I've always had good results using the Omega Mikro active PCs.They offer filtering of the third-prong (common),where all the digital artifacts dwell.There are two colors-red/in-phase and blue/inverted.The 100W version can be had from their website for $550 and has a return policy.
The red/blue issue depends on how the transformer is wired-you will notice a difference.
The red/blue issue depends on how the transformer is wired-you will notice a difference.