2. tech-talk
  3. 132315-8612

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.
128x128Ag insider logo xs@2xjames1969
james1969's avatar
Ag insider logo xs@2x
james1969 OP
347 posts
 
I just went looking for my pro-audio monitors and just realized they are downstairs in storage.  I will dig them out if the Furman P-2400 IT has no affect.  I will be receiving the unit today.

If this noise is coming from the cell tower, I don't think there will be much I can do about it.

@randy-11

My Interconnects are single-ended RCA only.  I cannot switch to balanced because my system does not support it.  I can run balanced from my preamp to amps, but I do not have any XLR interconnects that long.
james1969's avatar
Ag insider logo xs@2x
james1969 OP
347 posts
 
@jea48 

I had the monitors connected to my preamp through a set of XLR interconnects.
james1969's avatar
Ag insider logo xs@2x
james1969 OP
347 posts
 
@jea48

I plugged in the socket tester and got two double orange lights indicating CORRECT. So I do have a ground?
toddverrone's avatar
toddverrone
840 posts
 
No idea. Doesn't it say on the tester? Correct sounds to me like the polarity is correct (live wire to the narrow slot, neutral to the wide). Didn't that thing come with instructions? 😜
james1969's avatar
Ag insider logo xs@2x
james1969 OP
347 posts
 
@toddverrone  

Make me go and dig up the instructions..🤓  CORRECT is good all the way around, so I do have a ground.
More to discover