maybe some resistances needed?
A bench power supply may not be the best choice because its power regulation may fight with the current regulation within the stepper drivers. I suggest you set the power supply to a high voltage (subject to the max for the driver, of course) and to a high current and allow the stepper drivers to protect the motors.
My advice is limit the current to 1A, voltage 12V in first instance,
If you mean that you should add some resistors between the power supply and the stepper drivers then NO, definitely not.Tell us why you think "resistance" might be needed....R