Is this what they mean by "Double Blind" testing?
An enjoyable read in any case.
I'm still trying to decode the results. I actually prefer a good English Gin for these critical sessions.
Best...
KR Audio KT88 Vacuum Tubes
Does anyone have experience with these power tubes? I understand they are well made and likely last longer than their Russia or Chinese counterparts. But, they are much more expensive. My real question has to do with the KR Tubes sound quality. Would you replace good sounding Gold Lion KT88s with the KR Audio tubes for a sound quality benefit? I've also read they make the similarly expensive EAT brand tubes that some prefer.
17 responses Add your response
I have a drawer full of tubes, a Dennis Had Firebottle HO power amp and an original Freya preamp...both amps use 6SN7GTB tubes (the Had uses one, the Freya four). Recently I was trying various KTs (and 7581As from Tung Sol) power tubes from the stash in the Had amp (the 6SN7s are all NOS GEs which I prefer over anything else I’ve tried) and was enjoying how interesting and different all of ’em sounded. I was smoking pot so EXCUUUSE ME! After reading something from a guy who made a passionate case for KT120s over 88s (GLs are my faves of those) I put a pair from the collection in the amp and man...he may have been right. The 120s are now preferred...until I put the GL 66s or 77s back in for some reason. Or just hook up my Pass XA-25 again...that’s my other power amp that rests until called upon. I gotta quit smoking that stuff, or smoke more of it. Something, anything. |
I Have the KR's powering my PL HP, 8 tubes in all. I did pay less then $1000.00 a few years ago. 16 total. There's always pos. & neg. opinions on price, performance,etc. Me, I swear by them. Tried many well known tubes before I went to the KR family. These tubes are phenomenal! I'm running a Don Sachs pre-amp feeding to my Klipsch base horns, & Altecs 311's with Facial pro tweeters. If anyone wonders what fast base should sound like, my setup can show you. +1 for the KR's |
Hey trivema, Thanks for your description of the KR KT88 SQ. Looking for a lusher, fuller midrange if anything. In pursuit of that actually got rid of Nordost Valhalla speaker cables for Wireworld Platinum. Needed Nordost's Odin top cable but the numbers are nuts. Speakers are Wilson Yvette, have Sasha Vs on order. If not over emphasized, a tighter top end and bass are great. Yes those used original English KT88s are the real McCoy, I'm told. Would need to buy eight to get four good tubes... and then when one goes. Not a rabbit hole I want to start through. Thanks though. |
I agree. I don’t think Moon Audio would fib about that. Eunice told them that or it was some confusion based on conversation over other tubes and the Abyss collaboration. I like the Sophia’s a lot. They are sort of a Goldilocks tube being a touch brighter than the Gold Lions but not as bright as the KRs. I like them as an alternative to the KT120s plus I love the Blue Glass. |
@coppy777 you've got some serious CJ gear! I think you'd really like the KR KT-88. Per verdantaudio the sound signature of the KT-88 sounds (pardon the pun) similar to the 300B XLS, very tight, controlled yet full bass, with clear, crisp, articulate treble. The mid-range of the 300B XLS is very lush, but not mushy, i.e., it's no so warm it muffles everything. More like sublime ++. I wouldn't call the 300B "bright," but as verdantaudio notes, depending on your speakers, the KR's could brighten up a brighter speaker. My Cary with the KR 300B XLS is driving a pair of Focal 716S and Vienna Acoustics Haydn's with a vintage Klipsch sub. Not my #1 setup, but the amp and KR tubes sound wonderful even with the modest speaker set up. I did run the Cary for a bit with my #1 speaker grouping, Klipsch Forte IIIs and Focal Aria 926 before I moved the Cary to system #2. and didn't consider it too bright. My guess is you have some fantastic speakers given the level of CJ tube gear you've got. I think the KR's would definitely be an upgrade in your system. If you go there, I found the 300B XLS needed about 100 hours to break-in and really begin to show their stuff. Cheers, enjoy the music!
