And then the Tung-sol KT120 which has even more "pop" and because we run them so easy, the tube may outlive you. The custom built cross overs have volume controls on the mids and tweets, so dialing in the right amount mid's or high frequencies is a breeze. mA. The grey glass is a upgrade of black glass treasure series. 10/99. You could describe KT88s almost the same way as you did w/ the KT77s above, except with way more headroom like I said. These tubes have taken quite a journey since their introduction. The Gold Lion KT88 sounded MUCH better and a more balanced tube from top to bottom. 140. Power tubes like EL34's and KT88's are good for about 2500 hours or more. Declaration All items guaranteed 100% BRAND NEW in the original edition Box. 25. $41 99. com The KT77 was the British version of the American version of the British EL34. 95 each) Let me reiterate that I would be happy using either one of these three fine tubes and perhaps in a different circuit they might outperform some of the tubes above such as the Mullard and Tung-Sol. Dec 14, 2014 · So far the JJ KT77, the Winged C EL34 and the Tung-Sol KT120, in a PrimaLuna amp which came with branded KT88's. All that’s required is to flick a switch on the right-hand side to choose between the basic EL and KT families and the amp does the rest. So it can be used in most EL34 amplifiers. --. The quick answer to the difference between EL34 vs 6CA7 or EL34 vs KT77 is simple. Jan 03, 2017 · A real EL34 is a pentode tube, vs. Filament Current. Tube amps JJ ELECTRONIC KT88: This tube was first designed back in the early 90's by JJ to be a completely new take on the KT88 design with the ability to withstand peaks of more than 50 watts. 2, октобокс с сотами, стойка. Je sais qu'un V. “KT77 is a beam power pentode with octal base. kt77 has different tone and about the same output as el34 about 50watts a pair kt88/6550 is a different animal, look for a little over 80 watts a pair. UL and Triode mode are better than EL156 SE. AD200, SVT, Marshall 31 Mar 2020 kt77 tubes also are more dynamic in sound and suffer from less compression. Also, unlike 18 Apr 2017 Left to Right: EL34, KT77, 6550 and KT120 However, electrical characteristics do vary between tube part numbers, i. Marconi-Osram Valve Co. Message La KT77 est je crois une évolution de l'EL34 et pourrait manquer de "saveur". The last time I was here it seemed like KT77 14 Jul 2016 Anyone tried KT77 or 6CA7 in a British- or Bassman-inspired amp 4:88 which has KT-88 and that amp is rated a 250 watts for 4 vs 300 for 6 I am trying out the Genalex Gold Lion KT88 reissu. A number of UK suppliers claiming they are selling current production Winged C valves which are made in the St Petersburg factory in Russia. They can be noisy when 10. KT77 vs KT88. KT88 Sensibly equivalent ¶ to: 12E13 6550 7D11 CV5220 See also: Design for a 50 Watt Amplifier - KT77 & KT88 Advert - New Audio Output Valve The GEC KT88 - New KT88 Advert - KT88 Advert - KT66 and KT88 Advert Just Missed the Podium: JJ KT77 ($19. The 6CA7 is technically a different tube and has a bit more of an American tone as well as being much fatter. I especially prefer the clean sound. They KT88 Author: M-O Valve Subject: JA-FP-2000-10-01 Created Date: 10/1/2000 7:35:29 PM PSVANE KT88-TII HIFI Audio amplifier Vacuum tube Best matched 8 pcs 100% Brand New The price is for 8 pcs, we will send the Factory full matched tubes to you. The KT88 is a beam tetrode/kinkless tetrode (hence "KT") vacuum tube for audio amplification. It is also divided into two classic grade and premium grade same as treasure series tubes. 800. RCA’s first version of this tube was an early ‘octal’ base tube. The KT77s can give you a warmer sound. 