People will catch on. The JJ KT-77 is the most amazing valve I've ever heard.
It needs 6L6 plate impedance from the OT, and high bias for best tone in my experience. It is a 32 watt tube, not a 25. I believe JJ lowered the stated rating as it was going into EL34 circuits without proper impedance, thus overdissipating the tube into early failure.
It is no surprise it's recommended for the Diezels. It's the voice of God.
This guy saw it:
(from Eurotubes)
Fortunately, I've been blessed with the opportunity to spend more time with the test-batch quad of KT77s that you graciously sold to me. The "official" results and findings are in, and I'll go into more detail below, but all I can say is WOW!
My Hi-Fi stereo is an Antique Sound Lab AQ1003. I just recently purchased this amplifier and was running it with a quad of "hand-me-down" Electro-Harmonix EL34-EHs. My speakers are PSB Image 4Ts. My CD player is an NAD, my turntable is a Music Hall MMF, my cartridge is a Goldring Elan, my phono preamp is a Pro-Ject, and my interconnects and speaker cable are all Audioquest. Not particularly "upper crust" Hi-Fi, but a great sounding system at a reasonable price.
After installing the new JJ KT77s and biasing them to about 35ma, the improvement in every sonic aspect was startling. Immediately, it was clear how much more balanced they are across the frequency spectrum. The bass extends lower than before, but is tighter, punchier, and more natural (i.e. - less boomy) than I've ever heard on a stereo in this so-called budget range (approx $1k). The harmonic richness in the midrange frequencies was just stellar. Instruments not only sounded more life-like dynamically, but harmonically as well. On well-produced albums, this was particularly evident. The treble response that the KT77s added gave me a permanent smile - brass instruments sounded less clamped than before, and again the harmonic richness of things like cymbals was just phenomenal. The background noise with these tubes was non-existent.
At high volume levels, the KT77s never lost their definition or clarity...and fantastically the frequency response remained constant and linear. Whether you listen to primarily orchestral music, jazz, blues, rock, metal, hip-hop...these tubes have the linearity, richness, and headroom to deliver in spades. I will NOT search for a different EL34 for my stereo.
As for guitar, my rig is relatively straight forward. My guitars are two dramatically different PRS's, a Gibson Flying V, and a Fender Eric Johnson Sig Strat. My amplifier is a THD BiValve, and my cabinets are an Avatar open-back 1x12 (w/ Celestion G12H30...used primarily for jazz and blues) and an Avatar closed-back 2x12 (w/ Celestion G12H30 and Vintage 30...used for everything else). My pedal board is a little more complicated, but I feel its irrelevant to the KT77s. Cabling is George L's.
I used eight different preamp tubes for this: 2x JJ ECC83s (120 gain), 2x JJ ECC803S (105-110 gain), 2x JJ ECC81 (120% gain), 2x Mullard CV4024. Power tubes I compared the KT77s to are (I only selected from my EL34-types
Mullard EL34s (Xf2), Matsuhisha "fake Mullard" EL34, Amperex Bugle Boy EL34, JJ E34L, and Electro-Harmonix EL34-EH.
With conviction, all I can say is a resounding WOW!!!! These KT77s are literally my favorite tube that I have of any type, including some of the late greats like the aforementioned or the RCA 6L6GC Black Plate, Brimar 6V6...and the entire line of JJ tubes. Not necessarily that they're better than the other JJ's, they're just more what I'm looking for sonically.
Clean, these tubes have a fantastic deep low-end extension that isn't the least bit boomy, but instead chunky and defined. The midrange is EXTREMELY rich and incredibly musical. The treble frequencies are articulate, glassy, and very very sweet. They worked great for everything from fingerstyle jazz comping, to Strat-toned jazz blues, arpeggiations...everything just jumped out of the speakers with authority and musicality. Lots of sweetness, gobs of harmonic overtones, PERFECT frequency response. Just insane....
Overdriven, the KT77s have probably the coolest crunch of any single tube I have. They have the midrange focus of EL34s, but they don't get harsh in the high-end, nor do they lose any bass. If anything, they get thicker as you crank them up. They were extremely dynamic and linear...I was able to control them easily with my playing dynamics. Extremely musical...and have a certain "Hi-Fi" overdriven sound in that they are so rich yet balanced.
Cranked, the KT77s DELIVERED. Talk about a huge, yet singing tone. I guess the words "Marshall-esque" or "British-sounding" apply, but the KT77s give much more than the midrange crunch those phrases describe. They give bass CHUNK, and somehow give a sweet, angelic treble response in the process. It's as if my favorite characteristics of 6L6s, 6V6s, EL34s, and KT88s were all wrapped up into one tube, and then balanced with each other so they work in harmony.
I'm sorry this is SOOOOO long, but there's so much to praise on the new JJ KT77s. Someone could give me $5,000 to spend on any EL34 type ever created, and I wouldn't look past the JJ KT77 (although, in honesty it does have me curious about the original Genalex
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