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I don't get this...

HI,

I'm trying to establish how much current is flowing trough a WE437A tube I use in a phono stage.

My B+ is 184V. On top of the tube ithe primary of an 1:1 interstage with a DCR of 1385 ohm.

I measure 167V on the plat of the tube. This means a voltage drop of 17V over 1385 ohms, so about 12mA,

The tube is biased via filament bias. I measure 2.1V bias on the cathode/positive leg of the heater. So the grid is 2.1V negative to the cathode, so -2.1V bias.

Eying the WE datasheet, 167V on the plate and -2.1V bias should give me 50mA of current (a bit too much I know).

I tried this with two pairs of tubes, with roughly the same results.

The tube swings *very* little voltage at this point btiw.. its sounds great...

Anybody?


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Topic - I don't get this... - Nickel Core 03:18:42 10/16/14 (50)
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