Tube Pins

Here at below we can see a ECC81 or 12AT7 tube pins

12AT7 has two amplification section in it. Start from pin 1, that is the anode/plate of the first device. Pin 2 is the grid where the audio signal goes into and pin 3 is the cathode. Together it form one amplification. Another section will be pin 6, 7 and 8.

Then you will see pin 4,5 & 9. These are filament pin which used to boil the electron at the cathode. It can be connected for either 6.3v in parallel (Pin 4&5 with 9) or 12.6v by serial (pin 4 with 5) ac or dc, sound funny...lol

El34 is a power pentode tube. Unlike triode, it have 3 grid(g1, g2 & g3), a anode(a) and a cathode(k). Pin 2 and 7 will be the filament. This tube only have 8 pins, mean that it use 8 pin noval socket.