Your Bachmann/Spectrum engine has a Lenz basic decoder in it from the factory. The sound equipped Bachmann/Spectrum engines have a Soundtraxx Tsunami decoder factory installed. You cannot install a Digitrax 'Soundbug' to the Lenz decoder. You need a Digitrax DH165 series decoder that allows the 'Soundbug' to be attached. Your options are to replace the Lenz decoder(a good idea) with a sound/motor control decoder from Digitrax/Soundtraxx/ESU/MRC/Etc... or keep the Lenz decoder and get a MRC steam sound only 'Sounder' decoder(includes the speaker) and wire it to the electrical rail pickups in the engine/tender. I would go with the 1st option, as the motor control in something like the Tsunami is much better than anything that the Lenz decoder has(or a MRC sound/motor decoder).
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
To Rich: Hearty thanks for your tips and references! You are right about Bachmann documentation. I wasted an hour on Googles yesterday trying to get any information at all from Bachmann; even the web address listed on their own skimpy paperwork no longer exists. Your suggested links are good. If swapping out a sound decoder to a DCC socket is an option, I think I can handle the speaker part in a fair-sized tender. In all, I have jerry-rigged over a dozen speakers into old locos, but I have lost interest in soldering up to a dozen 30 gauge wires for decoders. Cheers for this great hobby and guys like you. Bob B.
Plugging in a decoder will be no trouble. Installing a speaker will be a different story. There is no "easy" or "best" that I know of.
Spectrum 2-10-2 diagram which you probably have. There should be paperwork that came with your loco My Spectrum locos all came with paperwork.
http://www.bachmanntrains.com/home-usa/dwg/dwgs/H833X-IS001.PDF
If you have a sound 2-10-2, this is what the tender looks like.
http://www.bachmanntrains.com/home-usa/dwg/dwgs/H838X-IS001.PDF
You can see the difference in the tender frames. I have seen a 2-10-2 sound installation in a Yahoo group but you have to join to see the PDF file of the installation. Not for the faint of heart.
http://groups.yahoo.com/group/RPMclinics-RickBell/
The owner of the list has an online DCC shop.
The SoundTraxx Tsunami decoders are good. Don't know about other brands as I only use the Tsunami.
Here is a link to the Yahoo SoundTraxx Group and there are some DCC online company owners in the group if you decide on the Tsunami.
http://groups.yahoo.com/group/soundtraxx/?yguid=44628248
Realize that with groups that specialize, you might get more detailed explanations.
"Please note, the two loco diagrams are from the Bachmann site and Bachmann labels them 2-10-2 diagrams. Go figure. Bachmann has always been rather poor when it comes to documentation."
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Happy New Year to all railroad modelers! What would be the easiest way to add DCC sound to a new Bachmann Spectrum HO 2-10-2 steam loco that has a motor/light decoder factory-installed, apparently in the tender? Add a Digitrax Sound Bug? Swap out a Soundtraxx board? Some other brand decoder? I have stopped doing any wired-installations, and would surely appreciate any pictures or description of the Bachmann setup inside the tender, before I try to open and modify it for a speaker. Advanced thanks for any experienced help with this prospective project.