• 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.

Can a cheap autotransformer serve as parafeed OPT?

I found this thought interesting... Cheap autotransformers are available with various combinations of taps for $15 to $40. Is there a possibility of one of those serving in a circuit like this? With autotransformers you can basically use any of the taps as primary or secondary to get the impedance you're after. Of all the industrial autoformers available there is a pretty wide range of voltages, what are the chances of hitting on the right impedance match for a parafeed with any tube? not just the one shown here.

Espressivo Headphone Amplifier