Tube amps for classical music FU29 vs EL34

EL34's with more bass than KT90? That would seem unlikely, based on my experiences, and a bit of conjecture: As compared to KT90 (taking KT88 as my reference... KT90 is a derivative of the KT88) - what I can offer is that every KT88 I've heard has vastly out-bassed every EL34 I've heard. EL34s are famous for mids, which they have in spades. I find them noticeably lighter in bass regions than KT88s. KT88 has great bass, good mids, and great highs - if anything, the KT88 is pretty well balanced in my experience, from low-to-high. The EL34 *is* an octal tube with similar operating requirements, so it's a drop-in replacement with many (but not all) amps that take KT88 and KT90, but it's not really a next-door neighbor of those tubes, soundwise.

I've not heard of 4FU29 tubes.

Based on your listening preference, you may indeed quite like the EL34s. They're *the* midrange tube for many listeners... but they give up some ground to KT88/KT90/6550 in the lower frequencies.

I agree with Mwilson above. To add to sound characteristics, the generic EL34 is usually more "neutral" than the 6550 (that's warmer). I don't know the FU29.
OTOH, I'm not sure about getting away with 2xEL34/channel...
For classical, you need detail and dynamic capabilities and energy. Room acoustics aside, speaker specs should be considered carefully: yr 87db spkrs will give a nominal ~70-75 db at listening position. A ~45W/channel amp should yield (nominal again) ~16db (spl) swings from 1W before clipping...
i.e. ~86-90db at listening position before clipping. Not much!
I'd suggest more efficient spkrs for the amps under consideration.
Finally, a side question: why relegate the Jadis to a 2nd system? Is it the Orchestra? It's a good amp, and expensive to improve upon! (IMO, etc)

So the KT88/90's are a good balanced tube, which oust the EL34. I'll have to ck to see if the amp has the ability to take different tubes. But that may not be the solution. Obviously the amp will still have a certain "flavor" no matter which tube. So the better thing would be to A/B the EL amp with the FU amp. Which I do not have access to.. My friend had a single ended 300B with the Silverline 4 way speaker/db93,high sensitivity. I just found classical orchestra to lack some depth, and that might be from the lack of the octaves in the lower bass region. But the sound on jazz was superclean, except the male voice has a slight bark/wooden sound in certain octaves. The Jadis Orch/Ref is a good amp, I'm just ready to move on to another bigger amp.(the other amp/Cayin EL @ $1400, Cayin FU @ ,guessing ....ah could be out my price range). So the EL is about the same/less than the $2100 Jadis/new. BTW, I can't read specs, nor the elemental tech stuff, kindly posted from Greg. The speakers I plan to get are the Seas Thor/4 ohm speaker. The Cabasse MTM's are much higher efficiency, but I must have the Seas' tweeter in my system, so the amp has to be chosen around the speaker, not the other way.

Considering the Thor's impedance curves, it would look like a stronger (than ~40W) tube amp is needed. I would wait to get the speakers and try them out using the existing Jadis as a reference point. Cheers