Tube amps for classical music FU29 vs EL34

I'm not familuar with the sound of different tubes/tube amps. I have a a Jadis intergrated has 4 KT90's, and has a good sound, but the speakers limit the amp. Soon to be rectified, new speakers with a 87db rating late this summer. But I'd like to get another amp for primary system, keep the Jadis for a second system. I'm looking at 2 tube amps, one has 4 EL34's the other 4FU29's, both intergrated amps. I'm guessing the EL's will sound like the KT90's, and have more bass end. But with classical, I can forgo some "punch". The FU's look like it may offer more complexity in the mids, for orchestration and vocals/opera. Right track?
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
Its FU29, not 4FU. The 300B is a single ended amp, so requires a sensitive db rating 92+ speaker. That part I understand from experience. The FU29 amp, Cayin 500, I'm not sure what kind of amp it is. Also does anyone know if the Cayin 734 will accept KT's?
Hello Bartokfan. I can concurr with M wilson's experience regarding bass response with both the el-34 and KT-88/6550 tubes. Grgm's solid advice on waiting until you get your speakers is a very astute piece of advise.Depending on your room size of course???? will more than likely need a little more muscle,especially considering your speakers nominal impedence of 4 ohms. The jadis amplifiers are one of a handful of tube amplifiers that seem to respond well to a speaker with a low impedence due to there excellent output transformers and a 2 ohm tap.Most typical el-34 based tube amps will have a tougher time with 4 ohm load.The only el-34 equivalent tube that will give you the bass foundation and slam of a kt-88 is the original Genelec KT-77. The el-34 tube is a power pentode whereby the Kt-77 is a beam power tube like the kt-88 and can be succesfully substituted for an el-34 providing the screen-grid ratings of an el-34 are observed.Unfortunately... the Kt-77 is very scarce and typically very very expensive.Sonically.... the Kt-77 is a truly amazing tube when optimized in an el-34 circuit.It is even more liquid in the mids than a good nos mullard el-34 but possess's the bass drive and resolution of the Kt-88.The top end response of the Kt-77 is second to none and will easily trump any kt-88 or kt-90[genelec kt-88's included] Caveat....Using a kt-77 in a el-34 circuit will "not" give you any more power than an el-34. Best of luck on your endevour. Cheers David
Think of the KT90 as a 'heavy duty' EL34. A KT88/KT90 tube will have more bass than an EL34, as others have mentioned. They will also have more power, FWIW.
Interesting post David. What I was refering to in the EL34's is that they provide more bass than my friends single ended 300B Cayin(can't recall the tubes), which classical music sounded flat, IOW lacked a certain depth and height I'm looking for in an amp. So yes, I should get the speakers first, see how the Jadis responds. The Jadis lacks the deeper bass regions. My current speakers are 25 year old Philips 2 ways. Paper 8 inch cone, beautiful clear dome tweet. You hit on something about Jadis' transformers, the quality. IOW all transformers are NOT equal. And since this will be my "last amp" (notice I have the Philips for 25 years)I want to make it count. I don't make enough $ to trade off ,like you guys can. So ,seems its back to my orginal idea, a Jadis DA30/used, if business is good, new, sometime late 2005. The DA30 has KT88's. I'm sticking to my orginal plan, just got sidetraked alittle.
Aroc's post further confirms to stay on course with the Jadis DA30/KT88's. You see most of classical collection 400+ cds are not DDD/modern recordings. Some are from the 50's, some are Naxos, and others just don't have much dynamics. But still want to get all the music on a solid foundation = bass. I realize from listening to my friends 300B, big bass rolloff, that w/o a bass foundation, classical sounds flat. But as I say, listening to jazz vocals, the sound was "super-natural", but the slight bark in the male vocal threw me off. First time I heard a liquid smooth mid, but for those who like a "kick" in bass, will have fatique of a 300B amp. Another friend has a pr of old Conrad Johnson tube monos with Martin Logans, I believe Arius, again too flat. I'm really hoping the Seas Thor sounds alot better than these old smoky sounding Philips, I'm ready for a new experience. And then to take that experice even one step up to the DA30. My final system. I'll keep everyone posted as to the new Thor's. I use to post here a few yrs ago under the name tweekerman. I promised everyone I'd have new Thors,...well I'm finally close, good chance in July.
Hi Bartokfan. I believe you can also run an el-34 in the Jadis da 30 as well as the kt-90, although you will certainly have to re-bias the output tubes to do this. Biasing any Jadis amplifier is a bit of an exercise as they are not the easiest amp to rebias.None the less, any Jadis amplifier is an incredibly musical instrument and most certainly a very expensive proposition to better.While I have never heard the Kalin in my own rig...I find it difficult to believe it would better the Jadis no matter what the tube choice may be. Best of luck.
Personally, I wouldn't get too anal about the supposed differences between EL34's and KT90's (or 88's, or 6550's). IMHO its far more about the design of the amplifier these tubes are used in. One of the limiting factor of EL34's is that they produce roughly half the power of a KT90. Typically, an amp with 4 KT90's per channel will produce about 150 watts +/- and one with 4 EL34's will produce 75 watts +/-. Once you have picked an amp which will drive your speakers properly you can fine tune its sound by tube selection, and you will find differences between the types being discussed. FWIW in an amp which is designed to accept both EL34's and KT88's, KT90's and 6550's, I would agree with the general statement that the EL34's will have the smoothest midrange and sound weakest in the bass. The 6550's the most neutral, the KT90's the more "detailed" and the KT88's (which I use) a tad warmer and more airy than the former. But it all depends on the amp and, to a great extent on the small tubes used as well in conjunction with the power tubes.
On second thought, I may want to go with the DA60, since it will be my "last" amp, the DA30 has 4 Kt90's, which is exactly what my Orch Reference has, so thats not a step up enough. The Da60 although 2X's the price of a 30, has 8! KT90's, thus giving me a lifetime of excitment.
Hello Again Bartokfan. Yes, the Da 60 would be the logical choice for your speakers and must be considered one of the finest sounding integrated's on the planet by anyones standards.It can also be optimized for the el-34,kt-77,kt-88 and kt-90. PS: there is a Da-60 presently for sale here on the Gon for a song,a no brainer at $2600!
Your speakers, simply put, are NOT tube friendly. 87db just doesn't cut it. If you want some strong, tight bass at reasonable volumes, you should consider at least 90db speakers if not more.
Your EL34 amp is probably 40 watts. To drive your speakers to 90db takes double the wattage. This really adds up:
1 watt = 87db
2 watts = 90db
4 watts = 93db
Your 40 watt amp on 87db speakers will net you approximately 103db. If you had a pair of 94db speakers, the same amps would produce approximately 110db. Rule of thumb is you double your "perceived" volume for every 10db increase.
Also, keep in mind that bass uses the bulk of the power. So, if bass is an issue, you should be looking at something like 100watt amps.
IMHO, the best setup I've ever heard with classical music came from lower power amp with coxial speakers.
I heard this setup while walking around in Akihabara "The electronic town" in Tokyo back in 1998. These Jensen imperials are the best by far. The depth and with of sound stage is amazing.

