Abstract: Two magnetoresistive (MR) elements are connected with two matched impedance elements in a bridge arrangement for sensing magnetic flux manifesting information recorded on magnetic media. An alternating current (AC) bias is applied to the bridge's input, and short-term variations in the bridge output signal envelope are detected as representing recorded information. Long-term (average) variations in the signal envelope are also detected and used to adjust the AC bias to maintain a constant average envelope. Additional bridge inputs may be connected in parallel with the first, and the additional bridges' outputs used to derive additional information signals without any additional AC bias adjustment circuits.