The standard AC SOUND SYSTEM's were designed for the model railroader utilizing the standard conventional Whistle / Bell controller or the LocoMatic™ controller for operation of the Horn, Bell and other sound functions. This system consists of two boards, the AC power board and the sound board. They will automatically adjust the prime mover rpm with changes in motor voltage. Sounds produced are appropriate for the type of unit listed. These systems can be mounted in the engine or car (with track pickups). If mounting in a car, for best results you should have an e-unit connected as well, otherwise the sound system will ramp up and down with track voltage. E-Unit #518 would be ideal for this type of installation. Appropriate speakers can be found on the speaker page.

The RDC New Haven units feature the Hancock Air Whistle found on the New Haven RR. Standard RDC units are equipped with a single chime horn as equipped from the factory. Many railroads changed these horns after delivery or use over a period of years.