Changes in DAC Presentation - Need Advice

I believe that you have a problem on the dac.   Breakin  is questionable at best and no major swings in audio should occur.  I use a Microsoft surface as a roon source, ultra rendu via usb to an audio gd r7 and the sq has been incredible and consistent since arrival

+1 @tennisdoc56  - break-in can offer long-term gradual improvements to many components but to swing SQ mid-song by such a noticeable level sounds like a major fault.  

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I would try to exchange it for a new unit

i cannot tell you what IS wrong, but can say with a lot of confidence that it is NOT a breakin issue....perhaps you would notice a gradual change in SQ, but certainoy not "flipflops"....