6l6gc tubes equivalent I’d be careful putting 5881 in an amp designed for 6L6GC as you are The 5881 is a military spec approximate equivalent to a 6L6GC. GU-74B (original TubeDepot carries a selection of 6L6 / 5881 / KT66 / 7027 Power Vacuum Tubes. The 6L6 tube equivalent part numbers 5881 and 7581A vacuum tubes are acceptable substitutes in some amplifiers. The 7868 is a 9-pin pentode, 19W, 6. The 5881 is a 6L6 rated for 23W. Consider these 6L6 tubes as an excellent choice for any type of music, delivering crystal cleans and smooth breakup with plenty of punch. It has a 35W plate and matches closely with a 6L6GC. 7581A refers to an unaviable 6P3S is listed as equivalent or similar to 6L6GC and others so Iam 6П3С, Tube 6П3С; Rohre 6П3С ID3565, Beam Power Tube The 6Π3C (6p3s) is "equivalent" to a 6L6GA. Many Russian 6L6 equivalents (19W) were relabeled 6L6GC, and of course they wouldn't last at higher voltages and dissipation levels. These Tube 6L6GA or Röhre 6L6GA ID3922, Beam Power Tube, Octal (Int. The American vs British thing is still kind of ongoing. The 5881 is a 6L6-type tube, with essentially the same ratings and electrical characteristics as the 6L6GB, so any difference in sound would be due to the normal variations that might also exist 6L6 and KT66 are essentially the same tube, but depending on the 6L6GC and KT66 being compared, the 6L6GC might be smoother, while the KT66 might be a tad more aggressive. 2 ~ 1. VACUUM capacitor relay long life non less 5000 hours. whoaru99 Epic Member. Subscriber The big question is how much plate voltage your amp runs and how much plate voltage the tube in question can handle. These tubes, vital components in tube amplifiers, significantly shape the sound of your guitar amp. Wonderful, sweet throated British tubes from the legendary Marconi-Osram Valve Co. There has been many 6L6 variations, but the most common ones today are: 6L6GC - 30W version. Reactions: Bill Ferris, tubelectron, drtool and 3 others. Not withstanding screen resistor values for the different tube types, it should be noted that putting el34 / 6ca7 / Kt77 tubes in an amp designed for 6l6's is usually a bad idea due to the heater current draw of the el34 variants. The 6P3S-E is the military version of the 6P3S with a coin / wafer base. Vacuum tubes. KT88 and 6550 are optimal at a much lower plate impedance than the 6L6 (3-4K as opposed to 5-8K for a 6L6). They can produce same amount of power as the EL34 type. The use of treated grids and anode also improves the tube's overload capabilities for longer life. Start new topic; Recommended Posts. Rated 5. 6P3S-E / 5881 / 6L6GC output beam tetrode tube. Quick view-10%. This tube is now made in Slovakia and is a favourite amongst guitarists. The 6P3S (6N3C) is an equivalent of the famous 6L6GC tube and will replace them directly. Jun 19, 2011 #10 +1 on the russian tubes . 6L6 is the designator for a beam power tube introduced by Radio Corporation of America in April 1936 and marketed for application as a power amplifier for audio frequencies. It had a metal envelope which was popular at that time for use in radio sets since it was less likely to break than a glass envelope. I don't know which russian tube it is but there is suppose to be the 6L6GC equivalent you can get from the bay that are quoted to be good an cheap. BEAM PENTODE 6L6GC is a beam power pentode with an octal base and power of 30W for use in 6L6 amplifiers. pcs. Reflector $ 17. The 7581 has a plate voltage rating of 500 V--35 watts (5 watts more than the 6L6GC) and a screen rating of 450V--5 watts. I was starting to wonder if it might have been the 50+ year old coupling and/or bypass caps. Russian Military grade. 5881 - JJ Electronic. I was worried when those disappeared from the market (due to . I'm not sure why manufactures today didn't pursue making the KT66 amps these days. IF Allen says they're ok, I guess I'd give 'em a try. Regarding the contentious subject of the 'sound' of tubes, I will not touch on this thorny belief. This 6P3S tube was manufactured in 1957 at the Foton factory. The 7027A tube has similar power ratings but with a different pin-out. Preamplifying tubes; Power tubes ; Rectifying tubes; Capacitors. 6l6 tubes draw . Octal, IO) K8A, USA 1935 and shown. Equivalent to the 6L6GT, 5881. (The SND ones are 6L6GC type tubes in that bottle, there special versions) whoaru99 Epic Member. Evatco has the largest range of in stock tubes in Australia. It seems much easier to find an ideal equivalent from sovtek, mullard et al, and buy a set of four new ones. The 6L6 family of tubes (like the KT66) is actually a Beam power Tetrode. I'm planning on using this as a guitar amp. Obviously with out totally redesigning these great amps. Members; The Hiryuu. The 6L6GC may be used in all 6L6 applications, but where a 6L6GC is specified, then it must be replaced with a 6L6GC equivalent tube. Even then he noticed a big difference for the better compared to the old tubes. The JJ 5581 beam power tetrode tube is a high quality option for guitar and home a udio tube amplifiers. The Hiryuu. 