The main source for Bach's Solo Cello Suites is a copy made by his wife, Anna Magdalena, as no autograph has been preserved. As is evident from other copies, the actual musical text poses few problems. However, the layout of the connections, particularly important for string instruments, is very imprecise, forcing the editor to make delicate choices. Our HN 666 edition includes two parts, offering on the one hand the Urtext edition - with preface and comments -, and moreover a part specially studied for the practice. The “Studien-Edition” presented here contains the Urtext part, enlarged with a reproduction of the copy of Anna Magdalena. Thus, the cellist and all those who love these works will be able to get an idea of the existing problems, which are still the subject of multiple controversies.