Need super quiet 6.3V filament supply schematic

[phrarod]

Anyone have a schematic for super quiet 6.3v filament supply? Much appreciated. 1A per tube should be plenty.

 

[Zen Mod]

make CCS ;

or even better - heater between gyrator and CCS

in case that's indirectly heated tube , don't forget to elevate heater at least 35V above cathode potential

 

[phrarod]

I've been hearing a lot about CCS lately. Do you have a schematic or reference URL?

Gyrator?

 

[Zen Mod]

http://www.diyaudio.com/forums/tubes-valves/38248-new-dht-heater-4.html#post2024952


up and down

 

[astouffer]

The easiest CCS is built with an LM317 regulator. Page 18 of the datasheet has an example. http://www.national.com/ds/LM/LM117.pdf

The L200 chip is good for more current but slightly more complex. http://www.st.com/stonline/books/pdf/docs/1318.pdf

 

[Matt BH]

make CCS ;

or even better - heater between gyrator and CCS

in case that's indirectly heated tube , don't forget to elevate heater at least 35V above cathode potential

These are good points. Why do you need a low noise heater supply? are you getting noise troubles because of the inherent diode between heater/cathode? (assuming indirectly heated)

If you really need low noise then the constant current designs in the datasheets Astouffer posted are the way to go. Nice and gentle on the heaters too.