Schnellar-style timpani (developed by Hans Schnellar) have been used by the Royal Concertgebouw Orchestra in Amsterdam for decades, and their special design has been released by Adams - and upgraded with modern innovations - to the rest of the world.
When most timpani are tuned, the process is very similar to the tuning method used on snare drums, toms, and many other drums: the tension rods pull the rim down onto the head. Schnellar timpani are very different in this regard - on these instruments, the bowl moves up against the head, while the rods and rim remain stationary.
Adams has retained the majestic quality of this 25" drum with several high-end features: