EL84 Wiring

[GregS]

I'm presently doing a build with an EL84 PP power section. From a schematic I have it appears that the cathodes (pin 3) are connected to another type of grid in the tube (suppressor?). Also, the pin numbers are not in the schematic so I'm not sure what pin that would be. The wiring diagram does not have the cathodes connected to any of the other pins. I'm wondering if this connection is internal and not one that I have to make myself? Pins 1, 6, and 8 are not used in the wiring diagram. From the research I've done all I've come up with is that 1,6, and 8 are internal connections.

Any help here would be greatly appreciated.

Thanks,

Greg

[olddawg]

Originally Posted by GregS

I'm presently doing a build with an EL84 PP power section. From a schematic I have it appears that the cathodes (pin 3) are connected to another type of grid in the tube (suppressor?). Also, the pin numbers are not in the schematic so I'm not sure what pin that would be. The wiring diagram does not have the cathodes connected to any of the other pins. I'm wondering if this connection is internal and not one that I have to make myself? Pins 1, 6, and 8 are not used in the wiring diagram. From the research I've done all I've come up with is that 1,6, and 8 are internal connections.

Any help here would be greatly appreciated.

Thanks,

Greg

Here is an 18 watt Marshall schematic with pinouts. Hope this helps.

[GregS]

Yes it does help as it shows the pin numbers and the internal connections of the tube. From this I can see that this other connection to the cathode is made internally in the tube and not something I have to worry about.

Thanks a lot,

Greg