This installation is for a HO-Scale Atlas GP-7 using a TCS WOW121-Diesel Decoder, AK-MB1 and
UNIV SH4-C WOWSpeaker kit by TCS.

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:

These items are available in the WDK-ATL-2 which was used for this installation.
AK-MB1 Motherboard with Keep Alive™ WOW121-Diesel Decoder UNIV-SH4-C Speaker Kit
Click here for more information on the WDK-ATL-2 and the rest of the WOWDiesel Kits line.

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

The Atlas GP-7 shown with the shell on. To remove the shell, first loosen the railing on each side of the cab then gently squeeze the shell on
either side and lift it up.

Shown with the shell off. Clip the track leads and loosen the metal motor connection tabs to be able to remove the original lighting board.
Discard this board along with the attached light.

Shown with the original lighting board removed.

Using cutters, shorten the metal motor lead tabs and solder a new connection point to them.

With the solder connections in place, solder new leads to the motor, insulating the connections. Trim, lengthen and tin the wires to the track leads as necessary.

Attach the AK-MB1 and solder the track and motor leads to it.


To next install the lights, remove the light assemblies from each end of the shell. Trim the front and rear light tubes as shown above.
The front right behind the vertical partition, the rear right in front of the wing.


Next we installed new 3mm Sunny White LED's (Item 1288) to these trimmed tubes using a small amount of hot melt glue, adding
and insulating wire leads onto them. In this installation, we routed out the front light tube to allow the LED to mount flush into the tube.
You can also use surface mount LED's.

We have found that LED light output is brightest when shinning directly into the end of the light tube, but in some circumstances they may be placed along the length
of the tube as well with satisfactory results. In doing so, white light LED output would be least affected, while non white LED output will be more affected by placement.

After the lighting is in place, insert the 25mm x 14mm speaker into the UNIV SH4-C housing and using hot melt glue, attach this to the
top of the shell as shown.

If your speaker enclosure installation covers the portholes on the enclosure, we recommend adding new port hole(s) similar to the original porting. Be sure that the new portholes are the same size and amount of the original and are vented freely into the locomotive We have found introducing a port of the correct size greatly increases the volume and sound quality of the installation. Too much or too little porting decreases the sound quality.

With the lighting and speaker in place in the shell, solder these wire leads to the AK-MB1 according to your included wiring diagram.

You can 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 Atlas GP-7 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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