43mm. 1. Two died in their boxes (the dreaded white getters) after being pulled from the amp (less than 350 hours of use). But may go longer in an amplifier with a conservative design. Qualified orders over $99 will ship to you without incurring a shipping fee. Nov 15, 2020 · KT77 vs. JJ 6L6GC. The JJ KT77 is not quite a tight as the E34L but tighter than an EL34. What sound characteristics do the KT88s have? The KT88 is known for its incredible clarity in the mid-range frequencies. , с доставкой по Москве или пересылкой 1- м Laney VC amps, Crate V and VC amps including the Palomino, Budda amps, The JJ KT77 is a drop in replacement for almost any EL34 type tube amp for a The JJ KT66's and the JJ KT88's are the same diameter as the original New 2x Genalex Gold Lion KT88 | Factory Matched Pair / Duet / Two Tubes Genalex Gold Lion Platinum Matched Pair KT-77 KT77 Two EL34 24 Hr Burn- If the KT77's are anything like the KT88's they will have a shitload of low end, and I wish I could get some kt77 vs 6l6gc reviews around here! Buy Psvane New Matched Pair KT88-TII Vacuum Tubes Mark II KT88 Power Tubes Factory Test&match(KT66 KT77 EL34): Tubes - Amazon. com over the years See full list on tnt-audio. Discussion in 'The Workbench' started by LPMarshall hack, Mar 30, His live tone was driven by his Marshall 1959's modded to run off KT88's. And about the tung sol 12ax7: get them. May 25, 2019 · I posted this reply on your YT video as well: I agree that the JJ sound more tight and clear. kt88's are just fucking huge =D. Gold Lion KT77 vs KT88. ANOS RFT EL34 Matched Pair I have two Prima Luna Prolouge four amps, both running Gold Lion KT88 tubes. KT88, che ne pensate della Kt77? Leggevo che, come sostituta della El34, pare che riesca a coniugare 14 Dec 2014 The KT77 are more KT88 likewise, than EL 34. 16 Jun 2019 Some people think the KT88s sound a bit bright. I shifted from Ruby 6L6 to Genalex KT77. 6L6GC, 6L6GB/5881 and KT66 Tubes Different Power Ratings. Everyone loves their sound. I was also surprised with the midrange of these tubes. Re: JJ KT77 vs E34L (not EL34) Discuss! « Reply #13 on: June 30, 2011, 04:21:42 PM » might be worth trying a 5751 in V1, just to reduce some gain hiss slightly while not actually decreasing the overall preamp gain THAT much. May 19, 2020 · The 6L6 sound kinda nasty, aggressive. great bass authority, and a smooth extension on the top end versus the Shuguang that The KT77 beat out the reissue el34 Mullard and the Primaluna el34 in my system. Why some people say don't use SS power amp with Seymour Duncan Guitar Pickups, Bass Pickups, Pedals KT77 triode mode connection. It is more of a hybrid tube between the KT88 and EL34. The JJ KT77 is a designed on the famous Marconi Osram Gold Lion KT77 The Original Marconi Osram KT77 valve had no Kink in the curve of the valves sine wave; hence the KT stands for kinkless tetrode. I have used the Siemens RFT EL34, SED Winged =C= EL34, Mullard reissue EL34, JJ EL34L, KT77 and KT88 plus the Tung-Sol KT150. Psvane black glass treasure series. So far I have tried JJ-Kt77's, TAD EL34B-STR Premium's (which are relabeled Shuguang tubes), and Sovtek 6L6WXT+'s. zimbloth, Dec 10, 2007 If you can justify the cost, the KT77 could be very satisfying. thetubestore. The Siemens were close but did not have the full spectrum sound that these have. You can use 6CA7 or KT77 in place of EL34. We supply the very finest that you can get and our testing is the best. Plate Current (max). The E34L is a special low grid voltage version and is not always interchangeable. Dec 29, 2007 · If your new ST-70 has an updated power transformer from Triode or Dynakitparts then KT88's are an option. A. Both of their power transformers are rated at 5 amps per channel instead of 3 amps like the original power transformers. 2 (screen) dissipation. KT88. Wondering if I have to stock these tubes for future use. Statistically, they are not quite as dependable as the Mullard EL34 reissue. If you use KT120's DO NOT ship the amp with the tubes installed. Posted by triiiangle (A) on October 19, 2008 at 09:20:38 Can anyone here comments on the sound of the Gold Lion KT77 and KT88s? I currently May 01, 2013 · The KT88's did have a deeper bass but for jazz guitar not sure that's really an issue. Genalex Gold Lion KT88. 42. One Amp runs the midrange horns on each speaker and the other powers the 18" bass drivers and horn tweeters. DC cathode current. Once you start to push a little air, however, your amplifier will show off what it can do and the […] The JJ KT77 is a drop in replacement for almost any EL34 type tube amp for a little different flavor. 0 - KT77 vs 6L6GC vs EL34 vs KT66 Power Tube Comparison El34 vs El84 vs 6V6 vs 6L6 vs 6550 vs KT88 (Reussenzehn). There is a lot of confusion in the market on Svetlana and Winged C Valves. Jan 05, 2010 · Power tubes can have a dramatic effect on your amplifier’s sound. 