IMO it’s better to use the step down than replace the stock PSU. For one it should be cheaper and that way you don’t put unnecessary extra voltage on the monitor too, even though it’s within tolerance. At a minimum without the step down it will run a bit warmer and at worst it could reduce the life of the tube.Go figure. I got the thumbs up from Mike to run MS9s on 120v with no issue, but I didn't realize the stock PSU can't handle it. I already went to the trouble of removing my internal stepdown transformers. I think I'll just ditch the stock PSUs and switch to Meanwells or something.