Tube Anchors
I recently tried the Mapleshade brass tube dampers and need to share this with you.
#1 Even though a 5687 datasheet calls for .875 dia max tube and Mapleshade sells a .875 dia max tube anchor, that
IS NOT a fit. The anchor diameter is just barely too large for the tube. I shimmed mine with high purity, ultra-thin, aluminum strips sourced from a local super market.

If you buy these, call Mapleshade first or just try the next smaller size.
#2 One feature of these is a shielding ground strap. There is no convenient grounding screw near the tube CCA. But you can route it outside to one of the RCA mounts and capture it there.
#3 They did work as advertised. More detail yet added warmth too.