What was the first power cable that you noticed a difference in the sound?

Without talking about cables made with unobtainium, where did you start hear a difference.

@curiousjim The first time I heard a power cable make a difference was at CES in 1990. I was visiting George Cardas where he was showing of a set of Magnaplanar MG3s that had a custom wood frame that was built to be both stiffer than the original frames and non-resonant. He took an interest in the amps we were showing and I was interested to see how the speakers worked with our amps, so I brought our MA-1s over after hours. We played the system for a while. It sounded good, better than I remember MG3s ever sounding.

George then suggested we try a set of his power cords on the amps. We did, and immediately the system got better across the board. The bass, which by comparison seemed a bit ponderous, became nimble and fast with better impact. I was not sure that was the difference so I arranged the cables behind the amps so I could switch them in a couple of seconds without having to shut the amps off. The difference was immediately audible in either direction- better with the Cardas cables and worse with the stock cords. I bought them on the spot and still have them.

Years later I sorted out why they worked so well. The MA-1s draw a lot of power and the voltage drop across the stock cord was enough to reduce the filament voltage and B+ at the same time- so the amp made less power. The Cardas cables simply had less voltage drop.

The take away is if you have a lot of current draw you’re more likely to notice a difference with power cords. If the equipment has well regulated power supplies with good headroom you’re less likely to hear a difference. That explains why power cords don’t seem to affect our MP-1 preamp or class D amps all that much, but affect our OTLs quite a lot.

So you might look to see if power draw has anything to do with it in your setup.

To me the biggest difference was when I bought and tried the AQ Dragon source for my ARC Ref 9 CDP. I originally was using the Shunyata Sigma digital PC. It was so great that I will be also buying it for my ARC ref 6SE and sell my Shunyata Sigma HC PC.  

Been running a Synergistic research cord for around 3 weeks now on my Lyngdorf 3400. Didn’t expect to hear any difference especially since Lyngdorf says their amps are impervious to cords. I absolutely hear a difference. It sounds bigger and more bouncy I would say. It’s got different biullets you plug in basically dark/ medium / and detailed or bright. I like the dark one the best I think but an absolute difference and can change them on the fly

In a good system a $2K Audio Quest Hurricane can be a bargain for the amount of sound quality gained for the money. 
 

This is the whole reason high end wires are around, for a person that chooses wisely, he will always be getting a bargain for what ever the cables cost.

I remember having a system at the $5K / component level and my dealer sent me a set of cables costing $2K… I thought that was simply ridiculous, until I heard them. I could not have gotten that improvement by swapping components for less than $5K. The sound quality improvement of any given component (wires included) needs to prove itself. One of the important steps in high end audio is to put in the time to learn what is worth it given your values and system.