Effect of Marigo clear transformation and Audioengr Synchromesh ?

The two items you describe serve completely different proposes and as such are complementary. I would not be without the Marigo mat in my pretty high end (dCS Vivaldi stack) system and I also have a complex clocking setup which brings benefits as well (I don’t use USB so the synchromesh is not relevant). 

Id suspect the impact of the reclocker will be more substantial but in my opinion both are well worth trying

What is your digital setup? If you are only using a CDP, then you would not need a SynchroMesh. This device is used between a transport and a DAC or a computer/server connected to a DAC. It reclocks the data stream to reduce jitter and improve performance of digital audio.

Like folkfreak, I use a Marigo Audio CD mat and wouldn't be without either. It  helps take the "digital" edge off of CDs making them sound more like analog.

Thank you all, I think it’s the cd mat t,will apply on my set up.....