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

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.

Mjpflieger, the Jolida 302A/B is set up for the EL34 only. It cannot use the larger 6550/KT88/KT90 tubes in stock form. Conversely, the Jolida 502 cannot run the EL34/6CA7 as things are.

However, modification can be done to either so that they can run the other set of tube, or run all of the spectrum.

And, for what it's worth, to my ears, the Jolida 302A/B is sonically far and away the winner over the 502.