Here's what I've tried:
SED WINGED =C=
I used to think these were made of tits and honey and shit. Mostly because everyone else said they sounded great. I used them for years in my Diezel VH4, Ceriatone Chupacabra, Cameron CCV, and I tried them in my Peters Hydra. Obviously, the same tubes are going to sound different depending on the amp. But for the most part, these are pretty good. Kind of a heavy, greasy mid-range. Like eating a Philly Cheese Steak covered in p'tater tots and mozzarella sticks. Lows are a little loose/bouncy/flubby at times, probs from all the cholesterol. Highs aren't harsh. Kind of swirly. Throw them in a mid-heavy, harsh high-end amp like a Marshall and you get instant rock and/or metal depending on the amp model and boost. After trying a few other tubes, these are no longer my favorite though. Also, bias on these tubes over the last year or so (on many sets that I've used) has drifted all over the place in every amp I've used. Quality is shit. Especially now that SED is no longer around. I had a pair red plate in my Einstein a few months ago. They were like 2 months old at the time.
ELECTRO HARMONIX
These actually surprised me. I have them in my Peters Hydra at the moment. The bias is always rock solid. Low end is tighter than the SEDs. Highs are nice and articulate. Mid range isn't as greasy/smeared. Just a balanced all-around tube for a good price. Nothing stands out about them. But nothing really that bad, either. No complaints yet.
RUBY BSTR and BHT
I can't remember which was which. I've tried them both. I think the BSTR was the one that resembled a 6L6 sort of. Increased lows and highs. Glassy in the highs. But too much for my taste. If I wanted a 6L6 I'd just go buy some and shoot myself because 6L6s suck. I think the BHTs were the ones that can handle crazy high voltages/current like the SEDs. Or maybe it was the other way around. Either way, neither of these two versions gave me a tonal boner. So I dumped them. They're pretty clear, non-descript sounding tubes though.
JJ E34L
Can't remember. Had them in my Uberschall. I think they had a tighter low-end. And more headroom than other tubes. Other than that, they were pretty good. Maybe a little nondescript.
JJ KT77
Another one that's a bit of a mix between an EL34 and 6L6. But more mids than the other tubes listed above. Tighter lows. Highs on the JJs are a little subdued. These sound meaty and mighty and other words that start with M. Quality is pretty crappy though. Flakes of mica floating around inside the tube. Bias that doesn't hold. But they sound pretty good. Nothing like a 6L6, even though I just said they resemble them. They just have the dynamic range of a 6L6 in terms of low end through to the highs. Yeah that's right, this tube is a fucking contradiction. Sounds good in my Diezel.
GOLD LION KT77
Not as thick or wide sounding as the JJs. But a more aggressive, snarly, pissed off mid range. High end is a tiny bit harsher-slash-kinda-glassy. I can't tell if the low end is tighter or looser than the JJs because I'm half deaf from rocking this bad boys. But definitely tighter than any EL34 I've tried. They can get a little gritty/grainy though if you're not careful. Careful of what, you ask? I don't know. Just watch yo'self. These tubes are pretty awesome, though. Probably a good replacement for the SEDs now.
RFT/SIEMENS EL34
I really want to try these. Anybody have experience with them?
