SNR (MM)
SNR (MM) is the signal-to-noise ratio of a phono stage’s moving-magnet input. It compares a stated reference signal level with background noise, in decibels (dB).
A higher figure means less noise relative to the signal when measurement conditions match. A noise voltage, or equivalent input noise (EIN), describes a noise level rather than this ratio.
SNR (MM) — Phono Preamp
Use the MM phono figure, not the moving-coil (MC) result or an amplifier’s line-input SNR. Each describes a different input path or setting.
Compare the reference signal level, gain, bandwidth (the measured frequency range), weighting (how different frequencies count toward the noise result) and source termination (the impedance connected during testing). A result referenced to a cartridge-level input signal is not automatically comparable with one referenced to maximum output.
A-weighted and unweighted figures are not interchangeable. If conditions differ or are missing, the bigger number does not establish the quieter stage.
Sources
- Rega Fono Mini A2D Mk2 manual — Rega
- Pro-Ject Phono Box technical specifications — Pro-Ject Audio Systems