Amazon.com: EI57 25 Power Transformer 15W Input 380V220V ferrite core to AC 6V 9V 12V 15V 18V 24V 220V Single and Dual Audio Transformer (Color : 220V Single, Output Voltage : 9V) :
10pcs/Pack 600 : 600 Ohm 1:1 EI14 Isolation Transformer, Audio Transformers Used in Radio Communication, Broadcast Television, Automatic Control