Adding sound to DCC equipped Bachmann GP40 Diesel, and DCC Wiring question

[mveleza]

I just got an HO GP40 Diesel Loco- DCC Equipped Union Pacific and it runs great.  It has lights and will run on DC or DCC.  Can Sound be added to these already DCC equipped Locomotives from Bachmann or must the current decoder for DCC be switched out?  How if so?  I'd love to hear from anyone that has added sound to one of the Bachmann DCC equipped locos since I own three of them now and none of them have sound, only lights.

On a separate issue I'm building my tabletop layout and was wondering what people are using to wire their DCC layouts...I have 16 gauge and 18 gauge wire at the moment and was thinking of using the 18 to distribute power around the layout with the 16 serving as feeders to track sections.  Is DCC wiring a lot different from DC since you don't need power districts?  I don't notice much drop in train speeds on my layout...do I even need feeders and a bus?  My layout is 4 x 7 and consists of a pasing lane and odd shaped oval with an internal oval running seperately on DC.  Any thoughts and comments would be appreciated .

[mveleza]

BUMP comm on someone has to know how to get this done 

[the Bach-man]

Dear M,
You'll have to hard wire a sound decoder to the board, and, presumably, remove the built-in decoder from the circuit. I'd suggest getting help from an advanced DCC modeler.
Have fun!
the Bach-man

[BigBob1]

For a layout the size of yours, #16 wire should be fine. You should only require heavier wire if you're running two or three 4 & 5-unit consists all at once & long heavy trains. I have an 8 X 14 around-the-room layout with std. & narrow gage & I only have one 16 ga. track feeder on each line. Make sure you have good track joints & make good solder connections whenever possible.  After running for a while check for any wiring getting warm. If it isn't, you're in business.

Bob Battles