You can add a decoder for it, but it won't be a drop-in decoder. You will have to hard-wire one into your locomotive.

After your second post here, I anxiously went to your website excited like an 8yr old on Christmas morning!

New version?!

Use an N scale gauge to test the distance between the wheels and also check the track gauge distance and the points of the switch.

Mine make the same sound.

There is a hobby shop in Milwaukee that I went to a couple of years ago. Not bad. Yes, you can mix other couplers and stuff. However, you cannot mix knuckle couplers (which most, if not all, manufacturers make now) with rapido couplers. They don't work together.

The motor circuit controller on the DCC board is probably shot. You'll either need to install a different decoder or return it for repair for Bachmann.

Bachmann does not sell a separate tender with DCC already installed.

You probably crossed wires creating a short circuit.

When I soldered and installed my Soundtraxx Econami DCC sound decoder into Bachmann GP-7, I desoldered the spring tabs from the stock DCC decoder and then taped them to the chassic. I used all four in case one lost contact with the chassis. I have used mine without fail for about a year now.

I have sound in mine from a TSU-750. It sounds awesome.

No, the radius won't be a problem, and yes, the couplers will work together.

Does it bug anyone else that the train is derailed?

I am excited about this locomotive!

You can easily hardwire a decoder in there because it already has pickups.