Power Cables and Wall Sockets

@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

@clearthinker … “Like many others you say the last six feet of passive cable can make a big difference.  How?”

Like a lot of things in audio… my brain says it shouldn’t matter and when I make a change the sound difference is quite striking. So experience says with absolute certainty, it does.

I have read a lot about why. I remember there is a video… I think by the founder of Shunyata explaining how to look at power… not as hose from the generator but as a tap from a lake. I’ve read quit a bit… honestly I just am not that interested to know. I am sure lots of folks here can point to references.

My dealer dropped an AudioQuest Variable Power cord (~$1.5K) the other day. I replaced my Cardas Clear Beyond with it. Wow… a startling difference… quieter background improved details without any loss of warmth. This isn’t the one made for power amps… damn… looks like I am going to be buying a $5K power cord.

Thanks @ghdprentice 

Like many others I am inclined to put even quite large perceived sound differences down to subjective hearing and listening issues, mood swings and expectation bias when they are engendered by changes of passive components like power cable, fuses, cable lifters and the like.  I am made more sceptical by the fact that such changes invariably are percieved to improve the listening experience rather than diminish it.  Not like a virus mutation at all, which is random and just as likely to ameliorate the effects of the virus than worsen them or, perhaps, to ameliorate some and worsen others.

But please let me enquire more into your experiences if I may. I am guessing most of your positive perceptions arise on changing the power cord of electronic components such as CD players, DA converters and amplifiers?

Some say they have perceived positive changes on switching power cords to an LP turntable.  Have you?

Or power cord to an electrostatic speaker?  My Martin Logan CLX Anniversaries came with very exotic expensive lookin cables - quite long too, about 10 feet,  Am I getting value for what I paid for those?   Electrostatics don't pull down much current, especially once the initial charge is completed and they are just being 'topped up'.  Thinking about that, could the electricity supplied by the exotic cable to power up the speaker initially continue to improve the sound afterwards?  But that situation is analogous to that in a big monobloc.  The amp draws power on switch on that is stored in a huge capacitor.  Once stored can it really retain the enhanced character that it acquired from the 'high-end' supply cord?

I have a pair of old Audiostatic speakers that are powered by fixed manufacturer supplied cords not much heavier than bellwire.  But the speakers sound pretty good.  I had them 20 years or so before buying the Martin Logans.

I am beginning to become intrigued enough to power down the Martin Logans, let the charge die away over a week or so, then power them up again with such bellwire and see if the sound changes once they are fully powered up again.

Down the rabbit-hole......

What do other people think?