which power conditioner unit?

The best power conditioner is none at all, if you don't have nasty power. Be sure you need it, a voltage regulator might be more useful. Again be certain you have bad power. Dedicated lines work great in many cases. YMMV

Your own equipment may be the worst offender ... in a sense "You've hired your own Assasin"

Dacs, Switching power supplies, Oscilllating clocks, Diodes, and more,(any thing that switches on, and off at a high rate) can add noise back into your system's power supply.

Look for a Power Conditioner that filters on the back side or is Bi-Directional

My combination consists of an Exact Power EP15 to generate square sign waves, and Foundation Research's (LC1) to filter Bi-Directionally

There are a few DIY filters that you can istall on each of your dedicated power lines (assuming you have dedicated lines). I think the Magnam website is where I got my info and I found this to be the best of what I have heard versus the thousands for a line conditioner.

Happy Listening.

There are too many variants to make for easy categorization and too little information disclosed about how individual units work. Thus, Nsgarch's descriptions are fine but there are other variation and permutations (automatic voltage regulation, battery-power, etc).

The bottom line, for me, is to determine if you have a problem that needs solving and then find the solution. Adding gadgets based on someone's encomium won't do it.

Kal

Kal