Hi Luka,

Now I remember you wrote a message about not better results. Are you sure you did NOT use the new sounds !
In my case I did a full downgrade to OS3.0c and after that followed the instructions on the Ketron webpage. (On a few points the SD1 behaved not as in the manual)

I played (and 'teased') the SD1 and .... NO dropouts in the Bass.

Perhaps you can give it another try ?