Power - where to start? Mains, chords, conditioner, filter?

In my opinion, the place to begin is with one or better yet two dedicated circuits with 20 amp breakers and wire runs of 10 gauge although 12 gauge would work. In addition to that use high-quality AC outlets. Porter Ports sold here on Audiogon by Albert Porter is a good place to start that won't break the bank.
The use of dedicated circuits usually is a big improvement. If you can't have dedicated circuits at least upgrade the outlets if you have not done so yet.

Great advice from lak, dedicated lines made a big difference in my system.  I also use Porter Ports from Albert.

An alternate route to a dedicated power line might be to purchase a YETI power backup system
https://www.goalzero.com/product-features/portable-power-stations/

A fellow audiophile just made me aware of this unit
- generates a perfect sinewave
- works just like a UPS 
- but with a larger capacity
- handles large transients with ease
- on his system a YETI 1000 will run the ENTIRE system for over 5 hours
- you can leave it plugged in - or not

He swears by it, but I have not used one, so it’s hearsay, but we have emailed many times, so I do trust his opinion and judgement

I would also get a good power cable for the streaming device - take a look at these power cables...
https://kleinnovations.com/kle-innovations-klei-products/klei-ac-power-cable/klei-gpower2-ac/

All of their products are first class and provide stunning sound quality

Hope that helps - Steve

A power strip with a big coil is the entry level:
https://amzn.to/2Ow03Tg
Furman makes bigger, more expensive units. Look for LiFT and SMP.

Shunyata is also a good idea.


Power cords need not be very expensive but using shielded for digital/streamers that are near your analog is a good idea.


Keep power adapters outside your "clean power zone." or use a second strip for them. Especially good for network devices like routers and switches. Alternatively, use a power conditioner with multiple filtered banks like Shunyata or Furman offer. 

There is no purpose, advantage, or benefit from adding potentially expensive, elaborate, or intrusive "upgrades" to your power delivery system if you do not first examine, study, and measure you're current service what is the voltage what is the power factor what is the distortion level and noise of the existing line that is the place to start!