Power Cables and Wall Sockets

One thing that I am curious about is if upgraded power cables will eliminate the issue of my lights dimming when listening at reasonable high volume.

I had that happen to me in an older home. Over the years the connections at the wall outlet can become loose. The simple fix was to shut off the circuit at the panel. After verifying the circuit was cold, I removed the plate and pulled the outlet out from the wall just far enough I could get a screwdriver on the screws and tightened them up again. A couple were barely finger tight! Once retightened, problem solved! You might try this simple and free fix.

Happy listening.

@retiredfarmer thanks for your encouragement. I love that you said that it was hard to believe the increase in resolution from addressing the power side of things.

I was thinking of simply upgrading my outlets to Hubble commercial, but I may think on this a bit longer. The idea of changing an electrical outlet and having a "stunning" effect on the sound gives me pause!

@imanitaural, just to be clear, I am absolutely recommending that you address your mains wiring and outlets as a matter of priority. If the wiring is the age it is, I would really consider running in a new line, ideally dedicated to the hi fi. The insulation on mains wiring can deteriorate with age and if your amp is drawing the kind of current that dimming lights implies, you will gain a worthwhile safety benefit as well as better sound from replacing the wiring.

As regards affordable power cords, I've had good results from the Audience Forte, auditioning it against the much more expensive cables in my own system. It delivered very respectable results for the money.

All you really need are good hospital grade outlets. Be choosy because some are better than others with regard to terminal grip and material and construction.

I used 10ga solid copper Romex. If your run is short, 12ga will work. 10 ga is very difficult to work with especially at the outlet. 

On average, my dedicated outlets consistently put out 2-4 volts more than the other house house outlets.

I won't lie. All this work and money made a relatively small difference. But, like many of us, I have a lot 'small differences' going on.

imaninatural

You have received a lot of good advice ,  but I'll still add my 2 cents worth .

Start with finding everything that is on the circuit that your system is on , then you should at least replace the outlet (s) that your system is on with a minimum of hospital grade ones , then open up every outlet , light switch and light fixture !! yes that's is a lot of work but I'll guess that there are loose wires somewhere .  As you inspect the outlets and switches you can decide if you want to spend the money on replacing them with HG ones ( I did ) .   

You could also do a quick test , take an extension cord of at least 12awg that is long enough to run your system to another outlet on another breaker circuit , just to see if the problem is your circuit or possibly even your system ( least likely ) .

If the problem of dimming light disappears then you can experiment with spending money power cords , more expensive outlets and even going to a dedicated line .

Good Luck