What I get is 2:1 step-down, output impedance 1/4 of tube Ri (squared step-down). What inductance does my tube will see in this case? Any hidden drawbacks in this approach?
Never seen it the other way around. Seen it used as a 1:2 step up.
Sorry don't know the answer to your question. But let us know how it worked out please.
Sorry don't know the answer to your question. But let us know how it worked out please.
my tube is cx112a. I actually did this to have both lower gain (excessive) and output impedance. Not impressed with this choke itself, not in this configuration too, but it actually works. I want more than 2:1 step-down, more like 4:1, and maybe 8:1 tap so I can maybe try use some 250 ohm headphones.
With 112a and this 2:1 choke, the output impedance about 1k5, so practically unsuitable to drive headphones.
The output power with 250R load (1000uF coupling capacitor!!) is 5mW, 4% THD.
Try to use low output impedance tube.
I understand, thats why I want two taps 1:2 with 0.47uf and one more further down tap 4-8:1 with 1000uf . I still looking if I miss something...and headphones is not priority just idea.
I would straight use a proper transformer which can have any turns and impedance ratio as needed.
The 2:1 choke has tons of disadvantages, such as having hundreds of Volts in all of its taps, useless output impedance, etc.
The 2:1 choke has tons of disadvantages, such as having hundreds of Volts in all of its taps, useless output impedance, etc.