Living in Germany years ago we bought a digital piano with powered studio monitor speakers, both 220V only. It was an old but quality pro level instrument, a Yamaha P500.
Back in the US we used it on an air conditioner outlet, but 15 years later the sound output fails - speaker and headphones - after working briefly. I haven't had it open, but it is probably 30 plus years old.
My question is the powered monitors; might not be able to save the piano. Any chance a conversion is easy? They are ESI, 100 W.