Working function of a Stentorphone Soundbox

The Stentorphone was developed between 1910 and 1920 by Harry Alfred Gaydon. Stentor was a character in Greek mythology who had a very loud voice. The difference between a traditional Gramophone and a Stentorphone is the balanced comb valve instead of the diaphragm. The sound gets amplified thanks to compressed air at a pressure of approximately 0.2bar.
The aim of this project is to restore the original Stentorphone soundbox (which hasn't been used since 1913) and to create a working polymer replica of the sounbox with 3D printing technology.
This animation explains the working function of the polymer Stentorphone soundbox.
Tests were done with the original soundbox, the polymer replica and 2 hybrid models ( polymer replica with 3D metal printed valve and oroginal soundbow ith polymer comb valve).
Link to the video:
• Testing of Original an...

[@GramophonicReevolution]

YT is ag place. I had not heard of these until just now :)

[@ericalbany]

You have the turntable rotating in the wrong direction.