Hi, I'm pretty new to building tube amps, and I just got to the glow test of the bottlehead crack. The manual states that I need to insert the tubes into the 9 pin and 8 pin sockets, but the tubes won't fit into the sockets. I checked twice to see if I installed the sockets correctly and I did. Is there a special method not mentioned in the manual to insert the tubes? Is it possible I was sent the wrong tubes or somehow damaged the sockets? Thanks