19 Sep 2019 This warning goes for all power beam tetrodes like the KT88 and the 6550, by the way! KT77. Shop our great selection of KT88, 6550, KT90, KT120, KT150, vacuum tubes now. Sort by. EL34, 6CA7 and KT77 are all drop-in replacement of each other. Mar 31, 2020 · Kt77 vs El34: Differences You Need To Know March 31, 2020 Gin Guitar and Amp 0 A common tube replacement question is whether the kt77 tubes is going to be an improvement over the el34 tubes. Posted by triiiangle (A) on October 19, 2008 at 09:20:38 . It can be used in most EL34 amplifiers. This doesn't mean a huge margin, but if you're wound really tight or your amp is hard on tubes, the Mullard might be a better choice. The Tung-Sol KT120 (and KT150) tubes are new designs, basically more powerful versions of KT88 and 6550 tubes. e. A faithful reproduction, this Genalex Gold Lion KT77 has heavy glass and ruggedized plates that will allow it to KT88 Gold Lion Platinum Matched Pair ( Single). Anode voltage, 250 V. 8W rms at triode mode. May 31, 2019 · The KT77 has been called the Ultimate EL34, and it features an internal design that is similar to the 6CA7, but optimized for use in audio applications. My amp has a bias switch. 51mm. EL34. KT88 tubes draw about double the natural plate current of 6L6s, so you get amazing headroom and punch. Jan 20, 2009 · But specifically, what are the tone differences between KT66 vs KT77 in a Marshall 50 watt MV style amp? I have a set of GTKT66-HP's in my Emplexador that I borrowed from a friend and I really like them. Svetlana. EL34 versus KT88 tubes. Test Amps: 1973 Marshall Super Lead model 1959: This amp is completely stock using NOS pre-amp tubes. You really have to think of this tube as its own entity. At the very least they draw more filament current than KT88s. 95 each); Svetlana EL34 ($23. OUTPUT PENDODE EL34 is an octal power tube with a maximum plate power of 25W. Many affordable options are available on eBay. Screen Voltage (max). I think they cover pretty much the same range of sounds, but the difference I hear in my amp is that the kt77´s sound more relaxed and the kt88´s have more punch. Quote Any thoughts on the sound difference between the KT77 and KT88? I have VRDs and am considering going to the KT77. 's (Genalex) legendary Gold Lion KT88 was the heart and soul of classic tube amplifiers like the Dynaco Mark III, McIntosh MC275, and Marshall Major. PS: KT88s are 50w tubes (6L6 = ~35w IIRC). com offered a set of five EL34-type tubes for review (JJ KT77; JJ EL34 II; Svetlana EL34; Genalex Gold Lion KT77 and Mullard EL34) I jumped at the opportunity. 6550 / kt88 / kt90 KT88's generate a lot power, handling significantly more plate voltage than other power tubes. One of the nicest sounding tubes for the ST-70 are the JJ KT77's. 3 mar 2019 Anzi, tornando alla questione El34 vs. If you have a Marshall amp and find EL34’s too compressed and 6550’s too crunchy the JJ KT77 may be just the ticket. EL34 versus 6550. From time to time The EL34, the CLASSIC British tone, loved by many. It's best to try both and 21 Aug 2019 kt66 is substitute for 6L6 i think. It is divided into two classic grade and premium grade same as treasure series tubes. I like 300B/2A3 SE but we can get 6550/KT88 are easly to get one of poket maney than 300B. At low volumes, the difference between one tube and another can be difficult to distinguish; for many listeners, it’s almost not worth talking about. $20 99. The KT88's did have loads of clean headroom and did not seem to color the sound as much as a 6L6. Hate it when $60 a pop tubes die prematurely! So yes, I am a little biased against the Gold Lion brand. The 6CA7 is the US designation for the EL34 and is complete interchangeable. 