Best way to eliminate "common mode" noise from AC


line versus best way to eliminate "differential mode" noise from the AC line--not including AC regenerators with their attendant heat and ongoing power cost.
ptss
Yes, common-mode choke or a balanced isolation transformer, appropriately sized for the load. A number of the "line conditioner" manufacturers like APC and Belkin PureAV employ common mode chokes in their products. I have been using balanced isolation transformers with great success over the past 8+ years.

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http://i994.photobucket.com/albums/af67/mr_classe/General/APC_zpse05a8f0b.jpg

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A shielded isolation transformer can reduce common mode noise by as much as 12 dB. A balanced (60+/-) iso transformer can reduce common noise by as much as 20 dB.

Differential or transverse noise is more difficult to reduce but when it comes to power transformers, the idea is the opposite of audio transformers. You want limited bandwidth and a EI core is better than a toroid in this regard. Toroids are easier packaging and have less magnetic radiation.

Transformers are probably no more or no less effective than LP filters for transverse noise below 600 Hz, which includes several harmonics. Personally, more concerned with high frequency SMPS hash.
Thanks very much for your inputs.
I do use an Equitech 2Q transformer for common mode and some MIT products as well as good power cords and some enacom ac's.
Playing with what I have has proven that ac noise is a complex problem(at least where I live). I was hoping to hear of some new, or unknown to me, "magic".
The closest thing to "magic" may be power regenerators, like the ones from PS Audio and PurePower.
Thanks Gbart. I appreciate your taking time to be helpful but I mentioned in my initial query not including
power wasteful regenerators. I try to think green & buy the most effective,least expensive to maintain or operate, components. I think the Equitech 2Q transformer in a box & MIT combinations I use do an excellent job and are fairly economical to operate. So far I have never been able to justify investing even $3000 on a single conditioning/isolation component. But,I find isolation and conditioning extremely worthwhile and am seeking an ideal mix. I don't think a single component or brand will maximize results. AC noise is incredibly complex, and apparently growing moreso in microprocessor controlled robotics. My Spectral gear is 'very' revealing and cumulative rewards are proving satisfying & interesting. Hoping for more perhaps 'adding' a Shunyata or Sound Application product(s).
Need info/feedback. Thanks