TubeNet

When it comes to front action brasses and to sousaphones I find the American type airpath the best because the exit and re/entry angles are very open (135°) ion all valves except for the 2nd, where the tubing is too short to go around the piston casing. I have wondered when this type of valve block was introduced, but have no definite answers yet.

It has been suggested that this valve block was developed for the sousaphone. However it also has had another early application. Working with my galleries I found photos of a baritone from 1889, where Conn uses an early version very similar to what is seen today.

Klaus

I could only find one pre-1900 US made piston helicon, an 1880 Eb Wurlitzer, which has a valve block like on a top action tuba (except the slides no going down).

Klaus