I bought an Esoteric K-01X a year ago and since then I have rediscovered all my Red Book CD’s.I’m not sure but I think that’s maybe because like it’s predecessor the earlier X-01, it uses 8 x PCM1704 R2R mulitbit dacs for Redbook conversion.
And the X in the K-01X may designate that it also has a Delta Sigma (bitstream) dac to do SACD with.
ESOTERIC X-01: A killer Redbook player
8 x PCM1704 – SM5847AF – SM5819AF: VRDS-NEO Transport.
X-01
http://www.hifi-advice.com/blog/wp-content/uploads/2017/01/esoteric-p01_vrds-neo-trans_464pix.jpg
http://www.soundstage.com/equipment/pics/200906_esoteric_x01_800w.jpg
K-01X
http://www.esoteric.jp/products/esoteric/k01x/img/f_photo02.jpg
http://www.my-hiend.com/audiotemp/2015/photo/5.7K01X/K01X0046.jpg
Cheers George