I recently purchased a 91803 to replace my 81088 that has a broken front truck. I plan to run it in DC analog and wire it to a Soundtraxx TSU-4400. Does anyone know what types of bulbs are used in the 91803 (12 volt, 1.5 volt, led, etc.) as resistors are required for anything under 12 volt. Also curious if anyone else has connected this combination of products together and if so, do you have any advice or tips?