Is a 21 pin DCC decoder better than an 8-pin decoder?

Surely more is always better, so a 21 pin decoder is bound to be better than an 8 pin decoder? Actually, the answer is not that straightforward.

With more pins, a 21 pin DCC decoder will be able to manage more functions than an 8 pin decoder. Functions can be anything but are usually lights or similar. An 8 pin decoder will be able to control up to 3 functions while a 21 pin decoder can do 6 functions as well as a speaker and stay alive capabilities.

So, if you want sound, you need a 21 pin decoder.

If you do not want sound, an 8 pin decoder is likely to be enough for your needs.

Bear in mind the choice may not even be yours if you do not want to hardwire and solder the decoder: the decision will be made by the socket inside the engine.