I just received a new Bachmann Spectrum 4-4-0 with DCC and it is quite a locomotive. It definitely looks better than the new Roundhouse 4-4-0. I bought the unlettered version with wood cab. The loco comes with three tender options, wood, coal, oil. There are three different pilots. I guess to keep the price down, Bachmann did not include sound. I did notice the bottom of the tender is ready to accept a speaker so I am going to be looking at what kind of modification to get sound, DCC/sound module or just sound module. The Big E show comes up the 27th & 28th this month and I know Bachmann will be represented.
I have opened the tender and here is what I have found so far. There are two Phillips head screws at the front and two catches that stick into the tender frame at the rear. The inside of the tender is about 1.06 inches wide. There is a pc board inside with two RF chokes, 4 smt diodes, 6 smt resistors and 3 smt capacitors. The "Bachmann" decoder plugs into this circuit board with the NMRA plug. I suspect the circuit board is for constant lighting, but only the engine light when using the "DC" plug option. There is no light on the tender, though one could be added. The wiring from the circuit board goes out to the front of the tender to plug (one connector, two pins, one connector 4 pins) into the connectors on the engine. The circuit board is 1.055 inches wide X
1.7 inches long. It is mounted about 0.25 inches above the speaker holes. I guess it is called a "noisy" decoder because it operates at a lower frequency. Maybe a little motor noise. It looks like I will install the SoundTraxx DSD-100LC generic DCC/sound decoder. It seems to be the best price, thopugh not as many options. $39.95 from Tony's A 1 inch OD, 0.25 inch high speaker will work out just fine. I just have to figure out how to baffle the speaker.