Almarg's remarks make good sense. I note that the "Signature" version of the Rhea uses coupling caps that are twice the value of those in the non-Signature version. (4uF vs 2uF, respectively.) The larger caps would go some distance to ameliorate the problem noted by the Stereophile tester. That is a worthwhile upgrade and could be done rather cheaply if one knows how to solder and owns a non-Sig Rhea. The output impedance at 20Hz would be halved.
