Moonriver Audio produces two versions of optional DAC, both using the ESS Sabre 9010 DAC.  Because the integrated only has one digital input, listeners need to choose one or the other:

• the USB DAC that supports PCM up to 24/384, MQA, and DSD up to 512
• the S/PDIF DAC that supports PCM up to 24/192

What was desired for our USB DAC module was not to make an addition rather than an omission; instead we had to be confident of substantially raising the true value and functionality of Model 404 and the 404R, its Reference model.  Jason Serinus first reported on that in his Munich High End Show coverage in 2022 before press release came out in April 2024.