Hi Midiboxers, after fixing my voltage issue, i still have a output problem :( It is very low and there is a lot of background noise: Testtone: test.mp3 I allready checked: 5V @ Ic1 Pin 1,7; Ic2 Pin 1, 3, 6, 9 +12V @ Ic3 Pin 4; Ic6 Pin 4 -12V @ Ic3 Pin 11; Ic6 Pin 11 polarity of c1, c3, c5, c7, c11 ,c16, c18, c20 ,c22, c24, c26, c31, c32, c33, c34 = checked replaced Ic3, Ic6 = no difference FM-Interconnection test = passed Any suggestions what could be the fault? May some other capaciator? Thanks for your help Best regards Marxon