That’s true for these Vu meters repurposed as gauges for a Raspberry Pi server, and we think the build log is as informative as the finished product is good-looking. As [MrWunderbar] admits ...

[Daniel] sent in his Nixie tube VU meter. It uses 14 Russian IN-13 Nixie bar-graph tubes. He built a custom circuit to amplify, filter, smooth and feed a voltage divider to assign signal levels to ...

It is roughly the average signal level though not precisely. A VU meter is not recommended as the sole metering method for digital systems - it is too slow to catch transients which may overload the ...