i2S clock question


So, I’ve recently added a Denafrips Iris DDC to be able to feed my Musician Pegasus R2R DAC via its i2S input via its HDMI i2S input, and compared to feeding it directly from an SPDIF or USB input the positive results are significant and very apparent.  While I’m aware of the separate internal paths of the i2S connection versus other connections and despite many searches, I can’t find a definitive answer as to how the clocking works in the end.  I know the Iris re-clocks the data and sends it via a separate line within the HDMI connection to my DAC, but I can’t find a clear answer as to how the re-clocking of the DDC works in conjunction with my DAC. Does the re-clocking of the DDC override the re-clocking of my DAC with an i2S connection, or does it just feed my DAC a cleaner signal that allows my DAC to work better and more efficiently given its own re-clocking abilities?  Am I subject to the re-clocking of my DDC alone or is it a combo of my DAC and the DDC working together with an i2S connection?  Thanks for any thoughts and experience!

soix

@lordmelton My source is an iFi Zen Stream that I quite like for the price.  So, from what you’re saying, my Musician Pegasus DAC clock is still working with the i2S connection?  That’s really what I’m trying to nail down here, and after doing a pretty thorough search I couldn’t find a straight answer to this fairly simple question.  Argh. 

@soix 

In your test with the Iris added into the chain from your streamer to dac are you saying that the resulting signal sounded better over I2S than it did with SPDIF or USB when coming from the Iris? I would think that all outputs from the Iris would be equally as good with respect to the improvement in clocking.

@lordmelton is correct in stating that the clock in your Pegasus is still performing with the Iris connected. If you heard an improvement in signal quality it would lead me to believe that 1) the clock in the Iris does a better job than that of the Pegasus 2) it’s possibly the combination of both working together that has produced the difference. I’ve read threads on signal clocking where the owner used two Mutec reclocking units in a daisy chain prior to a dac and claimed there were large improvements in the audible result. 
 

I2s and Ethernet inputs on the better dacs are superior sounding compared to the other inputs, even if you include all the hacks/tweaks that people apply to some of those protocols.

I would take an fpga based dac over a pure hardware dac for many reasons and I have. I got new firmware every 6 months that improved the sq for free. I also got new firmware that doubled the dsd up sampling as well as implementing MQA, again for free.

I have friends that have dacs costing 5 digits that have to pay thousands to upgrade for MQA and these dacs can’t improve their sq so they become out of date.

@designsfx To be honest, I haven’t yet tried the SPDIF out from the Iris because I went right to the i2S connection.  I recently significantly upgraded my SPDIF digital cable so I’ll have to do a comparison and I’ll get back with my results.  My guess is that even using a $4, 6” Monoprice HDMI cable over i2S is gonna be a high hurdle for SPDIF to surpass even with a $660 SPDIF digital cable, but it’ll be interesting to see/hear. 

@soix Before you connected the Iris your DAC’s USB input and card most likely took over processing duties from your Zen.

However that is not possible with the Iris connected.

As i said earlier the Iris is not a clock, it’s a re-clocker, so it re-clocks the incoming USB signal from the Zen and passes that cleaner signal to the DAC.

I2s will generally sound better because it’s far less prone to jitter than other digital connections. RJ45 will probably sound better than HDMI.

Please remember this is USB being converting to I2s so although it’ll sound good it’s never going to sound as good as native I2s direct from a source component, streamer, CD/SACD etc.