's Genalex production line, with the Hammersmith factory marks. [1] [2] The 6L6 is a beam tetrode that utilizes formation of a low potential space charge region between the anode and screen grid to return anode secondary emission electrons to the anode and offers Both of those tube types require at least 1/2 an amp each more heater current, so Power tranny specs become important. I swapped between these and quality TAD 6L6 GWC STR red base tubes. I prefer them to KT88 in my amp. 6L6 tube types can vary greatly in size, so All JJ 6L6GC tubes are known to give off a warm and rich tone typified by balanced bass, harmonious midrange, and resplendent highs. The original Williamson amp actually called for an 807. The 6CA7/KT77 internals are closer to 6L6 or 6550 than EL34. To aid in cooling at the higher dissipation levels often associated with higher B+ voltages, the bulb length was extended for the 7027 The Sound is nice - authentic vintage tone. Posted June 25, 2007. Do you have a photo 6L6GC JJ Matched Power Tubes All tubes are matched and tested. Next Last. One of the most purchased tubes on the market for a reason, a warm rich tube that has nice lows, excellent mids and a just the right amount of chime in the highs. Revisions to the original metal 6L6 such as increased power handling and glass envelopes yielded new designations I have a new amp in house that uses 6L6GC tubes (amongst others) and the Winged C 6L6GC tubes it came with are starting to go. However, the 6L6GC, and others may not be replaced by the 6L6G, due to the lower ratings on this tube. Consequently, the sound of 6CA7/KT77 takes on characteristics from the 6L6 and 6550 tubes. How to convert a 6V6 tube amp to use 6ca7 or EL34 or 6L6 tubes. Russian military circa 1980's--very tough tubes that can take 500v on the plates. 6CA7/KT77 does not have the same smooth textures and breakups as the EL34. THD+N Portus. The KT66 tube is more linear and has less 6L6GC: Misc Used USA Branded Tubes Used Tested Good: $35 : Type KT-66/7581 Tubes The 7581/A tube is an industrial strength version of the 6L6GC which is also said to be the American equivalent to the British KT-66. Check with your amp manufacturer. Internally, the KT66 tube is an improved and redesigned 6L6 tube. 24 posts 1; 2; Next; noddyhead Posts: 2 Joined: Fri Oct 25, 2019 1:06 pm. NOS. VOSKHOD. Some often refer to it as an ice pick-like tone. The bass is beautifully full and organic and controlled and the overall 807 vs 6L6GC One of the main improvements of the 6L6GC over the earlier 6L6's (6L6, 6L6G, 6L6GA, 6L6GB) as well as the 807 and 6BG6G/GA (which are essentially 6L6's with plate caps and higher plate voltage ratings) is that the 6L6GC uses a special 5-layer plate material that has copper in the core, so that the heat is spread out. The first batch of measurements were taken of the left output tube of the left channel with the old tubes. The 7581/A tube is an industrial strength version of the 6L6GC which is also said to be the American equivalent to the British KT-66. Store "Soviet Tubes" on vacation, shipping available from 10 jule 2022. They were new/unused since the 50's and came with my amps. The Measured Voltage Gain Test Setup Each tube in this comparison was installed in the same custom built, fixed bias single-ended guitar amplifier in order to obtain the voltage gain measurements and conduct The new Tung-Sol 7581A vacuum tube is the answer. It is a great substitute for the 6L6 tube. 6 A. The 6pi3c is also commonly marketed as the "Sovtek 5881", which with a safe dissipation above 30W, isn't a true 5881. Then you get into the weeds with Russian equivalent power tubes. I initially wanted to get a quad of some GE 6L6GC's but those are impossible to find in Long-life. When comparing the 6L6 vs KT66 vacuum tubes, you’re diving into the heart of guitar amplifier tone. 00 The 5881 tube is the electrical equivalent of the 6L6 and 6L6G tubes, except that the dissipation plate and screen values are increased by about 20%. If the amplifier is spec'ed for 6L6GC, you cannot use a 5881 because the 6L6GC has higher plate, screen, and power dissipation ratings than the 5881. Go. In terms of sound, the TAD 6L6GCM-STR REDBASE produces the powerful but always defined bass EL34 tubes sound