Ok I just received the Stereophile issue and read the review. Jeez! There is no impedance mismatch between the Dartzeel pre used and the 7b SST-2.
Furthermore, JA's measurements conclude that the 7B SST-2 "offers up textbook measured performance and usefully high power." It will be interesting to see if Stereophile will do a follow up review
, especially given the dissonance between the amp's measured performance and MF's listening impressions (notwithstanding the issue with the replacement unit etc...).