I have used Digitrax, SoundTraxx and TCS and have bought a few Bachmann Sound Equipped Locomotives with whatever sound decoders they have used. I want to know what Diesel Sound Decoders you guys have used and why you like them. For Steam Sound, I think TCS Sound Decoders sound very good. I also like SoundTraxx for steam. I've found whatever Decoders Bachmann has used to simply be O.K.; however, the diesel decoders they install mostly sound like metal grinding and not an engine running! So, do you have opinions?