amp or preamp most important

The best answer is that everything in the chain matters. I have been listening lately to a $16K amp with $4K speakers and those speakers sound so much better then they do with lesser amps that it can hardly be overstated. (Not that the $ means everything, but I am finding now that there are many rather expensive amplifiers that have qualities that no far less expensive amplifiers can match.)

In general "the preamp is more important that the amp" is one of the larger audio fallacies around. I'm not sure where it came from. It's flat-out untrue for me over the course of trying dozens of preamp/amp combos.

Totally agree with TVAD and it is much easier to screw up an amp purchase than a preamp purchase (for the most part). Having said that, both pale in comparison to the importance of the speaker (and room) in determing the overall sound and quality of your system. If you don't that right and to your liking, no preamp or amp is going to make that big a difference, not compared to the speaker and room.

start at the speakers and work backwards, match speakers to room, amp to speakers, pre to amp and finally get a source that will blend with the overall tonal balance you desire, tweek with wire.

IMO YMMV of course...

so amp first!

I agree with the prevailing opinion so far that the amp is more important.

Having said that, I have some experience with the components you mentioned, and if it were me, I would prefer the Anthem Statement D2 over the Anthem AVM50 for sound quality, and I would be willing to offset the additional expense of the D2 by buying a somewhat lesser amp, namely the Anthem Statement A5, rather than the P5 you mentioned. In my experience, the A5 and P5 sound very similar, though obviously the P5 is considerably more powerful. But if the A5 is powerful enough to meet your needs, I would buy it and use the savings to purchase the D2.

Good luck.

1) Speakers

2) Amp(s)

3) Preamp

4) phono preamp

5) Turntable/arm

6) Cartridge

7) DAC