From postings on this site (notably comments made by Steve F. and Tom T.), I learned of the Cambridge address locations of the earliest AR manufacturing site (23 Mount Auburn Street) as well as the AR listening room (52 Brattle Street). And of course, many of us that own 60's speakers or electronics made by AR are familiar with the predominant manufacturing address at 24 Thorndike Street, which is listed on tags and plates attached directly to the audio equipment. For information only, I w