2. We carry all of the major brands in NOS, vintage and New Production vacuum tubes. L KT77 it is unpublished as the New Sensor datasheet is a copy straight out EL34 vs 6L6 vs KT88 guitar amp output tu The JJ E34L is more robust version of KT88 vs 6550 tubes – are they interchangeable, different, or, indeed, what are they? Even people who have played tube amps their entire lives might not have 22 May 2020 KT77 tubes blend the tonal qualities of British and American tones; Fantastic option for upgrading vintage amplifiers. leden 2008 EL34 vs E34L vs KT66 vs KT77 vs KT88 Někdo mi říká že se to dá normálně vyměnit, že smaj stejný pracovní podmínky a hodnoty, někdo že 30 May 2020 Post subject: Tubes KT120 vs KT88 you might want to look at a good 6CA7 tube, a good KT77 (Gold Lion is a great one), the TungSol 7581A, Sujet du message: KT77 vs KT88. Anode current, 140 Bias voltage, -15 V. It has more power, fatter bass and more headroom than the EL34 and E34L while providing very detailed tones. It has an international octal base (indicated by the '3' in the part number) and is found mainly in the final output stages of audio amplification circuits; it was also designed to be suitable as a series regulator by virtue of its high permissible voltage between heater and cathode and other parameters. The EL34L is an EL34 with a bit more power, the KT77 is a beam power tetrode instead of a pe EL34 Review Chart (View our complete selection of EL34 / 6CA7 / KT77 vacuum tubes). KT77 ultralinear mode connection. OUTPUT PENTODE 6CA7 is a beam power pentode with octal base. Some, but not all, were versions of existing American beam tetrode tubes or European power pentodes, such as the KT66 (6L6 similar), KT77 (EL34 and 6CA7 similar), KT88 (6550), and KT63 (6F6, pentode but almost identical characteristics). Anyone ever compared KT77 and 6550 to KT88 and 6L6? Recently i am very curious about these Feb 18, 2012 · KT77 sound good but the response is centered in highs. In guitar amplifiers when substituting these for EL34 it will give greater clean headroom and less compression. KT77 penthode mode connection. Another interesting thing we noticed was the SQ with the KT88's improved once I fitted the Analysis Plus Black Mesh Oval 9 speaker cables I also bought with the amp. Here’s what JJ say about their KT77 Valve. Compared to JJ 12ax7 it´s like taking a blanket of your cab. they will add nice high end sparkle. $48 99. Our tubes are always tested, matched and guaranteed. Can anyone here comments on the sound of the Gold Lion KT77 and KT88s? I am currently running a rather nice KT77 PP UL amp. Here is what I can tell you about it. I am going to buy a set but I am thinking maybe I want to try the KT77's. 6L6GC / 7027 A 7027A EL509S 6550. The Gold Lion KT77 is a drop in replacement for an EL34 or 6CA7. JJ Electronic - Vacuum tubes, Capacitors, Amplifiers. A modern re-creation of the Well here you go,, my two cents. Dec 10, 2014 · Gold Lion KT77 – This tube was a treat to listen to. The 77's have even a bit more low end extension than the E34L's and they have a nice sizzle in the top end that is not brittle. The following guidelines should be taken into account: The free shipping option allows TubeDepot to choose the most appropriate carrier and service. These are all just generalities. 425. V. Since its production ceased in the early 1980s, the Genalex Gold Lion KT88 has become expensive and hard to find. For a while, the EL34 and the 6CA7 became the single EL34/6CA7, while production of the KT77 ceased in the 1980s. eth2 2179 eth2 2179 Forum Ultra Veteran; Regulars Having a quad of GL kt77´s and GL kt88´s myself, I can comment about their differences. Also Nov 08, 2019 · for power tubes i tried kt88, el34, 6ca7,6l6gc, kt77 personnaly, I like 6l6gc best for my utopias, and el34 best for my planar hifiman arya in general i find kt88 to be hifi , almost solid state like with great bass and details,lacks a bit in refinement, and el34 more romantic and refined with emphasize on mids and rounder sound, good soundstage. The tube life issue may have to do with the tube socket grid bias resistance value with regard to the 250k limit of the JJ KT77 reported by JJ Electronics, at least partially due to the absence of the pin 1 connection they chose for compatibility with Fender Twin amps. They sound very full and detailed with nice bass clarity which fills the room. com ✓ FREE V. View: List; Grid. Grid no. New & NOS power tubes from Mullard, Tung-Sol, Telefunken, Sino, GE, Telefunken & more! My reference power amplifier is the Bella EXtreme 3205, a push-pull pentode that can accept either a quad of EL34/6CA7/KT77 tubes biased at 40mV or a quad of 6550/KT88/KT90s biased at 50mV. Нюансы при использовании на студии. How about other tube options (sound signature)? 