Platter mat insanity


I was doing an idler upgrade to my 401 (more anon) and when finished used the Keystrobe disk to ensure speed. I use a 10" EP as a platter mat. I played a bunch of albums and it sounded fantastic. On the 6th side, I noticed I'd forgot to remove the 4" strobe disc. Duh. I took it off and figured VTA was responsible. So I lowered the arm to see if that made it sound so good. Nope. Put back on the 4" strobe disk and raised arm. The awesome sound returned. So air under the record removed haze, smearing, flattened soundstage and muddled bass; and made it so more musical. Comments... 
128x128noromance
If the platter rings when you strike it with something don’t strike it while music is playing. Even better isolate the table. Then the platter won’t ring.
@slaw I can't find any info on Sprey's mat. I may try mounting the brass screws to a disk. I don't use clamps as I find they deaden the sound slightly.
@slaw Thanks. 
The actual link is here.
Interesting 5 dot support on small mat with a brass? weight.
I believe this mechanism, like my own efforts above, to yield cleaner reproduction. It may not suit all recordings but it excels on those that do.