NuTone Intercom Photo Gallery > NuTone Model 470 Amplifier > NuTone 470 Amplifier Terminals
In the center of the 470's circuit board are the wiring terminals. NuTone provided a cutout in the center of the board, which made it easy to bring in the cables for the remote speakers.
This is a fairly tight and compact area, so neatness counts when making all of the connections. If there were more than 2 or 3 wires for each terminal, it would be best to bundle then together in a "pigtail" and put a single wire under each terminal.
Even though the 470 is a simple design, it does include a "chime" input. You could choose 1 of 4 different NuTone "electronic" door chimes that would work with the system. These "electronic" chimes were basically standard NuTone mechanical chimes with electronic pickups added. The pickups would sense the vibrations of the tone bars and send those vibrations to the amplifier.