I found this site...

[zeitghost]

http://www.audioasylum.com/forums/tubediy/bbs.html

It's populated by people even sadder than we are...

They've got the asylum bit right...

[DaveB]

And yet you still managed to find it ZG

[Euro-commuter]

http://www.audioasylum.com/forums/tubediy/bbs.html

It's populated by people even sadder than we are...

They've got the asylum bit right...

I'm so sad I went and looked. Found someone asking what could cause hum on a valve.

Heater-cathode leakage, any fool knows that.

[threaded]

Why not correct them i.e. light blue touch paper, and retire...

[Euro-commuter]

What gets me is the earnest discussions about the musicallity of various types of valve... seems to depend on the position and type of getter.

And the pros & cons of Ultralinear versus Triode and Pentode connection...

Most of which seems to miss the fact that the output valves they are talking about aren't pentodes at all but are beam tetrodes.

But why spoil the fun with facts, eh?

Well, sure, but you can't expect kids to know the difference.

Anyway they're basically the same thing: the suppressor grid is normally connected to cathode, as the beam plates are internally. They both fix the secondary anode emission caused by the positive charge on the screen grid; and they both introduce the same non-linearity that forces you to say goodbye to single-ended Class A (the real valve sound).