I just made an observation that you don't necessarily have to have current top-of-the-line electronics to hear the audible difference(improvement) with the SR Black fuse. In my bedroom system, I have a 1960 Pilot 402 tube receiver and taking out the cheap glass fuse(AC fuse) and replacing it with the SR Black fuse made an enormous improvement. Of course, I have excellent cables and older Reference 3a Master Control speakers but these better cables and high-rez speakers only made it more obvious with the improvements given by the SR Black fuse...pretty impressive.