Abstract: Systems, apparatus, and methods are disclosed for conveying signals between a patient and monitoring and treatment devices. An EP system provides large-signal input protection and RF ablation signal noise suppression while preserving the integrity of relevant components of small signals. The EP system has a low-noise amplifier topology with minimal hardware filtering. An input protection circuit shunts to ground signals with amplitude above an ablation voltage. An RF filter circuit linearly attenuates the signals between 300 kHz and 600 kHz. A low-frequency feedback circuit drives a common mode node of the RF filter circuit for additional attenuation. A signal amplification circuit amplifies the signals between 0.01 Hz and 1000 Hz. A fast recovery circuit feeds back a low-frequency voltage signal to the signal amplification circuit to gradually reduce offset voltage of the signals. A high-resolution A/D converter converts the signals from the signal amplification circuit to clean digital signals.