Well, I finally have my 5f6a built, but I ran into an unexpected problem. I can't get the preamp and PI tubes in the sockets. I've applied moderate force, but I don't want a glass tube shattering in my hands. These are Belton sockets, by the way. I really tried not to let solder flow where it shouldn't, and I soldered the connections with the sockets oriented horizontally. Is it possible that these sockets are super tight or do you think solder has mucked them up? The holes are too small to see what is going on. I just bought some noval socket savers and I'm hoping that I can force those into the socket to loosen it up. Does anybody have any tricks or tips? I don't relish the thought of replacing those sockets! Thanks!