Saxophone repairman Matt Stohrer of http://www.StohrerMusic.com knew you’d be asking for a sound sample of the Conn 10M Prototype, so here you go. I had just overhauled this sax for another client who gave me permission to have Branford playtest it. You can see and hear him starting to get used to it and have some fun by around the 2 minute mark.
For whatever its worth, the horn in this video is one of the better ones that I have ever played, and it basically plays very, very much like a good pre-war 10M, even with the weird neck.
Quick Repairman’s Overview of the weird neck: https://www.youtube.com/watch?v=dNFvOcH6DXc
Proper Repairman’s Overview of the 10M Prototype: (coming soon)
If you like this stuff, consider supporting me on Patreon: https://www.patreon.com/mattstohrer
Also check out the Open Source Saxophone Project: http://www.OpenSourceSaxophoneProject.com