You never stop to amaze me guys! I was just wondering which to put on top, I was planning on using the devices own feet!
But I should know better by now, you guys go the extra mile.
Now I am concerned, should I NOT stack one on top of the other using their own feet? Is that air gap not enough?
I will have to look at those pads installed, but they are a little to 'heavy' for my minimalistic taste in decoration.
There are many things to consider when placing your components regarding aesthetics, function and thermal issues.
Most importantly, you need to know that ANY stacking will affect thermal dissipation, but also, that the combo you selected is not likely to ever OVERHEAT.
That said you have the virtual freedom to stack as you see fit. Another option is not stacking at all, and going side by side.
All that said, if you are a little OCD (like many of us) you may want to place and employ means to optimize air flow to and around your components, assuming that a cooler component temperature will extend life, and sound better with warm being good and hot being less good.
To that end, the IDEAL stack would see the warmer component (the STA-10) on top. While the NuPRIME feet are sufficient to allow air flow between the components, it can certainly be EVEN MORE cooling to increase that space. This might be even more important and functional "if" you place the ST-10 on the bottom.
To that end, as many have suggested in the posts above, placing additional "spacers" between the components allows a greater airflow and this cooling effect. I have seen some suggest simple devices like even "hockey pucks".
While I know you do not have access to "Parts Express" there may be a similar online store where you are.
They offer quite a few options for "feet" to place under speakers and components for LOW pricing such as the link below. (with these, you do not use the metal screws, just place the rubber spacers under your components)https://b2b.parts-express.com/dayton-audio-drfs1-1-3-8-x-1-heavy-duty-rubber-feet-4-pcs--240-712