Just got a decent used "Protosound-1" (as we unofficially say) UP 3-unit "Super Turbine" - the 8500-hp version; cab #5. It runs (first time I have run something in conventional - and using my Powermaster - in so, so long) as well as...PS1 (QSI) runs. It cries out for ERR Cruise Commander and RS. The PS1 "turbine sound" is pretty much just white noise. 4 motors - yessir.
The loco is beautiful, but all those cast-in grab irons and the bright, bare bulb in the cab really date the piece. It's 1996 all over again. I find the detailing to be acceptable, however, and lighting can be modified to a more subtle scheme - the headlight is burned out, anyway. (This thing was $999 in 1996 - really; I paid about a quarter of that - and in little 2016 dollars.)
So - if I ever get there - ERR Cruise Commander is in order...and I mentioned Railsounds. Problem is, there are no gas turbine RS available from ERR...but there is a steam turbine chip to be had. I listened to it online. Now, turbines make very similar sounds regardless of what hot gasses are being exhausted, and if I stay away from the "horn" (it's a steam whistle) it would be plausible.
One day. These are weighty matters in our little world.
(If MTH ever decides to re-visit this loco in the current era, some - not a lot - of re-tooling would be needing to get a real price for it; I don't really mind the cast-in grab irons, for example, but many out there do - unless they want to offer the biggest RailKing Scale loco yet.)