Platter mat insanity

@noromance ,

Your last approach, the brass screw heads, may be similar to Pierre Spray’s mat with teeny brass points? Also, are you, or anyone else posting here, using a weight or clamp in your testing?

@terry9 ,

Although I haven’t looked to see if you have a virtual system, I was wondering about your 1" graphite mat. Does this mean, the spindle doesn’t protrude from top of the mat?

@slaw 

I use a custom spindle for the air bushing (thrust and radial air bearing), which supports a cast iron platter and the graphite mat on a machined stainless taper. Part of the design is an extension of appropriate length to serve as a record-centering spindle. I daresay an extension could be made to accommodate any TT for a few hundred - but it does need precision machining.

The reason for a two-piece spindle is simply experimental uncertainty - I didn't know what would work. By itself the cast iron rang, by itself the graphite rang, but together on the spindle they are as physically dead as Archimedes.

@terry9 ,

OK..you just blew my mind!

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.