I have just had the M1 active soundhole pickup fitted to my Martin HD28VS. I got it home and had some very serious fret buzz happening. I took the pickup out to access the truss rod, so I could do an adjustment, and the fret buzz stopped. The guitar also sounded fuller and sustained better. I put the pickup back and the buzz returned. To the point of choking some notes. Has anyone had this problem and is there a way to alleviate this.
The guitar has a fixed "drop in" long saddle so fitting a piezo pickup may be problematic.