hifi engine

TEAC A-500i Problem

Hi, this is my first request and I wonder if anyone out there could help me?

I have a TEAC A-500i Integrated Stereo Amplifier with a slight problem. When cold i.e. mains has been off for some time and play from any source, it takes around 2 minutes to gradually with some crackle and distortion to start operating correctly.

At first I thought it to be the 4 capacitors on the PSU (C801-804) have replaced with some slightly larger 6800uf @ 63V audio grade Samwha Gold. The original capacitors 5300uf @ 50V.
Another thing that I have also noticed is the balance control seems a little offset to the left hand speaker...
Have checked the BIAS (CN59 & CN60) current adjustment to 11mV with two calibrated FLUKE meters, when fully warmed up.

Any thoughts on this matter would be gratefully received.