DDC Comparisons

@soix The Denfrips is over $100 cheaper, but the ease of Amazon returns might make it a good possibility....

Something to consider is the pin out on the I2s connection. Your Gustard dac should have a pin out that matches the U18.

I’m using the shortest version of the cable linked below. It’s designed specifically for I2S. You want to use a short cable.

You could probably find a pin configuration that works with a Denefrips, but I'd look into it if are planning to go that route. 

https://wyred4sound.com/products/hdmi-pcocc-premium

@sls883 thanks for the tip - 

If planning to use I2S for the long run make sure both dac and ddc have pin configuration ability. With this you can use ddc with any dac and vice versa.

As for ddc, I have Denafrips Gaia, wanted highest quality clock, power supply to that clock and usb optimization on input. I tried intermediate steps with I2S in the past, compared to my already optimized usb I2S was not an upgrade, adding the Gaia tuned the tables. However, not everyone is going to hear the full potential of Gaia with present streaming setups, Gaia for mature/fully optimized streaming setups.

Singxer SU6 is a nice mid price ddc, may find used or stretch the budget a bit.

Oh crap, please disregard my prior recommendation on the U18.  I meant all else being equal I’d take the SU6 over the Iris. 🙄😖  I’m not familiar with the U18 but highly doubt I’d take it over an Iris.  Sorry for my confusion.