I use this unit for 15 days and I am satisfied with TRS. This is a module inserted between a source (eg CD) and an amplifier that allows the rglage the final volume.
I use it in my studio amplified speakers and my NAD CD player. It possde bandwidth and very linear n'altre not sound. The connection is working exclusively in XLR format. The quality of German manufacturing and finishing is remarkable. A handy little device and whose only default is not to possder tlcommande!