ZXY DU19 Permalloy Signal Isolation Transformer The ZXY DU19 is a high-fidelity permalloy signal isolation transformer designed for professional analog audio equipment. Featuring a high-permeability permalloy core and oxygen-free pure copper winding with 1:1+1+1 multi-winding structure, it delivers ultra-wide flat frequency response, low signal distortion, and excellent electrical isolation. This transformer effectively eliminates ground-loop hum, common-mode noise, and