Spirit System

I've tried Delay of 0-4 and Dynamic of 6 as std and it's the same. With power off it's smooth but with power on and a finger behind the horn it as rough as.... Tried an old DS 95i and that's Ok.Replacement servo time. Thanks.

You are welcome.
The original servo should behave in the same way when you will connect it somewhere else. If so then it would be absolutely clear.