It's break in as grannyring described. I had the same issue with mine. Also see the attached video where they talk about the glare at 12 min and the result after break in at 17 min.
PURITAN PSM156
Dear friends off lately I had installed the PSM 136 puritan power conditioner and was very happy with it the sound was well separated cymbals had that shhhhh to it and the noise floor was very low considering all that fact I went one step up and purchased the PCM 156 with the ground master I installed the same for the last 3 days but I somehow feel all the traits of the PSM 136 is missing What should I understand from this your opinion would be appreciated.