In a nutshell: Voltage noise referred to input (measurement bandwidth = audio A-weighted) = < 300 pV SQRT/Hz (JFET = NXP BF862) Bandwidth = ~ 0.1 Hz - ~ 1.5 MHz Input impedance = 1.1 M ohm Voltage gain (dB fixed) = 60 dB (output = single ended) = 66 dB (output = balanced)