We rate Sensitivity, Distortion and Signal To Noise ratios, etc., relative to Rated Output levels.  Many competitors give you exaggerated  values of  Distortion by measuring distortion at levels that provide best sounding results.  They also come up with greatly exaggerated Signal To Noise ratios by measuring noise relative to maximum output or even at clipping level of the output.  We rate these specifications at the levels for which the product is meant to be used.  So, an Esoteric Sound Specification of S/N of 80 dB relative to 300 mV output may compare to a competitor's specification of 92  dB relative to "clipping."  The problem is that you don't operate a preamp at clipping.  You could not bare listen to it and the occasional distortion peaks.

This also applies to our turntables.  When you see rumble figures better than 60 dB, you should start trying to find an LP with a dynamic range figure better than 50 dB.  The odds are you won't.  The fact of the matter is that measuring turntable rumble and signal to noise ratio is quite difficult and not standardized.  We try to use the figures that best represent real world conditions.  I practical terms, you will never hear any audible contribution from any of our turntables caused by the turntable itself.  You will probably hear noises from the records themselves or hum picked up by your phono pickup that dwarfs that of the mechanics our our turntables.  Rumble figures approaching 70 dB are very good and can be achieved, but figures in excess of 80 dB are approaching fantasy.