Ian, I can't say for 100% sure, but Soundtrax decoders do not support DC operation. I have used mostly the DSD150 series, also the drop in for the Bachmann 2-8-0. These do not. I'm pretty sure their sound only decoders do not support Dc either. They should be coming out with new full featured decoders soon, as the DSD150 line is no longer available. Perhaps the new ones will support DC, I think Soundtrax needs to compete with the Quantum decoders featured in Broadway ltd. locos. Too bad the Quantum units aren't available seperately. Sure would like to see some competition out there.