The Quadratic MC-1 is made from customized Cinemag transformers as well, and as I was told, it is not the same as the Bob's Devices blue cinemags. Some feel the custom Cinemags in the Quadratic are higher performing above the Bob's Devices Sky 40 (blue cinemags). Knowing this, it might not be fair to assume that because Jena Labs contains Cinemags, that it is similar to Bob's Devices Cinemags in performance. The Jena Labs web site states that it has custom made transformers made by Cinemag, and so, then a comparison to the Bob's Devices may not be telling of the true sound quality of the Jena.
I own an EAR 834p. In my experience, adding an external SUT to bypass the internal SUT if you are running a moving coil cartridge has yielded a much better sound. I think the internal EAR 834p transformers are merely good but can be easily bettered by spending less than $1000 on a SUT. I have a Bob's Devices Sky 40. It is excellent. I also use a Phasemation SUT. I far prefer the Phasemation. IMO it better the Sky 40 in almost everything but most important was projection, body of instruments, tone, and dynamics. Far better in my system. I think the Phasemation T-550 is a relatively unknown gem.