Any transformer that puts out a chopped sine wave flow is going to affect this particular locomotive like your Z-750 did.
Not all original Protosounds (there is no MTH official designation called PS1) behave the same when operating with chopped-wave outputs. Most of my first generation Protosounds work with my Lionel BW-80 at home and the Lionel ZW-L at the club. But my MTH Premier Pennsylvania K4 made in 1996 does not. It works fine with my MTH Z-4000.
The same is true of some other early MTH models.
Check the manual for the recommended transformers. You’ll see a lot of postwar Lionel transformers listed, including the big ZW. The MTH Z-4000 also outputs a pure sine wave flow. (The problem with using those older postwar transformers, however, is they generally don’t provide fast enough circuit breakers to protect your modern electronics in locomotives.)
As for those that won’t work, in addition to the MTH Z-750 and the Z-1000 and the Lionel ZW-L, you’ll want to avoid the Lionel CW-80 and really any other Lionel transformer made since 1990, plus the MRC Pure Power transformers.
By the way, I should’ve thought at this problem on the other thread you posted. It completely slipped my mind that your transformer could be the problem.
