Should the better AC cable be used on Amp? Source?

You can make it very easy for yourself. You use about 5 numbers you know very well. You first put the better cable on the source. Later you do the opposite. Normally a cable has more influence on a source. There will be situations that the amp will do more. Wenn you use a cable with a better AWG, you will get a better result on poweramps.

My best Pcord genesise 1.1 has always Been on my cd and for over à year i was quite happy with the Sound.Last week having read the subject i dividendes to have à truc and that´s what i did so i plugged it to my power distributor to feed all what was connected,every item took the full benefit of it except my amp plugged to ac wall the Sound dramaticly changed infact it did creat Space between each instrument ...3D Sound . the power cord is still i did not change this configuration the whole system is breathing à pur oxygene.thx to you.

I think we've all been where you are at one point in time.

I always felt it was better to put the more robust cable on the device that drew the most power, which was mostly the amp.

But as has been expressed, sometimes using it on the pre amp had it's advantages also.

So, what I did was bite the bullit and traded in the lesser cable so that both cables were the same.

I ended up replacing all my power cords with the same brand and after a careful audition settled for the top of that line.

It's an expensive way out of the conundrum, but in the end it's been worth it.

Upscale isn't clear enough. Do you have power condtioning anywhere. What is it.
If we assume an excellent well made cable, ie MIT or Shunyata, Cardas...
ask the manufacturer. Many factors about the cable affect where it is best used. Using 1 good classical guitar cd and your ears should let you decide for yourself. What cd player. What amp. Is your absolute polarity right for cd player? pre, amp or receiver-1st step. Ask if you don't know about it. Do you have polarity inversion switch.
Leave everything on overnight and for the next day,
Do listening after 8 next night. Should be easy to tell if there is in fact an upgrade.

Upscale isn't clear enough. Do you have power condtioning anywhere. What is it.
If we assume an excellent well made cable, ie MIT or Shunyata, Cardas...
ask the manufacturer. Many factors about the cable affect where it is best used. Using 1 good classical guitar cd and your ears should let you decide for yourself. What cd player. What amp. Is your absolute polarity right for cd player? pre, amp or receiver-1st step. Ask if you don't know about it. Do you have polarity inversion switch.
Leave everything on overnight and for the next day,
Do listening after 8 next night. Should be easy to tell if there is in fact an upgrade.