If you have a Wurlitzer 200 or 200A model, you may have noticed that the very top five notes (G#6-C7) do not dampen and freely sustain. This is because there are no dampers on these top five notes. It is completely normal and nothing to worry about. On these top notes there is a small damper arm, but no longer arm that has a damper felt to mute the note. This is why the note rings out.
The reason the Wurlitzer is designed this way is likely for a couple of reasons. The first is that the reeds and reed-bar shields get narrower towards the very top of the piano. This means that there may not be enough space to have properly functioning damper felts on the very top notes.. The second is that is likely that when Wurlitzer were designing their electric piano were emulating the design on acoustic pianos. On upright and grand pianos, there are no dampers on the top 20 or so notes, though this varies from piano to piano. It is because the decay or duration of the string when struck in the upper register is very short. Therefore dampers are not needed.
On the Wurlitzer pianos, the decay is similar with the reeds in the upper register, but because the piano is electronically amplified this decay length can be increased. This, along with less action parts needing to be made could be the reason why this occurs. Regardless, the top five notes sustaining are inherent in the design of the instrument, so all is fine if this happens.
Wurlitzer was also company that made many acoustic upright pianos, so certain parts and ways of designing would have been similar in the acoustic and electronic instruments they were making.
