I received the new MTH Chicago & Northwestern Train Master (yes, not a misprint; MTH does make TM into 2 words). Nice looking engine, but it exhibited distorted audio due to the shell itself or component in the shell resonating with the speaker audio to produce an annoying vibration. I immediately returned it to the seller, Berwyn's Toys and Trains. Thanks to their cooperation and without any hassle, they promptly resolved the problem by sending me a new engine. All is good! (@gunrunnerjohn explained to me the underlying technical issue with the audio on a few MTH engines and the possible solutions.) I generally just return defective brand-new items back to the seller for refund, exchange or simple repair (rather than me attempting my own repair on a new item!) Again, much appreciation to Berwyn's.