I've heard B&W nautilus 801s with Nakamichi Nero ( propane tank shape ) amp and it was very good too. However, it is still sounded "aritificial" when compared to the old Jensens.

You'll only realize the difference once you hear them.

Happy listening
As I remeber Jadis used KT-88's in the origional amps and they pushed the hell out of the tube, thats why the Chinese KT-88 did not hold up since it was really rated for 35 watts plate dispation and the screen was 4 watts.
The best choice of tube would be the JJ-KT-88 or the winged C KT-88 true Svetlana not the new sensor KT-88 that says Svetlana.
EL-43 is a great tube but at best its a 25 watt tube and the screen disapation is really not rated for the power pushed in Jadis since its ultra linear tap, although a 1k- 2 watt reaistor could be inserted on pin 4 for the screen tap.
this will take the heat off the screen of the EL-34's, KT-90 was molded around sweep tube design, but has a screen voltage increase so it could be run ultra linear screen tap configuration rather than most sweep tubes running 250 volts max screen.
KT-77 is a good tube but where can you find them now I sold my stock of 10 NOS KT-77's years ago and I find the 6CA7 to be equal to the KT-77 and Groove tubes has a nice American 6CA7-GE worth looking at.
i am running a fu29 4 tube Cayun 590 thru some antique Maggie 2a's(which i rebuilt) and with great results. i have been through numerous amps including a Classe' DR 10 (transistor) and other EL34 amps.i have never seen such tubes and immeditelly put the cage back on when i viewed them!Sorry but this fu29 amp blows everything out of the state! and with clarity. i am not a hard rock guy but these tubes seem to fit the bill for all tastes.
You can run most any everyday non triode output tube in the JOR, beyond the 6L6 variety.

KT90 is the most powerful. EL34 sound much different (softer) and less powerful, though there is no penalty in terms of life, and the standard Orchestra uses this tube. KT88 are not run hard, as the amp is not autobias, and must be set for the tube. In fact, the bias settings are much on the conservative side, and my experience is a set of tubes should easily last 5 years (I got 7 on the KT90, with A LOT of playing), which is far more than the normal two years most high end tube amp manufacturers suggest.
re: my entry of 10-05-04
the amp is a cayin 590 not cajun. sorry. it has 6ohm outputs which may explain it's smothness with my older Magnaplaners. the fu29 tube is far superior in clarity for any music source than my previous el34 based amp.