I have finally replaced the stock coupling capacitors with 33uF Panasonic FCs and the power filter cap with a 1500uF Rubycon MBZ. The sound improvement is huge (power filter cap made only a little difference anyway)
RMAA results for the capacitors mod:
All the testings were done on lineout 2 because lineout 1 is still ko. I thought the problem was caused by a bad coupling cap, but it is not the case. I will replace the opamp as I get some 4562 to see if it fixes the problem.
Any hint about fixing my front channel will be appreciated!
RMAA results for lineout1
