Before even considering a line conditioner or any cable upgrade you should insure that your AC outlet is not on a switched circuit, the contact point of which is about the size of a pencil point (as it was described to me). Then purchase high quality hospital grade or audio grade outlets (porter ports, watt gates etc.) At this point you haven't spent much money and the difference you will hear will be profound. Then I would upgrade the power cord until you feel that with your existing setup that you have the clearest most open highs, cleanest tightest most extended bass response and the blackest (quietest) background. At this point you can decide if you need a power conditioner. Like Thorman says, "don't buy a power conditioner unless you need one". Beyond this point it's a matter of synergy and I agree with Dedicatedaudio when he says work downline from the source.
Cables /power conditioner- Order of importance
Spoke to a few dealers regarding cables/conditioners and most of their opinions seems to differ. If youI wish to upgrade cable/conditioner but has limited budget, which would you upgrade 1st. Power conditioner, speaker cable, power cord, interconnect? What would be your order of importance? TQ. Happy listening