Hi @5StarNomad @josepailo, thanks for both of your help. I tuned the saw module with the tiny screw. Now all te octaves play in tune, wich is really satisfying to listen to, when the PO170 is in combination with any melodic sequences from the op-z and op-1. I didn‘t touch the filter screws yet.
What I‘m experiencing now is a fluctuation sending cv from the oblap module. Maybe this is a result of the nearly empty battery.