Applies to: EUTs with analogue or digital inputs and analogue or digital outputs.
Aim: To measure power-line (mains) related products in the output noise of the EUT.
Method
If the EUT has a digital input, it is fed with a digital-zero signal; if the EUT has an analogue input it is
terminated with 50R (or 25R if unbalanced). The operator nominates either 50Hz or 60Hz power-line
frequency.
The RMS summation of the signal components in the EUT output at the power-line (mains) frequency
and its second through fifth harmonic is reported for both channels, in dBFS (in the case of an
analogue measurement, this is equivalent to dB below the specified D/A line-up).
Note: only components at the power-line (mains) frequency and its second through
fifth harmonics are included in this test. Artifacts from a high-frequency switching
power supply are classified as spurious components.
References
http://resources.prismsound.com/tm/dS3_Applications_Manual_A4nc.pdf
AES17 - SNR(Mains-50Hz).png