MELGAR, my two MTH RS3s sound similar, but not exactly the same as my RS1. The RS3s don’t have the initial long “running on one cylinder” sound or the “whistle” (probably the turbocharger on the prototype) at idle and when accelerating. The first time I started the RS1, I thought the sound system was bad!
When I was a kid a “couple” of years ago, I used to see an Alco S4 operated by the Grafton and Upton RR. It had the “whistle”. Every time I run the RS1, it reminds me of my youth!