Date: 1927, Owned by Craig Parmerlee
The owner of the instrument pictured here remarked that he was surprised that the small bell plays in-tune. Apparently, on all other double bell eupohoniums (not Conns), he has played, the small bell was "impossibly flat in the upper register." The reason intonation is so good on this instrument is believed to be because "When you look at this Conn, it is different from most double bell euphoniums because the instrument splits early on - about 25% into the instrument. That allowed Conn to maintain a really true cylindrical bore for the small bell, and a very nice conical bore for the large bell."
The instrument pictured here has been rebuilt, restored and refinished in silver plate with gold wash bell as was very common in the 1920's. The large bell of the 58I has a diameter of 11", the small one 6¼". The bore size is a #5, which is 0.562". The 58I was produced between at least 1924 and 1927.
What Conn said in 1926:
In these models are combined the advantages of the curved bell, which is adjustable and detachable, and the extra bell, which enables the performer to use echo or trombone effects to give variety and life to the tone coloring. In one sense, therefore, these instruments represent the highest development in euphonium improvements, for there is nothing lacking. To the smooth, accurately proportioned sound passages from the hydraulic expansion process of manufacture has been added the famous Conn light acting valve mechanism.