Morbius again with a follow up on my TT mat issue...
I had been using the 2mm thick felt pad suppied with the Rega but found it sounded flat, ergo the search for a options. So I proceeded accordingly...
1st - I tried an older thin, high density rubber pad in place of the Rega felt but it compressed the top end, made the midrange a bit murky and seemed to reduce the dynamics. So on to phase 2...
2nd - I bought a sheet of 3mm cork, sanded it smooth and cut it to fit the platter. Overall, the sonic signature tightened, the image and the bass more defined but it flattened and deadened the sounded. Moving on from there...
3rd - I cut a 1mm sheet of cork to 11.500" and cut out 4" in the center to accomodate record labels, then bonded eight 1.500" x .750" 1mm cork pads equidistanty spaced around the perifery .750" from the outside edge and six .750" x .750" cork pads from the inner edge of the cork disc and placed it on the glass platter. Sonically speaking, it really open up the top end and exaggurated the airiness and tightened the bass, the vocals became a bit edgy and the image became less deep and more vague. Closer, but no cigar. So...
4th - I cut a thin piece of felt (-1mm) to 11.500" that ran from the spindle to the outside of the platter and placed the new cork mat on top. The background became blacker, image depth returned, surface noise less evident, the vocals were tightly focused and the bass regained its' punch, depth and detail and the frequencies are well balanced and great dynamics. I couldn't be more pleased. So my journey has ended (for now).
(By the way, I swapped the Vibracones for carbon fiber cones and the vocals and bass noticably tightened up. Thanks for the tip.)