Inconsistency in System

I am experiencing a rather large degree of inconsistency in the quality of the sound from my system day to day or even within the day at different times. At times rich, warm, inviting....other times veiled, harsh and way bright. My hunch is this is power related but am not sure. Does anyone have a suggestion on what might be causing this variability and if so, what I might do to correct problem?

System Components
Wadia 3200 Transport
Musical Fidelity TriVista21 DAC
Audio Research SP16 MK II Preamp
Musical Fidelity A308 Amp
Magnepann 3.6R speakers
Transparent Ultra interconnects
Transparent Music Wave Super Speaker Cables