I recently bought a pair of supposedly new Amperex 3-400z type tubes. Do these type require more drive than Eimacs? I have tried them and they seem to have about the same output but take more drive and grid current to produce it. Also the idling current is less than Eimacs. Sorry if this has been covered before, I just subscribed to the list. Thanks 73 Merv K9FD/KH6