THAT 218x (2180/2181 depending on trimmable/pre-trimmed version)
If the VCAs were at unity, it might not be the VCAs... or it might be the summing amp... Can you switch the VCAs out and does it get quieter?
That said, I konw that Scenaria had a console a while ago that you could switch the VCAs out on. They were 2150's or 2151's. The board sounded much better with them out.
Try 218x THAT VCAs and see if that lights your fire. Search the GSSL comp mets for more info. there's a million posts on the subject.
Keith