I have owned ones by monster, niles & russound and they definitely degraded the sound. I have one that was by Tiffany that used expensive connectors, a nice case and a good selector switch and as long as the interconnects are good enough, there is no degradation to the sound. I don't know of anyone currently making a good one besides Manley's relay based Skipjack. It would be nice if there a good one that didn't cost $900 like the Skipjack (although I am sure it is definitely worth it).