Symptoms of UN-CLEAN power

Two caveats prior to responding. I really don’t know how clean my power is out of the wall compared to your situation. We just built and moved into our house. So, the power distribution is new. Our neighborhood was farm/ranch land until the last few years. We have a neighbor that raises camels. Secondly, your equipment throws noise back into the power line, so not all noise comes from your house/utilities power distribution.

I made a major change in power to my system, pretty much all in one go. I was floored at the difference, but to quantify the difference is a challenge. The presentation was more detailed, with more air, silence between notes and better imaging. Everything was just more musical. Listening was less tiring.

For me, power upgrades involved adding a Shunyata plug, Everest conditioner and a Sigma power cord to my integrated amplifier. I had a three pack of Venom and some old power cords… so my power upgrade wasn’t really in one step. Later I added Venom NR to my subwoofers and replaced the remaining power cables with Sigma NR. I purchased items with a sixty day return privilege and my salesperson let me just trade up without any loss of funds, even after the sixty days. So, more money spent on power than any other one component. I intend to add a dedicated circuit, but my current power distribution is from a garage on the opposite side of the house. My listening room is over the second garage, so will need a long run to second panel.

I believe that addressing power is the single biggest improvement to my system. Other changes, balanced analog interconnects and speaker cable were more nuanced improvements. Digital cabling (AES/EBU and Ethernet) improvements were the second largest cabling improvement seen on the digital side. Room treatment is probably up there with power as an important component of good musical reproduction.

Bigtwin, you already tried to mess up the tread twice. How about letting others answer the question for the OP.

For me, system noisy one day and quiet on others. Especially with tubes.

Having just went through a power upgrade, I can provide my experience. I went from an old electrical panel and one 15amp line to having a new panel and three dedicated 20amp 12gauge Romex lines, good Siemens breakers, each placed as far away as possible, better grounding, and run to quality Audioquest outlets. I kept it as simple as possible after doing a lot of research prior.

My system didn't sound bad before, but it went up several levels after the upgrade. Noise floor dropped significantly, bass strength and definition improved, more detail comes through, and the whole system sounds more 'effortless'. It made a bigger difference than many components I've added and was significantly cheaper.

Power cable influences on equipment has to do with a) less contact resistance b) less rfi and emi pick-up, and transfer to the component c) less cross-contamination from components on nearby other components and cables d) less voltage drop e) less (lower) leakage currents and parasitic capacitance between components.f) quicker rise times/faster current draw. 

But, if the incoming electricity is dirty the effect will be reduced offcourse,  

Sometimes changing one power cable can have an effect on other equipment in your system.You only hear the endresult. A lot of people have heard the change a good power cable can bring to your system. Who I am to judge? If you don't hear it, be happy and listen to some good music.

Love to hear other peoples experiences. 'Facts', 'Engineering' and 'Measurments'. can be discussed in Tech Talk.