This installation is for a HO-Scale Scaletrains EMD-SD40-2 using a TCS WOW121-Diesel Decoder, AK-MB1 V2 Motherboard with built in Keep Alive®
and UNIV-SH1-C WOWSpeaker.

This was performed by our friends from DCC Xpress installations.
They offer high quality WOWSound installations for a flat rate complete with free return shipping!
You can find them at:

Kit Coming Soon! We are in the process of assembling all the items shown here into a new WOWKit.
Please check back here to see the new WOWKit when it arrives.

Important Soldering Tip:
Please do not use any flux either liquid or paste on the mother board. It will damage it. Use only Rosin core solder approved for electronics use.
We recommend to use only Kester "44" rosin core, SN63PB37, .015" diameter, part number 24-6337-0007.
This can be ordered from Techni-Tool under Techni-Tool part number 488SO157

HO-Scale Scaletrains EMD-SD40-2 shown prior to installation.


    To start off this install, we must first remove the front and rear coupler screws highlighted above and their housings.

With the couplers removed, while gently pulling outwards at each end and along each side of the frame, lift the shell off of the frame.
Take care to release the handrails as you lift off the shell so they don't break.

The Scaletrains EMD-SD40-2 shown with the shell off. Remove the two screws highlighted above in red as well as the wires from the original lighting board and
remove it from the chassis.

With the original lighting board removed, trim, tin or lengthen the wires as necessary.


Remove the two screws highlighted above in red from the front right and left rear side of the frame. This will allow you to separate the top of the frame
from the bottom and gain access to the speaker enclosure inside.


With the frame separated, you can see the accommodation for the speaker inside the top of the rear. Insert the 35mm x 16mm WOWSound speaker into the frame facing
in and using M1.6 screws, attach the speaker to the frame. Feed the speaker wire leads up through the frame, following the path of the rear track pickup wires.

Reattach the two frame pieces with the speaker inside. Using double sided foam tape, attach the AK-MB1 V2 to the frame as shown above.

With the frame reassembled, solder the motor, track pickup, speaker and LED lighting leads to the motherboard according the included wiring diagram and the functions
you desire for lighting operations. Using small lengths of TCS 3/32" and 3/64" shrink tubing, insulate these solder leads.

TCS motherboards include on board current limit resistors for LED use. There is no need to apply external resistors for LED use. 

You can now plug in your WOW121 decoder.

Lastly, in order to keep the wires neat and prevent possible shorts, lace the wires into a bundle using lacing cord, which is a wax impregnated string 
used for wire bundling and making harnesses. There are many choices of lacing cord available from Digikey
We use part number 802534B BK032-ND

Now you can close up the locomotive and reinstall the coupler assemblies. Be sure to be mindful of wire routing and reassembly of the shell as to not damage 
or foul the installation. Your Scaletrains EMD-SD40-2 is now WOWSound equipped and ready to roll!

Other solder tips: When stripping wire, only strip a tiny little bit of the insulation. Strip no more then a 1/64 of an inch. When the wire gets tinned with solder the insulation will shrink back more. Try to not expose any more wire then half the length of the solder pad at most. In no case should solder or exposed wire wire ever be outside the boundary of the the solder pad you are attaching a wire to.
Click here for important information on properly Stripping and Tinning wire

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