• 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.

It's a triode

If you search for that tube number, you'll find a store that sells them for 4$USD... They have about 10 left so I didn't post the link to make it harder for tube harvesters to hoard them.

I considered buying a couple because it would be a cool level meter but since I have no experience with a DHT, it seems like a PITA.

If someone has a design I could use to feed it audio and get it to flash like in the video (on the page of the store you can Google), I'd be down. I wonder if you could run left and right heaters in series from the same supply like modern tubes? 0.8V for a heater is kind of complicated (save for making a 1.25V supply with LM317 and using a diode).
 
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