Looking for help understanding clock usage in my system

Hi sls883, the FS refers to the clock frequency coordinated via I2S between the DDC and DAC, which is the master clock. In my case, since I have two DACs, when I use the SMSL SU-X I use 512FS, and when I use Holo Cyan 2 I use 22/44 MHz. This determines the stability and synchronization of the system. I don't have the R30, but I think you should use 22/44 MHz. How can you find out exactly which clock your DAC uses? Connect your DAC to the PC, and XMOS will show you the clock frequency it uses in one of its tabs; that's the one you should select in the U26.

Regarding the DSD Flag, it's only used to designate which PIN the DSD assignment is located on, which varies depending on the DAC manufacturer. However, in your case, that doesn't apply, since you only need to connect the I2S to the IIS-G and the assignment will be automatic because it's between Gustard devices.

I hope that's clearer.

Regards!

@tutonunez Thank you for the reply!  I shot an email to Gustard to see what they suggest for the clock frequency.  They've been good about responding to emails.  If I get a chance, I'll try connecting to a pc.  

I don't know if it's correct, but I found the following information with Google:

For the Gustard U26 to work correctly with the Gustard X30 DAC over IIS (I2S), you should select the 128FS MCLK rate. While the U26 allows you to cycle through multiple rates, 128FS is the standard "native" master clock frequency for Gustard’s current flagship ecosystem (including the X30 and R30) to ensure proper synchronization and avoid playback errors.

Well, Gustard has replied already.  They suggested 22/24 Mhz.  I was mistaken when I listed 22/44 Mhz. 

So much for Google... 

Pretty impressive that Gustard replied within an hour and it was like 11:30 pm out there. 

Congratulate, Op.  Simplicity is beauty. I also use the Zen 3 in my second rig, and its sound is romantic—yes, that’s the right word for it.