Walthers Proto GP20

There isn’t a lot of space in this loco for a sound installation. Not an installation for a beginner. Best done with a milling machine.


I milled off the rear light surround from the weight. The speaker was mounted using a 1.6x5mm metric screw with caulking sealing it to the weight. Before the seal caulk was installed, I ran the rear truck wires through a piece of heat shrink tubing between the speaker and the weight.

I used 12 volt LEDs to save space. The black cap that was over the rear LED was used over the front LED, held down with Kapton tape. The black cap over the wires was installed after this photo.

The TSU-2200 was installed with all of the connections made in the area in front of the decoder. If one wanted more room, the entire upper portion of the weight between the cab and the rear could be milled off and have more room.

TURN THE VOLUME DOWN. Somewhere between 75 and 100 is fine for the overall volume, perhaps less. This decoder puts out 2 watts and the speaker is only rated for one. No need for high volume settings and they may damage the speaker or decoder. To be truly safe, a 10 ohm 1 watt resistor could be added in series with the speaker. It will get warm, so finding room for it would add to the complexity of the installation.

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