What is the difference between the JJ EL34 type power tubes?

JJ has an EL34, E34L, and KT77, and I would like to know differences tonally.
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gear in profile
I just put E34Ls into my Windsor head. They are more punchier and crisper than the regular EL34s.
Were the regular EL34's JJ brand?
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gear in profile
the E34L is a military version or sumthing, dats what i read on a tube shop site
It depends on the amp circuit, I think, as to how it affects your tone...And they usually have to rebias your amp if you're changing tube types. It's not just a plug and play operation.

I have KT77's in my YCV40, it made it more British (it used to have 6L6's) and has a nice low end, and a nice mid-range crunch.
From Eurotubes:

JJ EL34: This tube is as close to an NOS Mullard as you can get although I have to given mention to the Svetlana EL34 which is close, it’s very good but I like the way the JJ tubes break up better. They are very smooth and have the biggest low end of any current production EL34. I still prefer the JJ E34L for most applications simply because of it's extended low end and the fact that it's tighter and punchier.

JJ E34L:This tube has all the tonal qualities of the JJ EL34 but it has an extended low end response and is a little punchier and more aggresive so I use these in all Marshall, Mesa, Carvin and just about any high gain guitar amps.

JJ KT77:A truly beautiful reproduction of the original KT77 that will run in place of any EL34 type tube. A little bigger low end with a great chunk and a nice sizzle on the top end. The breakup is smooth and a bit less aggressive than the E34L's. An amazing tube for both guitar amps and Hifi.

They're all a EL34 type, but with different tones.
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