Yamaha house sound is slightly laid back that's true. But then you said you weren't keen on the Denon because you heard one that sounded a bit coarse.
I think your speakers will compensate for that anyway, they are not at all laid back so you should get a good balance there. Of course the character of your cartridge and phono stage will also factor in too...sometimes you just have to take a punt. I really don't think it would be a problem.
I know it's hard to describe in a few words. I need plenty of attack. Ther course thing.... my cyrus is on the lean side but its smooth not course. If you ever did any photography it's like a higher speed film for low light where its grainy. I know , it sounds bollocks but I know what I mean hah.
OK...I'll buck the trend and say that unless you only want to spend a few hundred, I wouldn't pay strong money from anything too vintage (unless "top end vintage") as unless already serviced, just about all will either need or benefit from one. Transistor output stages in the '70's for example, simply weren't up to the reliability or longevity of modern counterparts and anything approaching 40 to 50 years old will almost certainly have drifted miles off value and things like electrolytic caps would need looking at. You can be lucky and find a one careful owner, low miles example, or one that's never been run too long or too hot but at that age, I'd put half the budget towards a service. New you get better bang for your buck imho as it's pretty hard to find a really bad or really unreliable class A/B amp these days.
The best value I think is in the 5 to 10 yr old category. Loads to choose from at a grand or less.