The asymmetry of axial and off-diagonal impedance was investigated in as-quenched and field-annealed amorphous Co67Fe4Cr7Si8 B-14 ribbons. The asymmetry of impedance characteristics can be controlled by DC bias current and torque. When an appropriate uniaxial anisotropy is superimposed very high field sensitivity (about 3000%/Oe) can be obtained. The proposed theoretical model well explains the observed behavior. (c) 2006 Elsevier B.V. All rights reserved.