I had one power conditioner and auditioned another. In my oponion there was little to no improvement from either device. I deicded to try one more time and purchased the Puritan PSM156 earlier this year. I was shocked by how much better everything sounded with the Puritan.
Always been a little skeptical about these types of devices but Purtain, at least in my system, has improved the overall sound quality and I guess either eliminated to dramatically reduced the interference.