The Meridian DAC Uploader running on on Mac OS 10.10.5 consented to recognize and upgrade my Prime (and this while passing through the Prime Power, since I only had a tiny short mini-USB-ended cable on hand; why, Meridian, why?)

It did take several tries - each implying that it was loading the update, but then ending up with the Prime in a state which the uploader still thought needed upgrading - but eventually (the third cycle, I think) I reportedly have v1718 on the Prime.

Playing some MQA titles from 2L, the fourth LED lights and it does indeed sound quite nice; any deeper judgement than that is a work in progress.

Photographer, computer geek, listener, lad-about-town.
{ Lumin U2 Mini, ( {Apple TV, other HDMI gizmos} -> HD621) } -> 861v8 -> BAT VK-6200 -> {2x804S, HTM3S, 2xDS8S} -> ears.