Phono preamp power cable not long enough. New wall wart or use an extension cord?

That would kill any dynamics.   

rhljazz, If what you say is true, have you had any second thoughts about the Shunyata?  There's no technical reason why the Shunyata would not work well with a wall wart power supply or at least AS well as it works with any other component you plug into it.  So, I am wondering if it is doing something subtractive that can be sensed when you use it to power highly sensitive circuits, like your phono stage.  But there is one thing you might check; the turntable motor can put noise back into your AC.  Unless the Shunyata outlets are well isolated from one another, you may be hearing noise induced by the turntable motor, when both the motor and the phono are connected to it.  Try running the tt off a completely different outlet with phono connected to the Shunyata.