Installation Notebook:
Sound installed in a Stewart FTB Diesel
Start by disassembling everything from the frame. Use a belt sander to knock off a few high spots so that the speakers can mount flat. Glue down the speakers with RVT or Goo.
Disassemble the trucks and solder Wire2951 to the tabs. Reassemble the trucks.

Bruce then built a platform 1 inch wide out of 0.04 styrene which extended from the magnet of the front speaker to the rear of the loco. The platform was secured to the speaker magnets with double sided tape. The stock coupling capacitor (33 uF) was discarded and a 470 uF 16 volt bipolar substituted. The capacitor was connected between the + and - terminals of the two speakers (not shown above).
The Keep-Alive Capacitor was wired to the DSX using some of the red and black track pick up wires. CLICK HERE for details. The DSX was secured to the platform with double sided tape.
The DSX was wired to the truck wires and the speakers (see the purple connections above).
After tweaking a few CVs, the loco was off and running.
Speaker Mounting
Two speakers are used to give better sound. The shell is the enclosure
- almost no sound will be heard until the shell is in place. The speakers
are glued to the frame to seal them. The two speakers are wired in
series (+ to -) to provide a 16 ohm load for the DSX.
Here is the wiring diagram:
