A wearable system for monitoring at least one physiological event or physiological characteristic of a wearer comprising: (a) a wearable comprising: (i) at least one substantially non-electrically conductive yarn; and (ii) three conductive electrodes, wherein a first electrode and a second electrode are placed on the front portion of the wearable, and wherein a third electrode is placed on the back of the wearable; and further comprising (b) at least one means (10, 20, 30) for conducting from the wearable, electrical signals associated with the at least one physiological event or physiological characteristic of the wearer, wherein the means (10, 20, 30) for conducting electrical signals is electrically linked to at least one means for signal pre-processing; and characterized in that the means for signal pre-processing comprises a circuit comprising: (i) a tuned low-gain high input impedance first stage of amplification of electrical signals fed to the circuit from at least two conductive electrodes (5, 15); (ii) a high- pass filtering stage (160, 180); (iii) a high-gain second stage of amplification of output from the high-pass filtering stage (160, 180); and (iv) a feedback stage wherein the common-mode electrical noise from the first stage is buffered, amplified and inverted before being fed back to a lead to the third conductive electrode thereby increasing the common-mode rejection ratio (CMRR) of the system. (a) a wearable comprising: (i) at least one substantially non-electrically conductive yarn; and (ii) three conductive electrodes, wherein a first electrode and a second electrode are placed on the front portion of the wearable, and wherein a third electrode is placed on the back of the wearable; and further comprising (b) at least one means (10, 20, 30) for conducting from the wearable, electrical signals associated with the at least one physiological event or physiological characteristic of the wearer, wherein the means (10, 20, 30) for conducting electrical signals is electrically linked to at least one means for signal pre-processing; and (i) at least one substantially non-electrically conductive yarn; and (ii) three conductive electrodes, wherein a first electrode and a second electrode are placed on the front portion of the wearable, and wherein a third electrode is placed on the back of the wearable; and further comprising (b) at least one means (10, 20, 30) for conducting from the wearable, electrical signals associated with the at least one physiological event or physiological characteristic of the wearer, wherein the means (10, 20, 30) for conducting electrical signals is electrically linked to at least one means for signal pre-processing; and (i) a tuned low-gain high input impedance first stage of amplification of electrical signals fed to the circuit from at least two conductive electrodes (5, 15); (ii) a high- pass filtering stage (160, 180); (iii) a high-gain second stage of amplification of output from the high-pass filtering stage (160, 180); and (iv) a feedback stage wherein the common-mode electrical noise from the first stage is buffered, amplified and inverted before being fed back to a lead to the third conductive electrode thereby increasing the common-mode rejection ratio (CMRR) of the system.