I have the UA2 and am using it with my iphone. I am on the very latest firmware. It is a new purchase. I liked the idea of a 2.5 connection which works for me.
My digital connection is with an OTG capable lightning to USB C cable. I get reliable connections from the iphone to the DAC with that. I also tried a dongle from Ztella that converts USB to lightning and I think that includes an OTG capability. That works with USB C to USB C cables. The issues I am about to describe occur with both connection types.
Two issues:
One, even when I don't move the unit or cable, I get digital noises from time to time. Any thoughts or suggestions?
Two, I can't get the unit to natively play DSD when fed SACD ISO files from the HiBy iphone apps. The UA2 seems to be getting a PCM signal from the phone, and possibly only redbook based on the color. The app is not set to a fixed output resolution (which invokes PCM), and I have experimented using DoP on and off.
I know that the Hiby app can send out DSD; as I have done that on my HiBy R5 Gen II. That involved an Apple CCK, and setting the HiBy app to DoP on.
Any thoughts on these two issues?