Voja,
I think you are seriously missing the point. The big problem with the transformer box is potential SAFETY issues. When spritzer talks about the construction not being up to code, what he is talking about is construction standards that are designed to protect the user from being SHOCKED, or worse, ELECTROCUTED. For example, he mentions that the XLR connectors are not spec'd for the voltages they are intended to carry, which is not aa good thing. The metal panels on the box are not all connected to ground which means that if a wire inside the box should somehow break and touch an ungrounded panel, and you then touch that panel, you would get a shock. That is why all modern appliances (including amps) with metal boxes have their outsides electrically connected to the ground wire on your three wire power cord, for your protection. You admit that you are not a technical person, so you should pay attention to someone like spritzer, who is. It doesn't matter a bit if the headphones sound absolutely perfect, if they could injure or kill you. End of discussion.