Noise is very special signal. The RMS of noise is the same as the standard deviation of that random signal. It is known that in noise there are peaks larger than the standard deviation i.e. RMS. Thus the meter reading is higher, supporting my impression that it is more a peak meter (see sine) than an RMS meter.
- With -14dBFS RMS / -11dBFS peak 1kHz sine the VU meter shows about -11dB
- With -14dBFS RMS / -8.5dBFS peak pink noise the VU meter shows about -6dB