3. And about the Gold Lion KT77, which is the only kt77 i know, i would never replace a =C= El34 with it, for instance. Since many of us have never actually listened to a KT77 from the original producer, I can not say that they nailed the reproduction. I think better than 300B for cost(C/P). kt77. The inexpensive Van der Hull MC Hybrid cables made the amp with the KT88's sound very boomy and extremely flat, the Oval 9's lost the boomisness Tung-Sol EL-34B vs Genalex Gold Lion KT77 for Cayin A100T Integrated Tube Amplifier Hello, I recently got a new set of Speakers and an Integrated Tube Amplifier. com ~$73 CDN each. Not a very good description, I know. By eth2, April 19, 2017 in Talkin' Tubes. The 6550 itself is a more powerful valve then the EL34 (35W instead of 25W) and is usually good if you want a slightly louder and rather cleaner (slower to distort) sound from your power amp section. TubeDepot carries a selection of 6550 / KT88 / KT90 Power Vacuum Tubes. aside from the tonal differences between tube models (and individual tubes, really), you get more clean headroom when using kt88/6550's. Reply to this topic; Start new topic; Recommended Posts. All of those types sound different from one another as well because they're all designed differently. Period. Those were the results in my amp, in your amp YMMV. The Gold Lion KT77s are top Обзор и сравнение студийных наушников AKG K271 studio и Beyerdynamic DT770 Pro. The EL34 is a thermionic valve or vacuum tube of the power pentode type, first made in 1949. Предлагаем купить лампа JJ KT88 подобранные в пару/четверку для усилителя мощности за 4 200 руб. To me the 6AC7 give a beefier sound the KT77 is a bit more 3 Feb 2011 Are you sure you guys aren't thinking of the KT77? The KT88 is designed to be a drop-in for an amp running 6550's, e. Oh and the Gold Lion KT77 is a very nice tube and I think you would love it. Hi! Well the KT88 is pretty much an upgraded 6550. The JJ-KT77's and the Sovtek 6L6WXT+'s seem to have a hole missing in the strength of stringed instruments such as violin, fiddle, steel guitar, banjo and such. In KT88's the most common is the Electro Harmonix which is great, the Mullard re-issue and Gold Lion re-issue which in essence are the same tube and are superb. I am looking for something between a 6L6 and an EL34. We agreed that I’d throw a few of my own tubes, including the Tung-Sol EL34B and Shuguang 6CA7-Zs I purchased from thetubestore. Mullard EL34. Using EL34s, the 3205 will produce 50 watts per channel; use of KT88s will give up to 60 watts per channel. While all 6L6 types are pin compatible with one another, some amps are designed only for the higher powered 6L6GC. ONE-YEAR WARRANTY !!! 1, PSVANE T-Collection series MK II use the Carbon Microcrystalline technology. $22 99. I have not tried any of the KT88 you mentioned however, have heard the TS 6550 is a nice tube. So if your curious try some out and see for yourself in your amp. Excellent quality. Советы и общие 15Hzvs18Hz; 4000Hz higher high-frequency ? 24000Hzvs20000Hz; Has passive noise reduction ? Has a detachable cable ? Has a neodymium magnet ?. JJ EL84 / 6BQ5. Sound comparison of JJ EL34, EL34L and KT77 in a marshall jmp50W. The only caveats are to ensure that your power transformer can supply an extra 500ma of heater current per tube and that the range of bias voltage adjustment is correct. 5. 7 Feb 2009 I was away for a bit and as I looked over the forum here I noticed Peter talking about KT88 tubes. Genalex Gold Lion KT77. W. These tubes are the best I have tried in my PrimaLuna Prologue Premium integrated amp. ELECTRON DEVICES. The KT77 is an interesting tube and is a drop-in substitute for the EL34. As a result, KT88's and 6550's are produce cleaner tones and have low distortion, making it popular amongst bass amplifiers and high end audio applications. on their own, i don´t like the KT88 but both tubes combined is awesome. Plate Dissipation (max). F. Plate dissipation. KT66 KT77 KT88 300 B КОМПЛЕКТ постоянного света: Godox SL60W v. However, el34 tubes are more durable and slightly less expensive. g. tubes are new designs, basically more powerful versions of KT88 and 6550 tubes Design for a 50 Watt Amplifier - KT77 & KT88 Advert - New Audio Output Valve The GEC KT88 - New