Note that I am aware that some might want to go farther
afield with cost no object components and others may balk at the significant
cost of my choices. My vision is to find affordable solutions that reach the
next performance / cost plateau.
I will add that I think Tom Thiel’s choices are *very*
sensible. The upgrades will almost certainly (can’t say for certain ‘til we
listen!) yield a significant SQ improvement but without going beyond the budget
of most serious listeners.
Left to my own devices, my choices would have been similar
to Tom’s in some ways. I was honing in on a solution that would have added a
substantial (30%) Clarity CMR bypass to CSA coax feeds. This would have been
more expensive and not necessarily overall better than what Tom outlined. In
his research, Tom has learned that certain bypass practices can have detrimental
effects! Elsewhere, I was going to add small polypropylene bypasses to the
extant caps. Tom’s solution is far better, replacing the electrolytics in the
shunts with the custom 160V PPs. We are fortunate that Tom is able to work with
Clarity to have this cap made to spec. An off-the-shelf solution would be very
expensive and with ginormous caps that would be very difficult to fit.
These upgrades will not be inexpensive ($TBD). All XO parts
are replaced - most caps are custom - except for Thiel’s custom 1 uF bypasses
and the coils. As I wrote earlier, if I were to replace my CS2.4SE with
something new I would start at something like a Vandy Quatro or Vivid B1; $15K
speakers! After these upgrades, I suspect such a search would have to reach to
something like the Vandy 5 Carbon, a $30K speaker. In other words, the CS2.4 is
a seriously good speaker in stock form and optimizing its crossover should
elevate its performance to the next tier (or beyond). Do I want to live with a
speaker whose neutrality, transparency, and resolution exceed or rival anything
up to $30K? And for the “only” cost of the upgrade? Hmmm, decisions,
decisions ;^)
As Tom wrote, some owners may want to go even further.
Earlier I linked to Jim Smith’s outboard XO for his Avantgardes featuring a
rack of Dueland caps and resistors. Would that approach outperform what Tom Thiel
has outlined? I hope so – that’s at least $20K in parts! But we’d have to
listen to know for sure. To my thinking (and budget) that is not sensible for a
CS2.4. Maybe you CS3.7 and 7.2 owners will choose to push the limits? But
remember that Tom Thiel’s “base” upgrade is a notable upgrade even for those
models.
later production 3.7s have Chinese made crossovers which
seem to have some polyester caps where polypropylenes are specified. And those
are built on printed circuit boards
My SEs also are on PCBs and with some MKT caps where Jim
Thiel’s schematic specified PP. My pair was built in 2012 (the year Kathy
Gornik sold Thiel Audio) and are among the last SEs built. @jafant I suspect
your pair are similarly equipped. For us, Tom Thiel’s upgrade will probably be
an even bigger jump in SQ than for owners of earlier SEs.
