That new ak chip isn't as near important as the amp and output circuit and how fiio will tune the m15, the clock systems are already very good. I imagine the pro and 15 will be a hair cleaner in their output. But the cheapest dac from ak, or ess can be made to sound as good as their top of the line stuff with good clocking and the right output.
Take this 'low line' ess in the m6, observe the specs. Dnr up 121 decibels- useless you would be deaf very quickly to realize this number- and no that doesnt make it any cleaner at normal listening levels.
Ok THD + N -115 db another amazing number. That counts imd too. So inaudible. These specs are already to high to be realized. So the new dac with 130 db SNr and 119 thd+n is just marketing. The amp section and output and LPF tuning are what matters.
I have an ap80 with an 'even cheaper' older ess dac than the m6, and it sounds supreme for such a tiny dap. Tuned very clean and neutral with lots of power.
Just saying lol. I don't get excited by new dacs, it's the amp/output stage that gives you the sound characteristics really.
U8 uses a variation of the 038 ess chips, but it sounds like an old Wolfson or BB with a beautiful natural warm sound of of a supposed neutral exacting dac. Shanling m3s and m2x sound exacting and very neutral even a touch cold- but they're both using AK velvet sound dacs which people perceive to be warmer.
Omg! How did that happen?
The amp and output stage and the LPF, they engineered it to sound that way.
Ok I'm done lol