Tubes in a Shroud

While I was ordering parts from the Parts Connexion I also went ahead and got some upgrades for the tubes. What you are looking at are the 12AU7's in Perl tube coolers. In case you are wondering, yes, they really do remove a lot of heat from the tube itself. Whether that will have any benefit at all in the long run, I have no direct experience.

If you look carefully you'll also see the white of the new sockets peeking out. These are Azuma ceramic sockets with gold plated pins. As far as I know, these were the best sockets I could find which could be made to fit. They come with a gold plated pin in the center. Fortunately a little time with a hand drill and they pop right off, leaving the rest of the socket in perfect condition.
Some Tube-o-philes prefer the brown resin sockets which were original with the preamp. They think it's microphonics are the best, and the contacts are good enough. I looked at the contacts, they looked nasty. I'm sorry, they were going. If I every decide to worry about microphonics, that's what the tube coolers will do.