noise on the line

oops, just realized that Rex might be on a sailing trip 'off shore' the next few weeks. so if you reach out to him there might be a delayed response.

Thanks for the mention Mike and the link ditusa.  I have seen that link but forgot about it.

I do find there is a lot of noise on the power line.  My personal experience so far have shown me the following

Power cords make a sound.  I don't mess with them personally so I don't know if its better, worse or just different.  I don't see why shielding on a power cord matters.  I don't see RF noise entering the power cord and disturbing an amp., preamp, digital or really any other equipment.

Phono equipment can be severely impacted by RF from the air.  I see it all the time.  Shielding of cables can help.  Cables such as the  cable in the tone arm or the cable from the arm to the preamp.  Signal  cables.  Not the power cord.   Any signal cable from a phono system that gets near a power cable can be severely impacted.  So a shielded power cord may help to reduce induced power cord EMF noise to the phono signal cable.   The same goes for speaker cables.  Keep them clear of any power cable.  Consider what is in your wall.  Branch circuits radiate right through drywall.  Space is your friend.  Think 6 inches or more. 

Power line noise from the utility is very real.  Filters work.  I personally like a large wall mount isolation transformer.  Wall mount transformers work superbly on amplifiers.  I have heard no other filter do what a wall mount isolation transformer such as a Torus or a Equitech does on an amplifier.  Other isolation transformers are not the same.  Not unless you spent say $5000 to get a good one.

Other filters can be very effective on the front end equipment.  They all have a voice.  Even the wall mount.  I find the wall mount has less of a voice than others.  But that does not mean you wont like the voicing others bring better.  This is a personal choice. 

So, yes, you may hear night listening as an improvement over day.  I think this is an issue of noisy neighbors.  The link to noise generated by power lines would not change between day and night.  Arcing is arcing.  It does not care the time of day.  Well, let me back up.  Arcing is voltage and current.  If very little power is going through the utility lines at night, the arc is going to be less severe.  But its still there.   As far as your neighbor, crappy slide dimmers make all sorts of noise.  So do LED lights.  You should only have dimmers such as a Lutron Maestro in your own home.  If it has a slide, its no good.  If its has a soft start on off button and a digital scale at the side, it probably has superior filters stopping backfed noise into your own panel.  

I don't hear any difference between night and day with my Torus WM45.  I have measured a significant reduction in radio interference between a line feed by a Torus and direct to the wall.  The Torus is not a brick wall.  It  seems to shut down about 85% of noise through the power line.  Please note, this is noise measured from a meter such as an Entech.  A wall mount will do 0, as in nothing if your hearing radio out your speaker from your phono system.  The only way I have seen this issue resolved is moving the phono equipment to other locations in the room, or getting a phono preamp that is better at not letting the power supply modulate the RF into the signal to be amplified.  The noise in the power line has nothing to do with radio out the speaker when it comes to the phono system.

Noise on the power line is a veil and a loss of bass dynamics as well as some collapsing of the sound stage.  Noise on the power line affects all equipment.  You will notice the difference when it is reduced or removed.  

It’s more than just turning off the lights, it’s everything using electricity. Air conditioners, refrigerators, televisions as well as fluorescent lights, LED lights, can all dirty up your electric.

Yep, and your neighbors run all that stuff too.  Your sharing a transformer with maybe 6 people.  And utility transformers are not built to filter the same as a quality isolation transformer.  You have more blead through of all sorts of noise from up the line.  You want a good filter.

And, there is a crap load you can do with the wiring in your service, panels, branch and room that has a profound impact on equipment performance. 

I'm going to update my website with some images of how I polish contact surfaces now.  Just like the utility arcing, there is noise generated in your panel. It can be mitigated with material changes and hyper attention to detail.