• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Current sourced heaters

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diyAudio Chief Moderator
Joined 2002
Paid Member
Hello all,

I have seen through searching that some of you have actually tried out current sourcing the heaters of driver tubes. Taken we find a cool enough place in the chassis to protect the taxed heatsinked IC from longtime failure, do you recommend this method sonicwise? what possible benefits did you experience vs grounded pot AC or RC filtered DC?

Regards
 

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Current sourced has an inbuilt slow turn first of all due to the resistor after the ccs. It helps to protect the tubes.

BEcause the current is controled, the tubes gets heated up properly, the sound of a DHT will be more consistent than using AC as mains is always changing.

Sonically ccs DC is as close to AC than normal DC without the hum.
 
diyAudio Senior Member
Joined 2002
Hi,

When you make a plot of the DHT tube it will show almost the exact same curves when the heater is fed from a current source as it would fed from AC heaters.

Without the noise, hum!!.

Most of the time I prefer DC heating, that's more to my liking, YMMV.

Cheers, ;)
 
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