Yamaha vs Marantz vs Denon

I have a Yamaha RVX 1500 which is a few years old, for a receiver it does a decent job of stereo but that said it cannot replace separates for sound quality. I prefer to keep two systems for that reason. TG

I've sold all those brands for about a decade and a half, and I have to completely disagree with Doggg. The Denon is anything but analytical, while at different price points, Marantz's sound has been somewhat of a mixed bag. If anything, the Yamaha's have been somewhat more analytical, by themselves. Older Marantz was thinner sounding at the lower/mid price points, but smoother near the top of their line.
The Yamaha's sound at anything bellow the Reference pieces have traditionally been a bit cool sounding, slightly recessed in the mid-range, a bit thinner in the bass, extended on top sounding. They did much much better usually being driven with better amplification (so did every other receiver, but the Yamie's really sounded better with outboard amps). The Flagships were better balanced.
However, I would want to know more about your system (speakers?), how you set it up, associated gear, room, acoustics, etc, before I recommend anything - because it depends.
However, without knowing your variables, the Denon will have a more warm full-bodied bottom end, good mid-range, overall musicality, and descent enough detail and top to be the most musically satisfying, as a stand-alone receiver, IMO. Basically, I think it will most approximate the NAD at that mid-level price point you're looking at, yes. I also think the Denon's will have bette dynamics than the Marantz from my experiences. I owned a couple Marantz pieces myself, a Denon or two, and some Yamies over the past 2 decades. Again, also sold/installed them professionally also.
Hope this helps

Thanks for the advice so far. I currently have a pair of B&W DM602's and a Wharfedale sub. I am yet to add any speakers, but would probably look for smaller B&W's for the rears (still 600 series) and a B&W center.

I can't justify the cost or cabinet space to keep a separate stereo setup, hence my desire for the receiver to deal well with music as well as movies.

Marantz & denon are owned by the same company. From everything that I've read as well as experienced denon has been better at video and surround processing and the marantz line is talked about as being more musical. Imho this is how they sounded to me when I listened to them. I was comparing the current top of the line marantz and the comparable ($1500) denon.

I'd be looking at the Harmon Kardon AVR-354 and/or the best Denon you can afford for your speakers. The HK's have always delivered excellent current for a receiver, and are the most refined at that price point.
Still, I'd be using some receiver like this, and then slidding some slim-built 2 channel amp on top for added "umph" for the L/R...freeing up more current to drive the center and rears. But hey, that's just me...I like good sound and know what a separates amp can do that a receivers amplification can't.
Just know that the receiver will give you 60% of the capable performance, and a better amp will give you another 30%+ performance boost. And that's no stretch
Good luck