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

As sure as some cables change the sound qualia as perceived by some brain , it is sure also as in the case of some power conditioner , they can degrade the quality of sound or improve it for some amplifier or some system choices and not from other ...

My own power conditioner for example is not so useful with the Sansui alpha , it degrade the sound but is useful for my other low cost system , it improve the sound ...

For some higher cost power conditioner or power cable , i partake the opinion of carlbads2 as i already said , they can make a difference or not , it is system dependant as he explained well above ...

Now this thread for sure will degrade in a battle between subjectivist who knows quality exist for the ears as a subjective experience of the gear and those objectivist who claim they dont exist if it is not measurable electrically with tools ... The ears being for them an illusionist not a real tool...

I am neither a subjectivist nor a subjectivist ... Then i dont refute subjectivist claims about the power cord because i know by my ears that it is possible to affect the sound positively or not at all with a power cord ...

In the same way, i know as objectivist claim , that the quality of the design is not merely only grounded in human subjective taste , but as they claim must be grounded on some electrical measures as such , but certainly it is not always such and it is not always enough as rightfully claim subjectivists, and it is my opinion , they are grounded also in psycho-acoustics measures ...

I am neither a subjectivist nor an objectivist ... Why ? Because i studied, read about sounds and perceptions , and i experimented ...I am not a fetichist of the mere gear or of the mere  electrical tool ...I believe first and last in the correlation between gear and tool and the acoustics context and the brain ...

«Truth dont invoke nor provoke and dont need a scapegoat and cannot be caricatured» Anonymus thinker 🧐

@curiousjim

In my case $120. Audioquest NGR-2 (way back when). Since then, haven’t just drank the KoolAide on PC/power delivery. I chugged the entire pitcher. (I’m the guy who did the "audiophile power cable" survey a few months ago).

I’m sure there are cases where all the stars line up, power delivery falls into place quite nicely (as suggested by @carlsbad2 ), and the factory-provided/hardwired cable will do just fine. I just haven’t heard it yet. But, I’m open-minded.

For me, I have yet to hear a case where a premium PC didn’t make a difference on ANY component at ANY price. As dealer, we’ve put, literally, hundreds of premium PCs in customer’s systems. But, admittedly, my experience is limited to mostly 4 figure electronics. We currently do performance mods in the shop, some involving internal power delivery upgrades. The differences are simply stunning. I keep 2 identical 100x2 NAD power amps on hand. One completely stock. One with performance mods. The upgraded version doesn’t just sound better. It sounds like it was designed and built in a different factory to a much higher standard. Take the top 10 adjectives we like to use to describe "better sonics" and they are all there,, in abundance..

Here’s another case in point. We were missing around on the bench with a little (less than $100 retail) Class D plate amp. We were seeing how this thing might work in a cost-effective, stealthy office system mounted to the modestly panel under a desk. I have to say that, while we reached the stealthy goal, the sound quality was harsh, and down right nasty. Then I thought: "What the heck?", reached for a $69 AQ power cable and swapped it out on the outboard power supply. The sound immediately calmed down, there was some bass presence when none was there before, and the soundstage became somewhat 3-dimensional. The point: Even cheap stuff benefits from premium PCs.

@ditusa I find your post curious and it seems to be the modus operandi around this forum. Have seen this several times twice now with me and a couple times accusing another person of using an alias (to wit we all do on this forum). What is interesting is that one bears false witness if

A. one party disagrees.

B. The accused makes a valid counter point.

As I did in that your equipment is 40 years old and would not benefit from an upgrade to a $40.00 power cable, even in its finest day. You make this accusation based on me researching an old post in the archives on OCC wire where I found this Uribe19 with intimate knowledge of Neotech, the process and that Uribe19 like @magnuman both live in Vancouver BC, Canada. They also have the same behaviours in calling people stupid, dumb and ignorant in their posts. So this makes me all those people you claim. No more so than it makes you a Republican, Al Anon follower that is an ANti Vaxxer and a Xenophobe.

You can think what you like of me but do not accuse me of being someone else as I am Jacob’s Father and If I were inclined could make false allegations against you that would be to easy.

Also I will not be running to the moderators like some, I know I can take you down with my words, you have proven that.

Respectfully

Steve Snyder.

Rapid City, South Dakota.

@curiousjim

An inexpensive lower-tier Audio Art cable (I’ve since moved up the line).

At the time, without any prompting from me, my wife commented on the improvement.

Overall, I’ve found AC cables can make a significant difference.

"You can think what you like of me but do not accuse me of being someone else as I am Jacob’s Father..."

You are exactly who @ditusa  states you are.