The NL125/6 Band Pass Filter module employs two active sections to control the variable high-pass and low-pass characteristics along with a mains frequency Notch filter (jumper selectable for 50Hz or 60Hz). It is a combination/replacement for both the NL125 and NL126. The NL125/6 is commonly used in combination with our NL100AK/NL104A AC Preamplifier headstage and module for band-pass filtering of signals from extracellular recordings.
The low frequency cut-off point can be set continuously from 0.5Hz to 5kHz with a single turn potentiometer, in four switched ranges. Similarly the high frequency cut-off can be set continuously from 5Hz to 50kHz in four switched ranges. DC and WB (wide band) switch positions by-pass the lower and upper filter sections, respectively.
The unit has two active notch filters which provided for the rejection of line frequency interference; this is selectable on the board, by the user, as either 50Hz (as the original NL125) or 60Hz (as the original NL126), with a 20Hz notch width (-3dB points).