The KT88 is one of the few classic audio output valves. The sound of the KT77 is usually described as 12 Aug 2020 These amplifiers are auto-biasing and can use KT88, KT77, KT66, 6L6 and 6550 tubes, making it easy to compare the differences. A good 6L6 tube has plenty of bottom. Superb service from tonal valves. The TAD's sound the best. The reason being I'm once again stuck 27 Sep 2016 Роман Вминялкин продолжает настраивать усилители и сравнивать звучание разных ламп. But I Like Sound of KT88/6550 Single Ended Amplifier. Tung-Sol KT120 (new production) on loan from Thetubestore. I am new to power amps. To my ears nothing comes close to the treasures!!! In terms of failures the only one was a JJ KT77 which failed after a month of use (Red plated). 300B is very diffcult to get 10W rms. **Before anything else, I must say I do not recommend anyone to change their own power tubes without having a qualified technician adjust the bias. el34 / kt77 / 6ca7 Popular in high powered audio and high end guitar amplifiers, characterized by greater distortion at a lower power compared to other power tubes. 8. KT77 works fine in place of EL34. 95 each); JJ EL34 II ($19. a 6CA7, or a KT77 or KT88 which are beam tetrodes, the 6CA7 being the American-made substitute or the EL34 which was a Philips-Mullard creation I think, so the American manufacturers couldn't use the particular pentode construction so they made a tetrode that could substitute directly and tubes of either type You see a huge difference in power stage. To me, Genalex Gold Lion KT66 is the best current production power tube, it sounds elegant and fat, it is a pleasure. KT88 is a beam power tetreode, its anode limited dissipation power is 42W. May 01, 2017 · Dan, the amp was only months old and it came with the factory fitted Tung Sol KT88's. Can anyone explain the difference in sound signature between 300B 2A3 KT88 EL34 tubes? I linsten to 50% rock, 25% pop, 25% classic or whatever sound good. Fig 2. $19 99. A number of different KT tubes were later marketed by M-OV. . Mullard EL84. So, to unravel this, first let’s look at the various types of 6L6 valve. Don’t let the low prices of these tubes bias Chinese Psvane KT88-T MKII Premium Grade. Plate Voltage (max). Thanks -Frank Dec 16, 2014 · I have not tried the GL KT77, but was not impressed with the sound or the longevity of the quad of GL KT88 I got from thetubestore. Sent from my has anyone ever used a Kt77s in place of there EL34s? They're supposed to sound a lot better. $13 99. Если у вас когда-нибудь возникал вопрос 11 Sep 2020 Tube Shootout 2. Sovtek 5881 KT88 Quad vacuum tubes are highly sought-after tubes with an amazing sound profile that will please even the pickiest of audiophiles. Chinese Psvane KT88-T Premium Grade. Gold Lion KT77 Notice: These are great tubes. Small signal tubes with numbers like 12AX7, 12AU7, and 6922, and rectifier tubes like 5AR4 may go 10,000 hours. So you get years and years of enjoyment. The KT77 avoids this. 5881 vs 6L6GC Valve/Tube. Jan 01, 2016 · When Jon Esau of www. Another slightly smoother EL34 tube choice than typical electric guitar tubes is KT77 by JJ. any experience of alternatives to KT77s such as the new JJs, or even KT88 or EL34s? JJ Electronic (Tesla) EL84, EL34, 6L6, 6V6, 5881, 6550, KT77, KT88 6CA7 6V6S 5881. 230. UL KT88 can get 12W rms. The same can be said for the KT66 in comparison to the 6L6GC/5881 and the KT88 in comparison to the 6550. Items 1 - 8 of 8 KT66 / KT77 / KT88 There are 8 products. These tubes are as musical as a real Genalex with the ability to create the fullest and most exacting image of any tube in its class. ” Here is what one user says: “Tone-wise the KT77 is somewhere between an EL34 and a 6L6… The same process is true for EL34’s , KT66, KT77, KT88, but the numbers will be different according to the maximum power the valve can handle Most manufacturers state the maximum power the valve can dissipate is 30 watts. Thanks to an advanced auto biasing system, they can work with 6L6G, 6L6GC, 7581A, 6550, KT66, KT77, EL37, EL34, KT88, KT90, KT120 and even the very powerful and currently very popular KT150. There are several in the sequence as manufacturers gradually improved it over the years and discovered new ways to push the tube to higher powers.