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.
128x128james1969
No, my phone has no affect.  I wonder if it's because I'm on Verizon, and the offending tower may be a GSM tower?
I thought it was my interconnects.  I turned off everything except my amps, then I disconnected the interconnects, the noise disappears for a while...but reappeared.  Maybe my speaker cables are suspect too...
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james1969 OP286 posts11-16-2017 1:35pmI thought it was my interconnects.  I turned off everything except my amps, then I disconnected the interconnects, the noise disappears for a while...but reappeared.  Maybe my speaker cables are suspect too...

You need the RCA shorting plugs for the amps inputs.