Bachmann SD40-2

[Catweasel]

I have an SD40-2, DCC equipped, which I wish to fit sound to. Is there a board that's a straight swap for the Bachmann board? I know speakers will be a challenge, but I can put a small speaker under the cab roof. Unless anyone has a better solution? Thank you. 

[bapguy]

Looking at the diagram, there might be room for a speaker in the fuel tank or in the indentation in the frame top towards the rear. Soundytaxx has a board style decoder but it is not a plug and play.   Joe
diagram: http://www.bachmanntrains.com/home-usa/dwg/dwgs/H609X_IS001.PDF
Soundytaxx  decoder: 828041
Look at this link for an idea of how to put in the decoder board
http://www.soundtraxx.com/documents/appnotes/bachmann_gp7.pdf

[Catweasel]

There's no room in the fuel tank as it's full of lower chassis weight. There's no room in the body for the same reason. The circuit board of mine has got the yellow LED. I did see in the stores another board with an 8 pin plug. Are they interchangeable I wonder. Make it easier to change the decoder possibly.

[bapguy]

The board with an 8 pin plug are interchangeable. You then buy a sound decoder with an 8 pin wire harness on it. I prefer using a board style like Soundtraxx uses. It's a better install in my opinion.     Joe

[Catweasel]

Lifted the board on the SD40 to have a look underneath. There aren't any ins, it's hardwired in. I'll still have a look round. Rather than mess around replacing the board I'd be inclined to put a normal sound chip in and hardwire that.