Various power cables, which would you put where?

For now, keep the Marinco connectors on the cables.

DH Labs Power Plus => use on Exposure 2010S2D amp because this is the largest cable (11awg) and you want the most amount of current available for the amp.

WireWorld Aurora => use on the PS Audio NuWave DSD DAC. This is your best quality cable because it’s silver-clad instead of silver-plated and it’s a larger awg than the Furutech cables. You want the best quality cable on your source. Essentially, if the sound quality is not there from the source (beginning), there is no magic you can use to get it back.

Furutech G320Ag-18 => use on the headphone amp because the connectors on this cable are gold-plated pure copper (FI-15ME) and are better than the Marinco (brass).

Furutech FP-314AG + Marinco => use on the PC. The brass Marinco plugs work effectively on a PC.

Once you have all this in place, listen to some music through external speakers on the amp. The Marinco brass power connectors have a lot of attack and clarity, but can have a tendancy to sound harsh/sterile/solid-state. If you like the attack/clarity/punch, but want to back off on the harsh/sterile character and provide a more refined sound, then upgrade the DH Labs cable with Rhodium plated FI-15 Plus. If the attack/clarity is way too much and is too forward and "in your face", then go for Gold plated FI-15 Plus connectors. The gold-plated will sound warmer and it will definitely be more laid back.  Make sure you get the FI-15 "Plus" connectors (not the old FI-15e).

Heh, sometimes you don’t realize something sounds harsh/sterile until you hear it without that harsh/sterile character. That was the case in my situation as I used to use all Hubbel hospital outlets and male plug connectors (all brass). I was working with different gold-plated connectors on my system upstairs and just for the heck of it, I popped in a Wattgate brass connector. The result was fast and clear, but it was definitely more sterile/cold sounding (less emotionally engaging and less organic). I suddenly thought "hey, this is what my system downstairs sounds like!!" Then I removed all brass elements in my A/C line completely!

As far as the outlet question, an upgraded outlet will definitely improve/affect the sound, but not as much as a power cable. Generally, elements in the A/C lines that are closer to the equipment power supply will have more of an influence on the sound. That’s not to say that an outlet won’t make any difference, it will just be more subtle.

I generally recommend that people start at the equipment power supply itself, beginning with upgrading the fuse and then work outward from there. The fuse will have a significant impact to the sound quality, but the fuse and power cable work hand-in-hand so both are very important.

In your case, if you decide to upgrade the DH Labs cable to rhodium connectors, I would upgrade the fuse in the amp to a rhodium plated Furutech at the same time. Then you can burn in both the fuse and power cord connectors together. You can upgrade the fuse in the headphone amp also, If you wish. I could not see if the PS Audio DAC uses a fuse, so that is unclear.

At this point, it really depends on if you connect all your components straight to the wall or if you use a power strit in between. The typical power strips are horrible and will further degrade any improvement you have. They can have thin/cheap metal conductors internally and small gauge wire (such as 18awg). It’s always best to connect straight to the wall (especially for the amp). If you must use a power strip, look into a very good one. The Emotiva CMX-6 is very good for the money and has a nice small filter/conditioner built in. You can also upgrade the power cord for it to something better if you like. However, be aware that the internal wiring on the Emotiva is 14awg. If you want something better, it will cost you $$$$.