Yup , don't think I can do what u suggested . When I switched to internal electronic , the imbalanced in the right & left channel is obviously .
Now I play by adjusting the trim pot provided in Tube Repro with much more gain in the right channel , easily 4-5db I thk . Thanks
You have a major channel imbalance with both internal and external electronics which points to the head or the head switch as the source of the defect. Misadjusting the Tube Repro L/R gain to balance out the channels is not the proper fix as you may or may not know. Cleaning the head switch with Deoxit D5 may be worth a try and should be easy. Also examine the head surface with a strong magnifier.