Lehmann Black Cube SE ii with EU voltage - step up transformer

Hello all - recently purchased a Black Cube SE ii here on the ’gon and when it arrived, I discovered that it is an EU 240v version and not the US 120v edition I need. I admit I’m annoyed with the seller - this wasn’t made explicit in the listing, only evidenced in one photograph of the box. Given the fact that we had multiple exchanges prior to purchase and he knew my shipping address was in the U.S., well, you’d think he might have mentioned it. But, well... there was one photo among many that I did not think to scrutinize. Another lesson in buyer beware.

Anyway, I am now trying to decide whether to return the unit or use it with a step-up transformer that will take my wall voltage of 120 and convert it to 240. The Cube SE ii draws an MPC of 7w, so it is not a power hungry little bugger at all, and should function fine with a such a device. My question is... will it affect performance? Will I be getting the full effect of the unit? Have any of you used EU 240v devices with such a transformer as a long-term fix and were you happy with that arrangement? Thanks for any input.
I have included the Lehmann web site address below. If you go to the FAQ page you will see where you are able to submit question
(s) to them directly.
I am thinking that they would be able to revise or mod your PWX for 115V 60 Hz and / or send you the necessary parts so you can.

If you look thru there site you will find that they update earlier versions of there product to the latest revision. I would think that revision may also include a change in the input power circuit.

At the least they should be able to answer your question regarding  the use of a step-up x-former.

I have the original B/Cube with the optional Pwr supply, which is now designated the SE model. I am very satisfied with its performance and have never really thought of replacing it.

Best of luck.