I just got a Dynaverb from Rudy's. They were out of sealed stock so I got the floor unit that I auditioned. At the store I didn't really notice any noise because the cab I was playing through had its tweeter down or completely off. When I got home I did a comparison between it and my Holy Grail. Switched off, the EBS is expectedly quiet. When I engage it and don't play, there's a grainy noise akin to dusty vinyl. As I begin to play louder and louder on the bass, the noise is relegated to the backround but it's still there. The noise floor of the Holy Grail OTOH is much better with no audible artifacts with the pedal engaged. I'm beginning to lean on my return/exchange policy. What do you think?