Hey Keith,
how's it going? Trust all is well at your end of the woods.
comparing the 845 to this tube, I heard it at the Melbourne HiFi show few weekends back, driving a pair of Avant Garde Duo omega's, fabulous sound. To me it was very hard to tell the difference, if any I was probably focused on the sheer power and dynamics of the 833. The sound off the Duo's was of course massive, very big/large sounding, not to my liking though, that typical massive accelerated wave of horn punch. Whether one would prefer the 845 in many reasons similar to what is used on the awesome Kondo amps- Kogaru's, would need to be closely investigated with dedicated listening environments.
I remember back in the day, a pair of Apogee's driven tri-amped with a Kondo Audio Note Ongaku I's- that was simply spectacular and even at the time for a equally spectacular price... To compare the 833 directly against the 845, I would only recommend trying them out on your system, or perhaps try to check if the dealer has an amp with 845 and compare directly. What we my state here is only a guideline, only your ears can be the ultimate judge.
I remember many of my fellow audio enthusiasts say push pull ultra linear was far more dynamic compared to SE, and that the 300B is no match for a pair of KT120's. Well right now I'm using a simple 8w/ch SE 300B on my Quads, and I'm not missing anything from UL push-pull, infact to me the 300B's musicality with stats is superb! Therefore, different set of ears = varied preferences.
I'm not sure what brand the 833 amps were but they look identical to your photo and the finish, perhaps they were from AM. The sound coming off the AV- Duo's was effortless and all I can say is that it was quite impressive.
By the way, what are you doing with the Cary's? Nick has folded up and gone fishing, hence don't know who can service these in Melb...
Have a good one and all the best in your quest. When you have them finally set up, perhaps I would like to come over for a listen.
Cheers mate, RJ