If you've installed a DCC sound decoder in a loco before, then its easy. The smaller soundtraxx Tsunami will fit, with a speaker in the tender. If you want easy, solder it to the Bachmann circuit board. Nothing extra needed. I would suggest removing the board and soldering directly to the wires; however, you will have to track them back to find which goes where and does what and to add resistors for the headlights.

The TCS sound decoder will also fit, sounds MUCH better and you can even fit a small Stay Alive under the frame. You can find a "how to" here: http://www.railroad-line.com/forum/topic.asp?TOPIC_ID=31112. Its about half way through the thread.


Cheers!

Brian