@decooney - I think part of it is simply my comparison to the Gryphon solid state amp. : -) The CJ/LTA combo is very, very good. I am just wondering if I could make it better.
Good, agree - no particular cable-length issues, and its good you have the Clear ICs.
As for tube combinations - I suspect you might have a little extra richness goodness going on combining the Amperex small signal tubes with the new-reissue Mullard EL34 power tubes together. I have various new re-issue Mullard’s and they all tilt more to the rich midrange and veiled over top end vs the more clarity detailed side like others can have. fyi, one of the known headphone reviewers out there just re-compared the new re-issue (extra rich) Mullard EL34s to the new (more transparent) Ray EL34s tubes [for example]. He felt the Rays were more resolving on the top end, more balanced, with more clarity and nuance - comparatively. You could ask others on the CJ forums about various EL34s there too in your 120 amp.
A few colleagues of my own over the past year recently had a similar concern, even after trying better cables, and we discussed replacing the re-issue EL34s with new re-issue Gold Lyon KT77s to open things up a little more. And/or the new Ray Tubes EL34 Select, or new PSVane Horizon Series EL34s could work too. Its worked for others. You can check with your amp. Ask those guys on the CJ forum too. I was chatting with members there when I jumped back into KT120s, it helped.
Syrup + added Syrup = more syrup, fwiw. Sometimes it can be too much of a good thing is what many might share.
Note I can also go install any of the new-reissue small signal Mullard’s in my amps right now and this also makes for more rich and veiled over top end with less transparency in my amps, even when biased precisely.
I don’t know that jumping to Cardas Clear speaker cables [immediately] is the first move I’d make without checking this first. The Cygnus are a tad more grainy and detailed than std Clear being a little smoother to my ear, fwiw. Best of luck.