okay, basic info: 120 Watt Peavey JSX head Came with Electro-Harmonix EL34's stock. The tubes needed to be changed so I bought JJ/Tesla 6L6's. Switched the small switch inside the amp to the 6L6 position, and installed my new JJ's. Problem #1 One of the tubes is not seating properly....we will call this "tube a". Tube A, when looking at the BACK OF THE AMP is all the way to the left. There is a very noticeable gap, and I am afraid to press it down anymore because I'm afraid I will damage one of the pins. #2 Biasing I have never done this before in my life...and I'm not super technically inclined. I don't have a clue of what my Plate Voltage of my amp is. I don't know what the Cathode or plate voltages of the tubes are. And every sight I have looked at stress not to go by the bias points (place to insert your leads from volt meter) that are on the amp. SO DEAR LORD WHAT DO I DO???? the tubes say their bias point is at 20. I have a simple volt meter, and I have it set to the 20K position on the ohm side...(i don't even know if that is where I should have it). Every site I visit is giving different info about what the amp should be biased at. A common message that I"m reading is that Peavey Bias the amps too cold. ****there is a small bias pot used to set the bias....so if my volt meter settings are right (meter set at 20K on the Ohms section)...what should the bias point be? And how does some one get a number like 42 ma or 50ma...please break this down in terms that a 2 year old will understand it.