Yes there is 2x PCM1702 20-bit R2R Dac in this your DAP. Great DAP! Hifiman had also black version with PCM1704 which is 2001 Texas Instruments 24-bit DAC (Obsolete now).
I tried to pickup a Black R2R2K, however even as an expat in P.R. China the pricing for the few available is not good. With the Hifiman R2R2K you give up a tremendous amount of features and usability that's taken for granted on any modern player, equally if you listen to an R2R2K there will be no turning back...
Only other portable R2R solution is from Luxury & Precision passing $3K, which TBH is questionable for yet again a device with a limited feature set. The Red Hifiman R2R2K remains to be available and at reasonable pricing for those wiling to dig a little.
I find Rock & Metal is good on WM1A, just need to fine tune the CFW, region and headgear. There's just something off with some of the CFW as the male vocals tend to smear, coming across a being artificially stretched, however this seems more confined to 70's rock where the vocalist is very much designed to be upfront and centre with the music surrounding.
I believe it's an artefact of looking to present a more 3D, holographic experience, however this can and does break certain genres. Inversely Sony is deliberately overly conservative with WM1A as it wants to project the WM1Z as the better DAP. The 1Z is, yet the sum of it's parts don't add up as the reality is that the vast majority of the 1Z sound signature is in software not hardware, not that owning a WM1Z is not a bad experience by any means
Q-6