I picked up the new MRC N Brilliance Steam 0001637 decoder and found it will fit in a Z Scale USRA tender. Also fit inside was a 3/8" speaker and 2 D size Tantalum Caps: I did not use the headlight functions, just motor and power. It all packs inside the tender just fine: Drilling holes for the 3/8" speaker did not make the load look too ugly, but I can doctor it up a bit with real coal to help hide the holes: It still resets too easy, which stops the train and resets the sound, so i need to do some more work yet.
Actually the speaker is louder and clearer than the 17mm one that came with the decoder. It also came sealed in a metal enclosure, which is extra $ from the DCC shops. It's a 10mm cell phone speaker for the new generation of musical phones. I found it on a google search for 3/8" speakers, as some surplus place for 49 cents. Beats $8 for the speaker and another $5 for the enclosure from one of the DCC hobby shops!
