You can call the audio transformer as one of the key components of an ESL57. The audio transformer includes every single part to get the musicsignal prepared to power the importened electrostatic panels. Each transformer is carefully produced to match the original specs. We deliver the audiotransformer ready to install incl. a metal chassis which includes the bananasockets for the speaker cables. and the resistorboard is added to the transformer. Please note that the shipping costs are calculated for delivery within Germany. As soon as you contact us we will calculate delivery costs to your door.