I personally think iBasso should remove the digital out and replace it with something else more useful, maybe another sd slot, or maybe room for even better amp/dac circuitry. Think about it, the DX90 has dual 32 bit 384khz ESS dacs, as soon as you use the digital out you are losing out on some of the ESS quality as the signal is then limited by the digital out chip specs, which is 24bit 192khz, looks like dx90 uses a Cirrus cs8416 chip for the digital out, that chip doesn't have the best jitter specs, so you are taking the low jitter signal from the ESS dacs and passing them through a digital receiver chip which will add jitter, lower dynamic range, increase THD etc. I just don't see how you could actually increase SQ by using the digital out, more like lessen SQ.
Edited by T.R.A.N.C.E. - 5/27/14 at 3:39pm