Transformer question--need transformer that puts out nominal 240V for European Amplifier

Maybe some European members who have moved to the US know the answer to this.

I bought a European Amp to use in the US. Many Euro amps work on US 240 but this one has a phase protection circuit and it won’t work on US 240. (the difference is that US 240 is 2 legs of 120v out of phase so that they are 240V relative to each other. The Euro system is one hot let of 240V and a neutral leg of 0 V or ground).

So I bought a cheap but sizable (3000W) step up transformer off amazon to test it with before I shop for a quality transformer and very surprisingly it creates US system 240 (2 legs of 120V). You might think this is not surprising except it is marketed to run EU equipment and even has EU style plugs. I don’t even know how they do the phase shift. A simple 2x voltage transformer (often called autotransformer) would create 240 EU standard.

So my question is does anyone know how to select a transformer that takes 120V US and converts it to 240V EU standard?

Thanks,

Jerry