Dont mind if I post my problem here. The left side of my CKKIII is working fine. Its the right side thats giving me headache. Irregardless of how much i turn the trimpot(R43), the reading across R47 still read 0mv, even if full clockwise. The output transistors are cold, at room temperature. OPA2134PA is used. Pin 7 reads about 50mv which is stable. Its Pin1 thats irregular. It fluctuates between 50mv to 1.16V. All solder joints had been reflowed at least 3 times and all resistors are checked. I thought the transistors are cranky and thus replaced all transistors on board, BC550, BC560, output and 2SK74, 2SK174. Opamp had been replaced too. The problem still exists. DC offset with OR fluctuates between -20mv to +70mv. It will rise to 'peak' then fall. Checking with operation voltages supplied by amb shows that voltages before the OPA is fine. after OPA output 1+v, all following voltages are not in line. Does anyone have suggestion where do i carry on troubleshooting?