The DCC ready, Proto 2000 S1, Alco Switchers may blow DCC decoders that are either plugged into the NMRA socket or hardwired. Although the trucks are isolated from the frame and thereby the frame is isolated from track power, the positive motor connection is tied to the frame at the bottom motor brush area.
In the event that the loco de-rails and the truck/wheels come in contact with the frame, track power will go through the frame and short to the bottom motor brush, which will most likely destroy or damage the decoder.
The solution is to isolate the bottom motor brush from the frame using an insulator and connect the decoder orange from the DCC NMRA socket bd directly to the bottom motor brush. We are looking at several simple options to remedy the problem and will post details soon.
We do not view this as a reason not to buy or use the S1. Consistent with the Proto 2000 tradition, this is an excellent locomotive.