@jea48
I had the monitors connected to my preamp through a set of XLR interconnects.
I had the monitors connected to my preamp through a set of XLR interconnects.
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:
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.
- ...
- 157 posts total
@jea48 "CORRECT". Also the AC hot and neutral polarity is correct. There is one thing you need to before you change out the duplex receptacle from the 15 to the 20 amp. I doubt the audio grade 20 amp duplex receptacle you bought has an auto ground clip feature. You can check it to see if it does though. On one end of the supporting backstrap, that supports the recept to the metal wall box, there will be a spring clip that applies pressure to the 6/32 x 1" machine screw that supports that end of the recept to the metal wall box. I found this You Tube video doing a quick search on the net to show you the auto ground clip. It also shows the bonding jumper, grounding pigtail, I will tell you about after you watch the video. https://www.youtube.com/watch?v=VuP5Mhvu9Y8 The guy did a good job for the most part with his presentation. I will pick apart one obvious mistake the guy made though, for anyone else that may watch the video. The wiring used to feed the box is NM-B cable, Romex is a trade name. Per NEC code the bare equipment ground wire must be bonded, connected, to the metal box. You will notice in the video the guy only connected it to the ground terminal on the receptacle. The receptacle cannot be used to make the bond, connection, to the metal box. james1969, If the 20 amp duplex receptacle you will be installing does not have the auto ground clip feature you will need to buy and install a green grounding pigtail wire. (Correct term is bonding jumper) Example: https://www.homedepot.com/p/Ideal-8-in-Grounding-Pigtail-12-AWG-Green-Stranded-Wire-with-10-Fork-10-... You can check around, surely you can find someone that sells in a smaller quantity. You will need to look inside the metal wall to make sure the box has a 10/32 tapped hole for the grounding pigtail to fasten. Some really old boxes does not have the 6/32 tapped hole. Hopefully yours does. If not post back. . NOTE: Just so you know.... Per NEC, and no doubt local city electrical code, you cannot install a 20 amp receptacle on a 15 amp branch circuit. Jim |
- 157 posts total