for those interested in my experience with vintage amplifiers, here are some thoughts.
To me, the main limitation my two amps (Yamaha M85 and Denon POA 1500) is the binding posts. They are not 5 way and do not support banana plugs, and wire gauge is limited. With such powerful amps, it seems to me they would benefit from new binding posts that allow use of better speaker cables. I plan on replacing both with suitable 5 ways, both are a bit of a PITA as the original bindings are soldered directly to a PCB, I'll need to jimmy-jam something to get them to work, but I think it will be worth it.
The Yamaha, at 325 wpc/4 ohms, sounds great thru my 3.5's, the Denon sounds good but I can tell a difference in the two amps. The Yammy has LED power meters (bar graph type), the Denon has sexy analog meters and wood side panels, definitely a better looking amplifier. I have both a black face and a silver face for the Denon. I'm using the Denon while I update the Yamaha binding posts, then we will see.
As with any vintage equipment, I'm looking at a restoration at some point, but that's what is nice about having a backup.
I'm using a Bluesound Vault for my digital files, using the built-in DAC of the Bluesound. Its pretty good and don't know if a separate DAC would be worth the investment. Also running a Kenwood KD-5100 turntable that I found a couple of months ago, new in the box, a time capsule from 1981. The Denon preamp has inputs for both MC and MM carts, but you have to physically move the tt rca cables to a different pair of jacks when you go from MM to MC. I want to eventually get another preamp that has a bit more flexibility in cartridge load, or an external phono stage. So that's where I'm at, stick around and who knows what I'll have next month!