N_Cook Inscribed thus:

I had to get inside that amp again, yet another PbF problem from next
to zero insertion force speaker connector at the PA 4 removal &
inserts by me was enough , only 6 months old.
The slabs pass red laser pointer light, but then on checking but so
does the ceramic of high temp "choc block".
These slabs are more trnasmissive and scatter the light throughout the
slab not just the entry and exit area of the chock block.

Mmm ! Interesting. I have a small quantity of boxed TO3 BeO
insulators. I'll have to get one out and see.

--
Best Regards:
Baron.