I changed all the old electrolytic caps in the channel cards of both amps and also all the electrolytic caps in the relay section itself (there are 4 caps in the relay section). This made zero difference to the problem. However I have not changed the old big PSU caps yet, - there are 4 large PSU caps in each amp, - each one a blue Aerovox 17000uF caps. I was thinking its possible the problem is being caused by these old PSU caps taking too much time to give power to the relay section, - is this possible?
Any help will be apprecited.
I didn't find the right solution from the Internet.