AC Conditioners: Must Have Tweak or More Voodo

Fixing the wiring first sounds like good advise. -- As to AC accessories, my guess is they all have their own character. As an example, I've tried the PS Audio P300, Ultimate Outlet, and Juice Bar (and still own and use all three) with a single brand of upgrade power cord (Silver Audio Power Burst). The Power Burst gave tighter bass and more clear mids. The Ultimate Outlet improved the blackness around notes with a 'mellow' presentation, the P300 also improved blackness but resulted in a very refined high end. Since I feel most systems overemphasize the high end, I nearly discarded it, but upon further listening concluded it did not exaggerate but rather 'revealed' the high end (just an impression without factual basis). I'm using the UO in a dedicated headphone setup and the P300 in my main system (but I've read that you can use them together). The P300 didn't have enough outlets, so I used a relatively inexpensive power strip that allowed use of your own power cord. After having cords loosen in this strip I bought the $200 Juice Bar on a 30 day trial. No contest, immediate improvement. -- I neither have the time nor money to compare all or even many of the different power cords, conditioners, outlets, etc but from this limited experience believe that for a given system they will all have an impact in different ways in much the same way that different interconnects and speaker cables give different results. Good luck.

I am using an Audio Tekne power tranformer and I plug everything into it including 2 amps. Works better than the ps300, titan power block. Since I couldn't put dedicated lines in without ripping the house apart this was definitely the way to go. Audio Tekne is a relative obscure company in the U.S. but has great products. The voltage changes where I live are common and this tranformer cured that problem.

i've not yet tried ANY power conditioner in my system that failed to degrade the sound in one way or another. as sean and others have suggested, an up to-date and code electrical wiring upgrade should be your first priority, not just for your nascent audio system, but your overall sense of safety and wellbeing. once you've got the proper wires going to your rooms, have high grade outlets installed, at least in your "sound room" (lots of threads on these). from there, all you should need are good power cords (more threads on these) and, perhaps, a secondary surge protector (yet further threads on these). BTW, wouldn't it be proper to change your moniker to, say, "cwusetabelondon." :o) -kelly

Line conditioning was still advantageous in our 75 year old farmhouse containing antique wiring & no ground lines. I use Chang Lightspeeds which also provide integral surge protection; the "third leg" path to ground is 'basically' there via the grounded-conduit itself (it's not as good as a third-wire ground connection but is better than nothing). So if you at least have conduit, BX, or Greenfield then there is likely a metallic ground path from the metal outlet boxes back to the service panel. You can take advantage of that ground path by simply installing three-prong outlets, which connect the 'conduit ground' to the outlet's ground-prong via the metal outlet mounting flanges. Use a high grade outlet for the audio of course.

Plugging amps direct into the line, or via a conditioner, is an old debate. My results vary depending upon the amp in use & the upgrade AC cord in use. For amps that work well with a filtered upgrade AC cord, I plug them directly to line (the filtering is in the cord). For amps that work well with unfiltered upgrade cords I plug them into a 'Chang 9900 Amp' (has 30 amp capacity = low surge impedance). The Chang was plugged into the house wiring; later when I added a dedicated line I plug the Chang into that instead with good results.
For source components I have a Chang 3200 (15 amp capacity) which provides simultaneous filtering & transient protection. I also use upgrade AC cords on source components, each cord selected for best results with each specific component.
The PS Audio may also do a good job for you, but the only way to find out is by trial & error. I don't personally care for their inefficiency; much wasted power & much extra heat in your room (this makes you not even want to have your system turned on during hot weather & also significantly increases cooling bills during air conditoner season).
Further down the road I installed the dedicated line, which further enhanced all the previous improvements. Having a dedicated line doesn't mean that you do not need line conditioning; having line conditioning doesn't mean that you won't benefit from a dedicated line. They're each helpful standalone, & they're even better when combined.

Living in a 650 sf cinder block Army barracks puts me in a similar position. All of my outlets seem to work and all are grounded (well, they have 3 prongs anyway), but the whole system seems to be designed to support a TV, a fridge and a microwave and not much more. Because I had similar concerns and no possiblity of getting my "landlord" to upgrade my wiring, I decided to go with a P600 for my amps and speakers, augmented with a Chang 3200 for the front end components. The sound has improved tremendously (and continues to improve with PC upgrades), but I'm uncertain how much protection the Power Plant provides. I would think that it would be bullet proof since it is generating a 'perfect' sine wave power source, but changing fan speeds (plugged into the wall across the room) occasionally generates a crackle from the Martin Logan's. Other than that, this seems to have worked well for me and I've sustained no damage despite frequent blackouts and brownouts here in the Mojave. PS - if you decide to get a PowerPlant with multiwave, remember that if your Michell has an AC motor, it won't work right when.