I suggest that you do not use individual adapters for each cord. Either re-terminate with quality plugs that fit for your country (can still be cheaper than buying new vs used), or get a US extension cord with the number of sockets you need, then just change the main plug to suit your wall socket. I am doing the same, we have Schuko 220 V here in Germany, but I use a audiomagic stealth power conditioner with the right voltage but US style sockets. I only put a German power cord in front from wall to the audiomagic stealth unit. From there I use all US power cords with their original plugs.
I have tried using travel adapter plugs before and it is clearly degrading the sound and ruins what you might gain from the cables in my experience. Changing the power plugs is easier than re-terminating the interconnects usually because the wires are fixed with screws in most plugs. Just make sure you know what you are doing, if not ask someone to do it for you.