Equivalent Input Noise (MM)
Equivalent input noise (EIN) expresses a phono stage’s noise as an equivalent voltage at its moving-magnet (MM) input, before amplification.
It may be quoted in microvolts (µV), nanovolts (nV), dBu or dBV. Lower voltage means less noise; with the same decibel reference, more negative means less. dBu and dBV use different references. Output noise is measured after amplification.
Equivalent Input Noise (MM) — Phono Preamp
Confirm that the figure belongs to MM mode. Compare the gain setting, source impedance connected during testing, bandwidth (measured frequency range) and weighting (frequency emphasis). Missing conditions prevent a fair ranking.
A shorted-input test cannot predict every cartridge’s noise: the cartridge’s impedance affects the result. Low EIN also cannot guarantee a hum-free system; interference can enter elsewhere. Signal-to-noise ratio compares signal with noise, rather than stating noise voltage. Noise density in nV/√Hz is not total noise over the measured frequency range.
Sources
- RaneNote 145: Audio Specifications — Rane
- iFi ZEN Air Phono: Technical Lowdown — iFi audio
- Analog Devices: USB-Powered Hi-Fi Phono Preamp — Analog Devices
Sources
- Analog Devices: Op-amp Noise — Analog Devices
- Analog Devices: Voltage and Decibel Conversions — Analog Devices