Marklin mSD SoundDecoder. Gauge: H0. This decoder is for converting Marklin/Trix H0 locomotives with built-in high-efficiency motors or other DC motors. The marklin mSD SoundDecoder has a wiring harness soldered to it. This wiring harness has an eight-pin NEM connector plug for converting many locomotives with a corresponding NEM connector and locomotives without much space. The marklin mSD SoundDecoder supports the digital formats mfx, MM 1, MM2, and DCC. The decoder has preset sound for a steam locomotive.