The installation of a Bell U.S. telephone centre is probably one of the greatest technological achievement of Candé. It was connected directly to the centre of Tours and the only device of its kind in a private residence in France. During the time of Jacques Drake, telephone connections were made via an employee of the post office in Monts, who did not provide the service on an ongoing basis.
The branch exchange that provided connections between the calling station and the called station, the energy panel and the battery, which provided an available source of energy to power the branch exchange and the telephones, were set up in the basement of the castle. Therefore, it was possible to call someone on the other side of the world or in the castle from each room. An operator managed the switchboard at all times.