Based on what I have read it is generally better to hook up the source components to the SP-15a and my tube monoblock amps to the EP-15a.Yes I would agree with that -- it's how I have my system configured. I have both units on the same dedicated circuit, so most powerline noise is at a minimum anyway. And the SP (balanced power transformer) gets rid of anything else through 'common mode rejection'.
I have all my source equipment plugged into the SP, because those devices benefit most from balanced power. The EP (which is at the front of the room between my amp and (powered) electrostatic speakers support those devices. Tube amps in particular, benefit from the VOLTAGE REGULATING capability of the EP because otherwise tube bias will fluctuate with changes in line voltage.
Neil
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