You have a really good set up there.
The VII pre you have is the best of all the iterations with better regulation on the boards ( see the feed form the back-plane to additional regulation prior to the phono stage)
The VIIIs is a lovely power amp.
The weak point is the single six PSU, this is the limiting factor and although not many come up for sale often look for another VI to have separate psu for each channel or a XII psu (or two) or a IX psu will bring major improvements.
The VII pre you have is the best of all the iterations with better regulation on the boards ( see the feed form the back-plane to additional regulation prior to the phono stage)
The VIIIs is a lovely power amp.
The weak point is the single six PSU, this is the limiting factor and although not many come up for sale often look for another VI to have separate psu for each channel or a XII psu (or two) or a IX psu will bring major improvements.