Carver AV-705x "Thump" problem

[Rodango]

My AV-705x has developed a bit of a power on "thump" issue. When I turn it on, I here the relays going 'click'.. 'click'' 'click' click ................'cilck'

Its on this last 'click' where the 'thump' occurs.

I am under the impression that the relays should open and close at the same time and if one takes its time in closing, a 'thump' would result.

So what's wrong? Old relays or an external RC circuit which has had some components drift in value?

And does anyone have a schematic or manual you could post?

Thanks!