I bought one of the “Ground Boxes” last year and like what I does for and in my system. The Ground Control from Computer Audio Design (CAD) is connected to the ground post on my SuperNait2 and the barrel of one of the unused S/PDIF inputs on the NDAC. The glare that plagued my system for several years is gone and I can listen for several hours without fatigue. While the sound is smoother, it has retained its dynamic range. The system is fed by an Igel Plus, they are clearly compatible.