|
VerdantAudio... just looked at your site. Very impressive offering. And thank you for the perfect answer. Which begs the question... Other than blue, how is the SQ of the Sophia Electric KT88s vs the Gold Lion. Moon Audio folks are nice folks and honest. If made in the USA is on their site it’s an honest error on their part. Czechoslovakia is correct for KR. Still higher cost for manufacturing than Russia and they are likely a much smaller company. |
@verdantaudio , as a dealer, perhaps you can answer a question on where they’re manufactured? This Moon Audio listing claims made in the USA which could help some justify their higher price. However, I thought KR was based in Czechoslovakia and their tubes manufactured in Russia. “Made in the USA, these tubes stand out for their superior performance and reliability, making them a valuable addition to any high-fidelity audio system.” |
I am one of the dealers for KR and have had them in my own Art Audio Opus 4s. They have the same power output as a typical KT88 but the plate dissipation of a KT120. They will last longer. This is the same recipe KR used on their 300Bs. Plate dissipation is 50w vs. standard Western Electric Spec of 40w. In practice, they are more linear. "Better" top end and tighter bottom end. This means tighter bass response but also means a brighter presentation which is why better is in quotes. In my system I found them to be too bright and shifted to a different tube compliment. My amps also accept KT120s and I opted for those to get just the right tonal balance I was looking for. If you are looking for more top end energy and tighter bass, they are incredible. If you are happy with the Gold Lions tonal profile, move on. |
My amplifier is a Conrad Johnson ART27a class A producing 36wpc. For the benefit of the first three respondents who have not heard the KR tubes, the amplifier lists for $22K. The pre-amp is C-J's ART88 at $28K. All pretty high end sound producers. My interconnects cost several times what a set of the KR's would run and the speaker cables sell of about what the amplifier does. So I'm willing to spend $1300 for a set of four if they truly sound better than the Gold Lions. I just re-tubed the amp's KT88s after about two years of use for about $400. I buy tubes from reputable sellers or C-J, never on Amazon or eBay where the lower quality tubes end up. I'm told New Sensor separates out their best testing tubes and they become the Gold Lions. As for the Sophia Electrics, I understand they don't manufacture their own tubes either, they come from Shantung in China. But they are again some of the better testing valves from that company. Rather the Gold Lions of Shantung and pretty also. Thanks to trivema and retiredfarmer, thanks for your input; very helpful. Tubes are a maintenance issue, especially in a circuit like this one which drives them hard to produce that much class A sound. At worst case the KR Audio tubes will likely last longer and the current Gold Lions will become backup for the next replacement cycle. Still, don't need power tubes right now... unless they really sound better. |
I think it depends on “how good” your amp is, as well as the rest of your system whether you’d experience any sonic benefit. If you’ve got a super high end single ended with no negative feedback, like Japanese Audio Note, French Jadis, VAT or PP McIntosh and the rest of your system is equal, I think you’d like the KR Audio tubes. If a “lesser” amp, like Line Magnetic, or Willsenton, not so much. The last two are not bad amps, but run negative feedback to reduce distortion and mutes some of the second order harmonics which makes tube rolling less impactful. I don’t know about the KT 88, but I have a Cary Audio 300SEI LX-20 that is designed for the KR 300B XLS which puts 550 volts on the plate with 55w dissipation and 20w output. The Cary will eat normal 300b’s like a six year old eats through Frosted Flakes! The KR XLS in the Cary are fantastic, Deep, tight impactful bass, something normally missing from 300b. The midrange is simply heaven on male and female vocals, acoustic guitar and strings. The treble is clear, clean and very articulate. I also have a Dennis Had Inspire KT-88 that came with Gold Lion as stock. It will also run 6L6, EL34, and 6550. The Gold Lion KT-88 is the most balanced, linear and musical tube I’ve heard in the Inspire. It’s a simple SEP design with one 6SN7 or 6SL7 as the signal splitter and driver in front of the output tubes, no negative feedback, and hand built point to point wiring. It was only $2,000. Would I roll in KR KT-88s at $900/pair? Maybe, if I won the lottery! Bottom line, I’ve had good experiences with the Gold Lion series of power tubes, definitely a fan. Do I think the KR tubes are an upgrade worth the cost? Absolutely! If your pocketbook and system can handle them.
|
@bojack ,it is a sadddd fact that in this day & age,many people have more $ than brains! |
$600.00+ for a matched pair of KT88 tubes,hahahahahahahahahahahahaaaaa... |