I run DC, so a Quantum Engineer seems like the way to go if I want to get the most out of a sound-equipped loco. My confusion is…there appears to be a separate Quantum Engineer for each brand of locomotive. I thought that the Quantum Engineer was universal and worked with any QSI-equipped loco. But in Walthers they specifically show a Quantum Engineer for P2K locos with the P2K logo on the unit. And further back there is a different Quantum Engineer for Broadway Limited locos, and the price is different for this one! And my local hobby shop carries yet another one with the Atlas logo on it and the package says “for Gold Series locos”. Unfortunately, my local hobby shop guy was clueless as to why (you would think he would know what he is selling). So what is the story with this?
Before I went DCC, I bought first the Bway Ltd Horn/Bell pushbuttons, Then the Atlas Quantum Engineer. Neither worked on my Lionel Turbine or Athern Challenger. It looks to me like you have to get 3 or more to make all your units work! DCC is now as low as $129.98 (Walthers Jan sale catalog) for the Prodigy Express - you’d probably spend more than that for 2 or 3 DC sound control units.
The Quantum Engineer sold by Walthers with a P2K logo is the same as the Quantum Engineer sold by Atlas with an Atlas logo and the Quantum Engineer sold by BLI with the BLI logo.
The earliest BLI locos can’t use all functions of the Quantum Engineer. QSI switched to a firmware version in the decoder that fully works witht he Quantum Engineer about the time the Atlas Trainmaster came out. Anything built since then, plus any fitted with the upgrade chips, can use the Quantum Engineer. It will control the horn/whistle and bell on older QSI decoders, you just can’t do the fancy programming (basically it can do on the old ones what the old whistle/bell controller did).
–Randy