Well, I think since Eb's in general is less popular, not as much research and development, ie time and money is devoted towards them. Similar to how many American tuba manufacturers in the past didn't and for the one that remains still don't make as many CC tubas. And at times do not want to devote the proper resources to make sure the CC version is the best it could possibly be.
For example the King 1293 rotary Monster CC uses a 0.687 bore instead of the 0.750 like it's BBb sibling. And many people say the BBb version is waaay better, night and day different.
https://simonettitubacollection.com/ins ... y-ca-1936/
Or as discussed in the past when Conn used to make the 52j (18" bell), 54j (19" bell), and 56j (20" bell) CC tuba. Eastmon was willing to put more effort to make it closer to the better prototype that Matt Walters made.
Plus, 4/4 BBb's and CC's already fill the void well enough for a super large Eb or even F tubas to take that place.
@donn I do agree that bigger isn't always better.
But York took the time to figure out how to make a nice 6/4 CC, even when BBb's where all the rage and better thanks to years of R&D. Heck, Yorks large Eb's were also "better" than most too, ie the Kanstul.
I'm sure some of 6/4 factory Martin CC's where nice too, but I guess the York was better or more desirable. A little sad that York folded before the desire for their tubas exploded.
At least Wessex is/was willing to make a good 6/4 Eb tuba. If Wessex can stretch their R&D a little bit more just to figure out why the 4th valve doesn't respond as nicely like 1 and 3 combo I think they'd have something super spectacular. Assuming nothing gets ruined by altering the 4 valve tubing or bore etc.
Even though I've mentioned I don't want to get a horn made in China, the 6/4 Wessex would be an exception. But alas, the B&S 4097 CC (pt20) will be filling that spot plus I'm not made of money.
And... I am curious about other tuba manufacturers like Gronitz, Thein, and HS MUSUCAL from Brazil are doing...
EDIT: Well maybe York just figured out how to make a better large Eb then everyone else. Unlike my long explanation of CC tubas not receiving as much attention to detail like BBb tubas were.