APOS lists this already for $599 in US. Not bad based on the improvements they've made. I like the socketed amps, though 47920 is probably as good as anything else you'd likely try. Some people think OPA1612 is a little warmer/rounder so anyone that likes that, or thinks they hear a difference, may like those better,
DX7s used two 9038q2m stereo DACs in balanced fashion, running two channels in parallel per side. Now they use a single 9038 Pro which is 8 channels, so they must be running 4 per side. Balanced output will make this an option for some pro audio use as well, but the 4V RMS is a little low on the balanced outs (about 14 dBu vs 18-24dBu in most Pro DACs).
Excited to see how you all measure this one, because the competition is heating up in this arena, and a converter of this caliber, at this price, seems like a treat compared to just a couple of years ago.
I am not one to necessarily choose ESS over AKM, and have not heard the D70 (maybe it's close to this?) but the DX7s is a stellar converter for the few hundred bucks they are fetching now, and this looks like a natural progression.
Particularly, I can see this subbing for the DAC3, ADI2 and HILO for studio DAC use. At $599 those others would have to be a significant step above this, and based on Topping's track record I can't see that they will be.