This really depends on a couple of basic things:
1. how "dirty" is the AC power in your house, especially on the circuit that you plan to run your audio gear on.
2. How sensitive to this noise is your gear?
and
3. What's your budget.
I have two main goals when it comes to power -- lower the noise as much as possible (duh) and do it with as little between the mains and your gear. I'll also add that if you can, it is also very helpful if you can separate digital gear from analog gear (and switching power supplies from linear ones. Also, with a lot of gear, though not all by any means) changing a switching supply to a linear one can bring very positive changes. As with everything though, YMMV. Some switching supplies can be quieter than a cheap linear, and even sometimes shielding a switching supply with copper foil/tape can help.
If you're budget is limited, then a really good outlet strip ( no surge suppression, MOVs or loose outlets) can be fine, especially if you want to take the time to rewire the outlets with a heavier gauge wire, and maybe some other simple upgrades. Also, replacing the plug with something other than the molded-on OEM connector with something else -- doesn't have to be a bespoke plug, just something solid and preferrably hospital grade -- marenco is a fine choice. This is also a good strategy if your audio gear sounds decent enough already. -- a good, hospital grade plug and outlet with clean (possibly with polished contacts on both ends), and a death-grip wall socket, can often do far more than you might think. Also, some very inexpensive industrial power cords -- such as the Volex SJT 14 gauge -- can often be a nice, inexpensive upgrade. Use these with new ends of the type mentioned above, and maybe something like a Porter port, and you've most likely taken yet another step up in sound quality/lower background noise.
Personally, I truly dislike APC gear -- it is very cheaply made (not like it used to be in the early 80s) and has all kinds of things that make more noise than they filter out. Fine for computers (as long as you're not doing any audio processing, ripping, onn them.)
Watch the power regenerators too -- they can also make a lot of noise with their internal circuitry (if you have a voltage fluctuation or over/under voltage situation, they are probably you're only decent choice (that's affordable. Stay away from so-called CVT or constant voltage transformers -- the way these works makes them very prone to. generating lots of nasties.
My highest recommendation though would be to go with a balanced power unit (especially for tube gear (and even more so for Class A DHTs). I bought one several years ago and will never look back. These also can act as an isolation device. I have an Equitech unit, which is getting up in price, and there is also Balanced Power Technology -- also pretty expensive), but there are some other companies (whose names I forget at the moment) that make small balanced power units, and even a small one will do wonders for a simple system such as one you might put together with BH gear. A couple of nice things about balanced power is that it usually functions as a galvanic isolator (putting a fairly benign noise wall between your audio gear and all the rest of the electrical noise pollution in your house. Secondly, they automatically, because of the nature of the concept, cancel most common-mode noise. You can (and should?) read some of the papers on the equitech.com website -- I have nothing to sell, just a convert.
My system is very simple and I have the bottom of the line Equitech Son of Q Jr. unit, and much of my cabling is Volex power cords -- some with upgraded plugs, some just as they come. I had a large gauge, bespoke cable that feeds the Equitech box, and one leftover bespoke power cable that goes to my amp, but the DAC, Sub amps, and linear power supply for the streamer/server, and I'm happier with my sound than I've ever been since before using balanced power. Also don't forget the BH power cord kit -- very good on BH gear and is even better using a balanced power system. No, I'm not just saying that because this is the BH forum, but for some gear they really are nice -- you just have to keep in mind that they are only 17 gauge, so don't try to power your kilowatt amps with them.
So, my system uses mostly off-the-shelf volex power cords and hospital grade connectors (or unmodified volex cables (again, I use only the 177x SJT 14-gauge cables -- you can get them as short as 2 feet and up to 25, I think.
The British high-end audio components maker, Chord, recommends and uses These same Volex cables as standard. Can you do better? Yes, but you'd have to spend loads of money, and you always take the chance that it may be a minimal or no improvement over something like the Volex cables. BTW, you can buy Volex cables on Amazon or Mouser, and I'd guess that most electronics supply houses will carry them as well. Sidenote: lighter gauge Volex cables are the ones that come with many of today's home computers.
So, with balanced power, only a few, low power draw components, and no ethernet connection (thanks to Auralic's Lightning DS), my entire system is galvanically isolated from the rest of the house, has built-in common mode noise suppression, and even using pedestrian power cables, sounds like a million bucks and is the quietest system I've ever had (actually even better than an all-battery powered system I had several years ago.
Balanced power rulles, and good, tight, and fastidiously clean contacts will do an awful lot to improve your sound.
Hope this helps,
Jim
