EL 34 vs. KT 88 ---- What's the difference?

I think Biomimetic makes a most excellent point regarding the comparison in saying, "the overall power curve is flatter with KT88's than EL34's." However, perhaps I am wrong, but I thought the Manley Stingray ran the EL84 tube, which is a whole 'nother kettle of fish, yet not my cup of tea...

The comment I want to discuss is the EL34 midrange, which I believe is where the tube shines, as many have commented. I want to make the distinction that the term "rich" should not be taken as warm, euphonic, etc. Rather, in my experience, it is the openess and truth of tonality that sets the midrange of the EL34 apart from anything else, tube or solid state. The most concise way I can put it is that when used in a sympathetic system, it sounds simply "right". The EL34's midrange can, in the best of circumstances, make me thing that nothing else sounds as real. It's sounds like music. In one amp I owned it was flat out breathtaking - NEVER heard notes come across so perfectly.

The converse is that in the wrong application or system the tube can really come across as bright and harsh.

The 6550 and KT88 bass certainly takes at least two steps forward from an EL34. The KT88 can produce an intoxicating mid - upper bass warmth/fatness that I tend to run towards. Those who prefer the RCA 6SN7, as I do, will more or less know where I am going with this. The 6550 doesn't really do that, it more level headed in this region. It's right here that I have a hard time NOT running the KT88 in my amps. Perhaps, it's my favorite place in the musical spectrum?

The 6550 and KT88 tubes often will sound more extended in the highs, though I will make the case that sometimes, the treble that the EL34 does produce can be superior in its clarity.

As also stated, power is significantly less, but how your system manifests this may or may not be directly proportional. On one amp that I ran, the step up in volume I needed to make was only a click or two. On another, it was the difference between being able to run in triode (the 6550/KT88/KT90) versus HAVING to run in pentode (the EL34).

The 6550 sounds the most even handed to me, yet also the most boring in many applications. The KT90 sounds kind of cold and uninspiring in the mids, though it is a most robust tube if one is looking for long life. Many folks feel the 6CA7 is superior to all, combining a fair amount of the bass richness/fatness of the bigger tubes, with a better midrange than they can produce. I am aiming to audition the Ei 6CA7 this fall in my Jadis. Which do I prefer at this point? Well, call me one afraid to take a definitive side here, but I keep going back in my amps between the JJ KT88 and Blue Glass E34L.

There is a very clear difference in the way these tubes sound. I have no idea whatsoever what the differences are in terms of construction etc. The EL 34 is known as the queen of the mid-range for good reason (I don't know the king) it clearly excels in producing a certain full and yet sweet sounding midrange it rolls off the top end a bit and tends to loose control of the bass but both end of the spectrum are reasonably pleasant. The KT-88 produces a more robust powerful sound especially at the extremes of the frequency spectrum. The mid range is there but it tends to be clinical sounding and less musical. The KT-88 is simply a bigger sounding tube and it will rock you, its just not going to be as polite sounding as the EL-34. I really like it for some types of music and it won't struggle producing tighter bass and sparkling treble. I hope that helps.

I found this thread to be very helpful... thanks to all. I currently use a Jolida 302A with B&W DM602 speakers, Audioquest Slate bi-wired cables. I find that the EL34s in the Jolida are sweet for jazz, classical, and voice but lacking a bit in precision for rock, which I still listen to very frequently. I'm just starting the process of tube rolling, so all help is appreciated for this novice.

From what I've read, if the KT-88s are compatible with my amp, I might try those for rock music. Yes? Dangers?

You are thinking of rolling KT-88s and EL34s? Perhaps I am missing something but I did not know this could be done at random.

I will say that Svetlana KT-88s in my McIntosh 2102 amp has made this amp sound as good as any in its price range and better than many more expensive amps.

Yes - I agree with the statement KT88's are less polite. I listen to a lot of rock. The point I was making is about the Manley being based on EL34 - however, it is a good rocking out amp. I was just saying that it is a more polite tube by construction, though it can certainly find it's way through any kind of job depending on how the amp is engineered overall. My understanding is the KT88 just has a bigger plate and uses power more efficiently so it has a flatter response. But look at triode sounding great - efficiency isn't everything. Plus, what kind of tube, what kind of capacitor, plus point to point wiring versus boards, plus linearity of layout... there are a host of factors other than just tubes. Everyone is so gung ho about the KT88 here - I am too, I use them, but I thought it might be good to illustrate the other side by finding an amp that wasn't quite so warm and fuzzy with the EL34, while still being hyper ... "musical" for lack of a better term.