The 307A was just "reviewed"* in Issue 17 of Tone Audio, which can be downloaded here:
http://tonepublications.com/MAGPDF/TA_017.pdf Review on page 135. The reviewer loved it, of course.
In the same issue they also reviewed the Lehmann Black Cube Linear.
Also in the same issue, some really interesting music reviews. (One of two major reasons I read the mag, the other would be the amazing photography.)
* in quotes because Tone Audio's reviews are consistently terribly inadequate