Tubes Asylum

Posted by Tre' (P) on March 24, 2014 at 16:12:07

In Reply to: RE: How important it is to have the voltage of the filament being elevated ? posted by akltam on March 24, 2014 at 07:44:24

"Just wondering how important it is to have the voltage for the heater being elevated ?"

It depends on the circuit. Sometimes you have to float the heaters to keep from exceeding the cathode to heater voltage rating of the tube, sometimes you float the heater to keep the heater noise out of the audio.


"Any simple method to provide an elevated voltage for the heater supply ?"

Just make a voltage divider, two resistors in series from the B+ to ground.

The value of the resistors will determine how much current the divider will draw and the voltage at the intersection.

Connect the "ground" point of your heater supply at the intersection of the two resistors instead of ground. Placing a cap to ground at that point is probably a good thing. 20uf should work fine.

Tre'
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