Equipment priority for powercords

If you have a power conditioner with an iec that's where everything gets benifit. If you have multiple sources then on the pre. --Just one source? Then the CD player.

Unless I misunderstand your question, there can only be one possible answer. If your goal is to get the best sound, put it where it makes your system sound the best. There are no "golden rules" about such matters. This will require some time and experimentation, but that is what it always takes to maximize the sound. If you can't hear any difference as you move your best cord around the system, I would sell it and buy some records.

I agree with starting with the power conditioner if it has an IEC. Is is where the power starts for all components (the wall) and it therefore will affect the whole system. The CD sourc is a good second choice or amps. You may need to experiment there.

My reasoning for the 2nd choice as the pre. Say you also do vinyl. A killobuck cord on the cd player ain't gonna help your vinyl. So if it's on the pre--it helps both.