I have the Conn 25i Euphonium that I had restored (as much as possible). When I bought it, I did not pay attention to the valve springs. I noticed on my Besson that it took some effort to depress the valves, so I got Medium Meade springs and it was easier. The Conn also takes an effort compared to the Besson. I just do not know what types of springs might fit the Conn. Does anyone have a Conn 24i/25i and had this situation? Just need to know what springs I might get (or just do more finger exercises)!