Isolation Platforms under Line / Power Conditioners ..any thoughts ?

You can reduce or virtually eliminate the hum in your transformer by using another power conditioning unit before it. Experiment.

I should have said "may......hum". PS Audio made a Humbuster for example, no recommendation implied.

I have found the judicious use of Sorbothane pads and cone an excellent, very inexpensive way to damp and eliminate vibration. A 1 ft by 1 foot Pad can be custom cut to add to or replace the feet on any equipment you use. Look at sorbothane's website and search the web for great prices.  If you dig deep enough you will find many custom vibration control devices sold  on AGon incorporate it in their designs

Forget about Symposium get the cheap stuff for mediocre sound.