Electrical Noise, Thoughts?
 

I recently started hearing the hum coming from my preamp, DAC and streamer/server.

My system sits on a dedicated 20 amp circuit installed on a low use panel.

I tore down the system with power and interconnect to see if it’s related to a ground loop, no such luck. Also, pulled the Furutech outlet being paranoid, no issue properly hooked up and tight.

I came from a PS Audio P10, and changed to the Nordost QRT distribution system, as it did not limit my system.

There is no cable TV, and the dimmers are on a separate circuit and tested by power off, no issue.

Recently the electric company upgraded the meter and I just got off the phone with them, they indicated there has been a small amount of customers reporting issues of all sorts but in small numbers. The upgrade took less than 10 minutes to change the meter from analog to digital.

Across the street is a full remodel and the transformer is on the same pole were power goes into their home, not sure if something happened there.

Of course this is driving me crazy!

Any thoughts on the meter or the home across the street?

Are you sure that the hum is plaguing all sources? Have you checked to see if perhaps it is only the preamp, or only the DAC, that is the source of the hum?

Try putting the P10 back in your system to see if the hum goes away.

When I installed the PS Audio Noise harvesters.. It was clear the dimmer in the bedroom, on a separate circuit and all that, still was causing the Noise Harvesters to blink a lot.
Now if the dimmer is off, and the hum is the same.. it will not be the dimmer.
Often hum is a DC offset problem. And since you got a new meter.. it may be the problem. I do not know of there is a way to remove DC?
I am pretty sure DC cannot get through the PS Audio regenerator

Thanks for the response, and here are comments to your input:

Cleeds - hum is across the board, broke it all down, power cable and interconnect.
Higgens - P10 has long been sold.
Beet Farmer - Agree on comments about dimmers, and DC offset, P10 has long been sold

If it’s DC on the line, you might consider a PS Audio Humpbuster III.

https://www.psaudio.com/wp-content/u...II_-Manual.pdf

I’m sure Ivan can hook you up.

Ed.......Just a suggestion, but you might want to check that the main panel bond (the connection between the ground bar and the neutral bar) is tight. This bond is sometimes done with a screw through the neutral bar to a threaded hole in the panel enclosure. The screw is often green in color. The sub-panel you are using to feed your 20 amp dedicated circuit should not have a bond (the connection between the ground bar and the neutral bar) installed, but should have a ground wire from the sub-panel ground bar back to the main panel ground bar. Bonding the neutral and ground should only happen at the first point of disconnect, typically the panel with your main breaker. Also, check that the ground and neutral wires that feed your sub-panel are tight on both ends. Finally, check that your main ground connection in your service panel is tight at the panel and the ground rod outside. In addition, you may want to look at the utility transformer to be certain there is a ground installed between the transformer neutral and a ground rod at the base of the pole. Don't mess with the utility power connection at the ground rod, just check to be certain it is in place and secure.

Thank you for the recommendation, and yes Ivan is a go to source.

Dan, thanks for spelling this out, I talked to an electrician friend today and he recommended much of what you indicated plus wants to put a second grounding rod to the sub panel.

Puget Power is coming by tomorrow at 0800 to look at their new digital meter recently installed which I’m hoping is the problem, one way or another this problem has to go bye-bye.

Hmmmm, I am not sure that meets code. Dan will know for sure. My understanding - and it's the code where I live - is that all grounding rods must be bonded together and connected in the main service panel only, along with the neutral. The ground on a subpanel must go to the main service panel, where it is bonded together with the other grounds. You cannot install grounding rods separately from those connected to the main service panel. Again, that's the code where I live.

One problem I've heard about from a friend who is a master electrician: he has seen utilities install new meters improperly, where they are not firmly seated in the meter pan. That can cause all sorts of issues (including fire) and I'd guess your utility will check that.

Good luck to you and please report back to us on the outcome.