The lights have a resistor on the ends that converts 16VDC from light hub to 3VDC. You need a 16VDC max power source into the building to make the lights function properly. If you use a straight 16VDC power source you have no way to dim the lights (ie lower voltage). If you use a DC transformer you run the risk of using too much voltage and burning out the lights. It is best to stick with the light hub and run a 24VDC or 16-20VAC power source to the hub.
If you want to mix WS lights and normal incandescent grain of wheat bulbs (14 to 16VAC/DC in the same building you can purchase a JST to Terminal Screw Connector