Complete upgrade with command and sounds by Soundtraxx. Still adding resistors to all the lights, only the headlight is done so far.
I don't like to run the sound at full blast, so you may have to turn up your speakers!
I used the Tsunami TSU-4400 ALCO decoder and I must say this is some of the best sounds I've heard in my toy trains! There are 9 prime movers, 40 horns, and 18 bells to choose from, over 50 sound effects can be used! This was about half the cost of ERR command and sound upgrade. I had bought the DCC system to use with my garden trains and decided to try it in O gauge, I think I will be converting over to DCC. One remote for all my trains!