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

It is for sure a rational and very interesting explanation...

We are lucky to have him here...

As usual, @atmasphere has the most informative, scientifically based posts and explanations with respect to electronics and audio equipment.  

I fully agree.

I now have mono blocks and there’s an old style Cardas Clear Beyond for sale in Canada. If I buy a new style cable that has different plugs on the ends will there be a noticeable difference in the sound between the A style and the B style?

Thanks.

Agree with others noted above dedicated lines should be done first but not necessary. I started with Homebrew PC’s, then Kimber Kable PK 10 Gold which was a noticeable improvement, then to Nordost Vishnu, WyWires Silver to Platinum which are great and can be had used at a great price for how they sound. I recently picked up a slightly used Nordost Valhalla II which is an incredible PC but even used are a little crazy. Don’t forget the wall outlet/receptacles. Recall someone previously mentioned don’t bother and just get an AQ Power Conditioner; not saying that’s not a great device, but even with my PS Audio P10, Dedicated lines, with AQ NRG outlets and WyWires Platinum PC is still noticeable on my P10 feeding all source components and preamp. 

Just this month, after adding CruzeAUDIO Maestro outlets to my systems dedicated line and hearing very noticeable, immediate improvements in detail, imaging, bass control, blacker noise floor etc (which to my mind defied all logical explanation), I decided to take the plunge and see what a power cord upgrade could do for me, another thing that sounded like it shouldn’t have any effect on sound. Since the reviews I’d read for Maestro outlets mentioned a symbiotic relationship with Sablon Audio power cords that brought out the best in both (basically, 1 + 1 = 3), I purchased a Sablon Audio Corona power cord with the Oyaide C-004 upgrade to replace the stock made in Taiwan cord, running it from my Creek Destiny integrated amp directly into the Maestro outlet.

Wow! More MORE: better bass modulation, tighter definition of of all musical elements, finer pinpoint details and imaging. More clarity, without increasing brightness. So… my first foray into upgraded power cords was a rousing success, with the only downside being an urge to upgrade my current MIT speaker cables to the MIT Magnum M1.3 model to allow more of that beautiful sound out 😉