Upscale's comment about covers it. OTOH, for a couple of bucks, you can pick up three "O" rings for each tube at your local Home Depot. Get 'em slightly undersized and slip 'em on. Vary the number and position and listen. I've found them effective, sometimes not. As for Hats, Pearls and Sox, I've tried them all with varying or no success and, frankly, I don't think they're worth the expense. As for Herbie's, no experience with them, but they look interesting.
recommendations for tube dampers???
I have found a combination of components that I think I can live with for a while. So now I'm starting to think about tweaks. I was hoping to get some feedback on various tube dampers that you have tried. The ones on http://www.vintagetubeservices.com/ look interesting, but many things do. Top hats, tube sox, pearl coolers, etc??? Anything you would recommend?