Is that whine electronic sound or the actual fan motors?Those are nice looking locos. I have an Alco PA1 AA pair so I know that photos don’t do the plated finish justice. I also have an MTH SD40 (RBMN). I like the looks, but I couldn’t agree more about the sound. Due to the annoying blower whine, it doesn’t get much run time.
On Lionel Legacy engines you can turn down the prime mover sound in relation to the rest of the sound effects. I don't know if this feature is available with MTH.It's turbo/super charger whine. I have a few MTH locos (SD40, SD35, F7) that have way too much and it can get very annoying. I think the sound files are from actual locos and at least part of the problem is that the small speakers tend to do a better job with the high frequency blower sound than they do with the low frequency diesel rumble..