Here's a polarity conundrum. I have a First Sound preamp that inverts polarity. As a result, I reverse the system's polarity at the speaker terminals (+>-, ->+). The Scott Nixon Tube DAC inverts polarity as well. How can I use the TubeDAC in a system with other sources? Seems to me, the TubeDAC signal is going to ultimately be out of phase while the other sources will be in phase, or vice-versa.