SP10mk2: OMA Graphite plinth vs.Dobbins plinth

has anyone ever tried the Comback Harmonix mats?

 Dear Raul, the mat on my star sapphire series 3 was most assuredly the original felt mat. Perhaps the dealer glued it to the platter before he sold it to me, but for whatever reason it was glued to the mat, and the surface was a felt like material. Just for your information, it was only later, when I acquired much better sounding turn tables, that I discovered how muffled and recessed was the sound coming from the star sapphire, meaning no disrespect to current SOTA turntables. Even with vacuum applied.   The experience did not leave me believing that there was anything special about the mat on that turntable, except possibly that it was especially responsible for the unsatisfactory results. My next turn table was a Nottingham analog hyperspace. It ran rings around the star sapphire in every way. Even more so after I acquired a regulated power supply to supply AC to the Nottingham.

@best-groove I used a common copper cleaning product and an old toothbrush because the mat is not exactly smooth but has micro grooves like vinyls
I insisted a lot and performed more passes but in the end the result was excellent.

After polishing, with a spray I gave a couple of light shredded transparent varnish.

Here is another copper cleaning spray
https://www.flitz.com/brass-copper-tarnish-remover/ 

Has anyone tried upgrading the power cord of the SP-10 mk2 power supply ? It comes with a thin captive lead. Changing it needs some work. Before I try that I would like to ensure that it really brings an improvement

@pani A reliable audiophile friend of mine installed an IEC inlet in the SP-10 Mk2 PS and tried several high end PCs.  No difference.