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

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.

Wow, it takes a person of real character to return to make a correction to an earlier statement. You have won a lot of admiration from me, Biominitic!

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.

My Granite monoblocks took both the KT88 and EL34. I could never get them to sound right with the EL34, and am pretty sure it was an issue of bias, though I didn't pursue it too much.

My Jadis DA30 and DA60 integrateds can also use either, and I strongly prefer the EL34 in both of them, provided the right driver tubes are used to address the loss in low frequencies that occurs otherwise. In a nutshell, the EL34 really walks away from the KT88 in the midrange, giving both amps a far more musical and natural presentation.