings it does not appear.
  • I live in a pre-war mid-rise building.  I have no ground, I'm using a Nordost QKore grounding system.  This did reduce the noise floor quite a bit, but has no affect on this intermittent noise.
  • I have a cell phone tower directly across the street from my building in Manhattan.
  • Looking at a real time analyzer, I see peak at 2kHz when the noise appears.
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Showing 4 responses by randy-11

if you turned off all wifi routers, then try turning off the cell phone tower

or last chance, try a different circuit - wall outlet
cell traffic is also likely very low in the early am when he rarely hears the noise

BTW, are your interconnects single-ended RCA type?  if so, can you switch to balanced or do the components only support SE?
unless... the cell tower is somehow causing the lower freq. noise - maybe drawing on a power supply or something
if you are in NYC, you do what some sports car owners do - have a site outside the city where it is kept and subway out to it for a drive (or in your case, a listen)

a place in the Catskills could contain your most sensitive equipment and something else used in the city