I just got this unit for the last 2-3 weeks. It’s been an eye opener for me. This Ultra Bank is what the manufacturer calls an auto transformer. It’s beyond me. From what little I know, it seems to ensure that current supply will be optimized. It did make a very obvious difference in my system. In short the system sounded like it’s energized. Bass is bolder and more taut. Mids have better density. Found the highs to be smoother too. Thus the soundstage becomes more vivid. Listening experience is a lot better. It’s been most interesting for me. I used to wonder why it would make any difference bearing in mind from the wall there’s more than enough current to kill a few horses. Something new to be learnt each day I guess. Specifications are here: FRANK ACOUSTICS: FRANK PB-15000Ws Power Bank Storage ps I’m not the manufacturer or a distributor for this component.