The NL820A Isolation Amplifier is the module at the heart of the isolated amplifier range of components, ideal for AC coupled recording applications such as EEG, EMG and ECG in the research environment (the NL820A is not MDD certified). The NL820A Isolation Amplifier is a four channel unit with independent gain and filtering control of each channel as well as a mute facility. The NL820A MUST be used with a preamplifier from the discontinued NL822/4 & NL832/4 ranges or our new NL844.