Experimenting further, I moved the Blue Circle Thingee from the Cullen Cable power box (a square strip) directly to an unused outlet which is situated about 8' from the one that my integrated and SACD player occupy, but shares the same line.
That made an even bigger difference, cutting down the 12' total length (outlet to Cullen Cable box and the Thingee with a 6' PC) in half. It appears that the closer the Thingee is to the source, the better the filtering and conditioning.
It's almost as big a step in improvement as first inserting it the older way.
All the best,
Nonoise