Line Conditioners or Power Filters?????

As Sugarbrie states, dedicated AC lines provide excellent benefits regardless of what else you do.

As for your original question, I'd recommend investigating the Foundation Research LC-1 and LC-2 dedicated and passive in-line power conditioners. Marty DeWulf of Bound for Sound reviewed these last August and claims these to be the best in the business and purchased them for his 'big rig'.

I've been using these for over two years and the benefits are tremendous, including the elimination of any negative sibilance.

BTW, they come with their own built-in power cable and cost about as much as a good power cable.

-IMO

Psychicanimal make a good point. Except that his pre-digested responses are typically more detrimental and potentially misleading than other's if not for the mere fact that his pre-digested responses often times infer (as in this case) that he has none.

Finally, one's IQ should never be deemed as a justifiable excuse to indulge in self-deception. These acts simply render others helpless or give the sense thereof.

-IMO
(all those who believe in telekenisis, please raise my hand)