I recently bought one of these (see
https://sites.google.com/clarinetpages.net/clarinetpages/others/albert-system-clarinets/penzel-mueller/penzel-mueller-improved-albert-system), because I really like my Penzel-Mueller regular Albert. I wanted the alternate left hand E flat/G sharp key and was curious how much better the clarinet's intonation might be. Also, I had been on the lookout for a used German system clarinet with similar keywork, such as a Hammerschmidt, but hadn't found one.
It sounds great, but I was intrigued to find that it is not really an Albert system horn. The bore does not start to widen just below the bottom F/C key as in Albert clarinets. Instead, it is cylindrical (0.58" dia.) almost down to the bell. My Penzel-Mueller regular Albert is actually an Albert, having 0.58" for the top joint and 0.63" just below the bottom F/C key.
As is well known, even regular Penzel-Mueller Alberts were influenced by German system design. They have 5 rings and the wraparound register key is near the 10 o'clock position rather than being at the top.
In the case of their Improved Albert, the makers seem to have gone full German. Not only is the bore German system, but the horn has 6 rings and also has the forked F/B flat correction key that closes when the 5th ring is depressed for E/A.
"Improved Albert" seems to have been a term Penzel and Mueller coined for marketing. I wonder if they were attempting to compete with the Selmer Improved Albert clarinets that many jazz players liked. Perhaps these Selmers, being made in France rather than by German-American immigrants, actually were Alberts?
