Dear George: The Azymuth subject is a critical factor to achieve the best from any cartridge due that no one stylus cartridge comes in perfect alignment.
I never mount my KRSP on the MS tonearm because I obtain a near stellar quality sound reproduction on the Lustre one where and through the Lustre headshell you can make Azymuth changes.
Try to find a headshell with Azymuth movement and try it with your Koetsu and maybe you could have an improvement.
Regards and enjoy the music.
Raul.
I never mount my KRSP on the MS tonearm because I obtain a near stellar quality sound reproduction on the Lustre one where and through the Lustre headshell you can make Azymuth changes.
Try to find a headshell with Azymuth movement and try it with your Koetsu and maybe you could have an improvement.
Regards and enjoy the music.
Raul.