I used the Diesel Decoder as an under the table sound module by replacing the speaker with a headphone jack and adding surround sound speakers. Wow! Awesome sound that gives the impression of being trackside. The power supplied direct from rails with the decoder mounted in a separate box. Simple set up and consisting, sound can be shut down or activated at DCC power on. Decoder has a multitude of sounds for early geeps and switchers, including horns, brakes, bells, etc. I used an NCE DCC system with a mix of decoders.