Power Conditioner vs A/C cables

I've had systems that as I added AFTER a good conditioner and master coupler, the system got noisier. AGAIN a buddy and his BIG ol Power cables weren't shielded properly and just screwed the whole system up..

I swap the PCs out for the right kind of cable, everything else became kind of secondary.. I was 45 years old then, I'm 66 now..

Another thing I've noticed in other's systems they use a PC that are WAY to big for the application..  Bigger is actually worse in some applications..

I've notice where it's being used makes a difference AND the quality of the power supply in the piece of gear.

Crap power supplies benefit more from a BETTER construction (filtering) than (for example) a Mac..

DAC, routers, Laptops (not so much),

Phono Stage, Pre Amp, Streamer/Server, Power Amps BIG TIME..

Reel to Reel is still in ? stage for me, cabling is a mystery vs quality..

I just spent two great day in the Barrios listing to street music.. No I ain't sayin where...BUT it wasn't in the US WOW... I never ate so much good food and seen so many masked beauties.. Fantasyland!!!

I never saw anything BUT heavy copper. Serious tight a$$ jammin' going on.. Electrical tape everywhere, chain hook the cable drop it on the gravel.. Good music.. mercy..

Regards

I decided I need power conditioner with filtering and strong overvoltage protection anyway.  I bought Furman Elite 20PFi and placed it on the shelf below DAC and amp.  I concluded, that if power cables have effect on sound, it will be proportional to the length of the cable.  I built very short (1.5ft) shielded cables using Belden 83803 and Wattgate connectors.  

I believe that good power filters are very useful. Both to filter your AC, and to block digital noise from the digital/switching power supply components (computers, TVs, other). This means a mains filter AND a 2nd one, can be fairly simple, just for the digial /switching stuff.
Power cords i have tested many times and fail to find an value, unless you are replacing something deficient- which is not all that uncommon, but easily avoidable for $20

A power condition that generates its own pure sine wave output is worthwhile to completely remove line noise.

Shielded power cables stop Electromagnetic Interference emanating from the cables. Certainly EMI is present in the environment, but it is still important not to add more in close proximity of equipment.

If you are really serious, both are crucial!

Power ‘filters’ are terrible, they normally take more away than help the sq. You want a power regenerator or use balanced power to get the best out of your system.
How much to spend or how much improvement you are going to hear all depends on the quality of your system and your hearing. To actually state the a $20 cable is all you need is foolish for example, even a pioneer system would probably see an improvement with a $20 cable. A dealer friend did a demo for me on a system that cost around $20k. He made 1 change that I couldn’t see what he did and it made a huge difference in sq. All he did was to replace the stock power cord on the Mcintosh amp to an entry level red dawn nordost power cable. This was almost 20 years ago and ever since, I have always used the better power cords on all my components, which have been much more expensive than the red dawn