Volume unit (VU) meters are cool — it’s an undeniable fact. For some reason, humans just dig lights that flash along with sounds. You can build a VU meter using LEDs, or bulbs if you’re trapped in 1972. Or, you could use special vacuum tubes. [mircemk] did just that in their latest VU meter project.
This is a companion discussion topic for the original entry at https://hackaday.com/2024/03/22/build-yourself-a-vacuum-tube-vu-meter/