Without pictures, it's very difficult to really see what's going on. I've had many Slingerland snares, and clones, using the Zoomatic. Each has worked flawlessly and provided excellent range to go from a loose "fat back" sound to a tighter "choked" sound. The Zoomatic needs to be in good physical condition and you need to know where to set the initial adjustment. The attached picture is a Buddy Rich 4x14 custom built snare drum. Due to the way the Zoomatic is installed, it needs more attention to initial setup. I'm able to get many snare wire tensions even with the limited range of the Zoomatic on this drum. Just my :2Cents:
-Mark