The following pics show how I installed a Soundtraxx DSD-AT100LC sound decoder in my Kato SD70MAC. This if for those model railroaders who may be skittish about dremeling holes in their favorite loco to make room for sound. For the SD70Mac, the cab was the likely choice for speaker location. It required some cutting of the dash inside the cab to fit the speaker and two small holes drilled with a small pin drill for the speaker wires to travel through. I also removed the rear windows in the cab for better sound. This is the first time I used a speaker enclosure and I must say it does make a HUGE difference in both sound loudness and clarity. USE AN ENCLOSURE IF AT ALL POSSIBLE!
The only problem I had was that I reversed the 5 & 6 track polarity and had to resolder them again. Also use a 1k resistor at pin 8 (common function) rear light and also pin 3 (common function) front light.
Here is a wide shot of the tools and workbench used to add the sound decoder
The “LC” nomenclature stands for low cost, but don’t let that fool you. This is one awesome sounding locomotive. It also gives you 3 choices of chimes for your horn. All in all I find it well worth the cost to add sound to a favorite loco. I spent about $60 total for the decoder, speaker and enclosure. “Tonys Train Exchange” is now a regular stop for me.
Thanks a lot for sharing, this will come in handy if I ever decide to try sound. $60 is great! I’ll have to give Tony’s trains a try. What kind of soldering iron did you use?
I use a rechargeable “ISO tip” soldering iron. It uses a small needle tip for the point and works great. Its about $45, but well worth the cost. It heats up almost instantaneously and comes with a light to help you see.
I have been thinking about putting sound in my kato SD70 for a while. How noticeable is that speaker/enclosure inside the cab? I mean, does it attract your attention or is it not really a big deal?
P.S. I also have that soldering iron. Its great, if you are looking for a cordless iron that is the one to get.
Its not noticable at all. There is no light eminating from the cab so you really dont see it. It sits between the engineers chairs. I too thought it may be distracting, but its not. If the speaker was a bright neon green, then yea maybe, but its black and blends into the cab quite nicely. If you want I can post a pic with it complete to give you and idea.
