yeh hai kia ??? yah black box ,
when i had a chinese pre , it was given same box
in which i found ,resistor , toroid and and fuse
bahi yeh buz buz ki sound common hai , simple prob yeh hai kay , rumhari rca wire is closer to current wire , make sure that RCA wire is far away from these live wires , from head unit to Amplifer , u must check from head unit , cause , connector and rca are very close over their
phir bhi a rahi hai , GET good RCA pair , having thick insulation to prevent electromagnetic wave interfereing with sound wave deliver by HU to amplifer