valve filament voltages

[the cracken]

im making a distortion pedal with a 6H16b-B. the rated voltage to the filament is 6.3V im running it off a 9v battery. how can i drop 2.7v??? how can i work out the values for a potential divider??? or can i use 9v's with a resistor??? thanks for any help!

 

[bychon]

If my Russian is any good, those tubes use 6.3 volts +/- 1.9V and .2 amps.
Ohms law says R = 2.7volts/.2 amps
That's 13.5 ohms optimum if the battery is strong.

In a range of 4.4v to 8.2v that the tube can survive with, you have to kill .8 to 4.6 volts.
.8/.2 = 4 ohms
4.6/.2 = 23 ohms

or you could use a 6 volt battery...

 

[mneary]

You can drop about 2.7 volts with four 1N4004 diodes in series (about 0.6V each). If you are running a 200mA filament from a "9V" alkaline battery it will last about half an hour.

 

[audioguru]

Why use an obsolete high power-wasting vacuum tube? Use a couple of low power transistors or an opamp instead.

 

[crutschow]

If you need to operate off a battery then use four alkaline D cells in series to power the filament. That should give 30 or more hours of operation at 0.2A.

Where are you getting the high voltage for the plate?

 

[MikeMl]

If ya gotta have a Toob, use one of these.