The online hang for all things Sonor
https://drumandstage.com/Forum/
From Maxwells description-
“These sets are rare, especially in such excellent condition. Sonor shells were thicker than Ludwig’s Vistalite shells from this same era. Sonor shells were 6mm.
These drums would have a drier sound and more projection, which is what you get with a thicker shell. Also, the shells are structurally strong. On the 70s Vistalite shells you often get cracks at pressure points such as tom leg mounts, spur brackets and tom holder plates. This is not the case with the thicker Sonor shell.
I just finished recording a video with this set. Seriously killer tone.“