Okay, just for laughs...
I put the #33 on the bench and hooked up a volt meter to the leads of a Lionel type S transformer: it started in at about 6V and by 10V it was running about as fast as I'd want it to. (Interestingly enough, its performance is almost identical to a 1946 vintage S scale American Flyer #320 Hudson. I know this, because I checked. )
The #10 didn't start to run until 9V; by 12V it was running as fast as needed; which is to say, fast enough.
In lieu of a video, I figured this would be the next best thing...
Mark in Oregon