I think what line 72 says is that the loctal
socket is about 2 euro. But not the adaptor since each adapter requires a socket, pins in a body of some sort, internal wiring and labor.
Another option would be to change out your 6sn7 octal sockets in your amp or pre for loctal ('Locking OCTAL') sockets. If you're handy that would be nice-and-cheap but if Shadowlight is right about 7n7 manufacturers then you've severely limited your rolling capabilities by doing this. Again, it might make sense if you found 7n7 versions of super-expensive 6sn7s. What might be really cool is to make a diy amp/pre with both octal and loctal sockets.......or just get the adaptors!
