DIGITAL POPS WITH HDMI CABLE IN DDC TO DACS CONNECTION

Simonb This problem didn’t occur with USB because, being asynchronous and buffered, both DACs eliminated it. So today I’ll look for a cheap but as short a cable as possible to experiment...

lanz0003 I hope this gets resolved because I won’t change the DACs, and I refuse to upsample and leave all the files at 176 or 192 kHz to avoid pops from frequency changes, because I don’t like how upsampling sounds on the Lumin. And honestly, the improvement with the DDC U26 was two or three levels higher (and it only has about 100 hours of use).

If there’s no solution, the improvement is worth accepting.

The pops are due to your DAC handling bit rate changes. 
Are you using Lumin native software to stream? I don’t remember if it has a setting for a resync delay (don’t think it does). But I know Roon has it and it will in some cases completely eliminate the pop. 
Cables will not affect this. It’s your DAC. 

Before concluding the dac is the fault, try bypassing ddC to see if the pops continues. The pop / static noise I was experiencing is not due to sample rate changing. When I connect streamer to dac directly the issue is gone. Also, when I used much cheaper ddC (smsl po100 pro) there is no issue with either DAC. I return u18 since. I maybe talk about completely different issue even the symptom is similar. 
 

btw I have not heard any reviewer reporting popping issue with SU-X due to sample rate changing. The issue was with lower end smsl dac. 

audphile1 I’ve always used Lumin’s native software because it sounds better than Roon, and I’d rather put up with the pops than lose sound quality. Unfortunately, Lumin doesn’t have that resync delay feature.
Today I unplugged the 20-inch HDMI cable from my Roku: the pops are still there, and the sound was terrible.I went back to the Chinese HDMI cable.

Some dacs are more sensitive. But if the pop is not too bad just ignore it.