@ doneldon, Thanks for the info. sorry I wasn't clear about how they work. I understand how they work, my request was on how well they work and if there was one supplier that was better than the other. Did very much appreciate your response and your time to do so Thanks

I have a Bachmann Sectrum B&O EM1 2-8-8-4 and a Bachmann Spectrum N&W J 611 4-8-4 and I would like to add smoke units. I have seen some after market units but not sure how they work. any advice would be appreciated.

Thank you, I do have some experience with soldering and basic electronics

I have the Bachman HO Spectrum Cavalier set with the J 4-8-4  611 N&W engine. It has DCC but no sound. I would like to know where I can get the sound decoder/device to add sount to this unit. Any suggestions would be appreciated.