darker and heavier whereas 6L6 tubes sound brighter and fuller. I just want to preserve the Mullards. It means that the design of a 5881 tube will allow it to handle and resist vibrations and shocks better than 6L6 tubes. Without a thorough knowledge of tube types and their substitution possibilities, you may be over-paying for your new or NOS tubes you employ, or just pick the wrong ones. Add quantity: Available quantity: more. Near equivalent: 6L6, 6L6GT, 6L6GC and 5881. Also, not all 6L6 tubes are equal. There was a single bias trim pot for all four tubes. These are labeled as an STR tube. Can be used anywhere. Even if the bias and voltages could be sorted out, the 6L6 will suffer in the distortion and in the power output departments, under the load in the MC75. 7581A Tung-Sol (upgrades 6L6GC) King of clean-headroom tone! max. They have pretty much taken over where we used to use the 6L6GC-MSTR tubes. More Information. STR standing for Special Tube Request. I received them about 2 weeks ago, and have over 100 hours on them now. Subscriber. The KT66 tube has a shorter and fatter plate assembly and has a larger cathode than 6L6 tube. The valve museum site gives 6L6 and EL37 as "sensibly equivalent" to the KT66 despite Gm for the EL37 being more than double that of the 6L6 and nearly double the KT66. Quick view. It had a metal envelope which was popular at that time for use in radio sets since it was less likely to break than a The MESA 6L6 STR 440 is a premium grade, US equivalent with rich, defined bass, tailored mids and a shimmering top-end to keep every note amazingly intelligible, with a smooth, creamy character. Cart. Radio tubes are valves. I know these tubes are very costly and I would like to swap them with new quality replacements. 0 items 0,00 Near equivalent to tubes: 6L6, 6L6GT, 6L6GC and 5881. Revisions to the original metal 6L6 such as increased power handling and glass envelopes yielded new designations 6L6GC Power Tube Matching. The 6N3C / 6P3S Tube or 6pi3C is the Russian equivalent of the 6L6GT. 5 watts screen power dissipation and 24 watts combined plate and screen The conversion to 6L6 / EL34 is unlikely to give a significant power boost and it may even be detrimental and increase the distortion, but it will change the sound signature and this may be the desired outcome for a guitar amplifier. T. I decided it was worth the, relatively small cost as a test. RCA introduced the 6L6 to the world in the 1930s. 9A). For more information write to us Soviet Tubes. These tubes are compatible with most 6L6 variants except 6L6GC or 5881. What I have instead is a bunch of supposed RCA 6L6GC tubes designated as made in "Germany". Oct 31, 2019 #6 The 1614 are factory selected 6L6 for higher stressed service. . The 6L6GC-STR is with out a doubt one of the best versions of the 6L6 tube range. Tremendous harmonic content and an overall depth in sound make these Winged “C” / SED 6L6GC tubes another excellent choice for the purist. General discussion area for tube amps. Moderators: pompeiisneaks, Colossal. Jun 19, 2011 #11 Hiya, A Comparison of Current Production 6L6GC Tubes. My old ears probably The TAD 6L6GCM-STR REDBASE is the latest 6L6GC designed and built to claim to be the best 6L6 type tube ever manufactured. This is a strong claim, but TAD is sure that they have achieved exactly that. The 7581-A power tube has a plate dissipation rating of 35W, as opposed to the 6L6GC and 7581 rating of 30W. They are also similar to the 5881 and could be used as such. The big question is how much plate voltage your amp runs and how much plate voltage the tube in question can handle. The 6L6 was rated for 3. Technical specifications: Filament voltage: 6. La conception de ce tube offre aussi une meilleure résistance aux chocs et I do remember discussions about that very specific tube being a GC equivalent but most were only G equivalent Either way if you only needed the 19w version and could get a 6bg6 for 5 bucks it wasn't a bad deal. NOT 6L6GC! Won't support more than 250V plate. While the original tubes were getting to be on the weak side, they still played and sounded good. US equivalent with rich, defined bass, tailored mids and a shimmering top-end to keep every note amazingly intelligible, with a smooth, creamy My Knight mono-blocks have the original Mullard tubes including the EL37's. plate dissipation: 35W made in Russia I don't consider this tube as a 7581A but as a 6L6GC since it dissipates a Pmax of 30W. One of the best know is the old Sylvania 6L6 Review – JJ 6L6GC Tube October 5, 2015; Review – Tung-Sol 6L6G Tube September 29, 2015; Review – Tung-Sol 6L6GC-STR Tube September 29, 2015; Review – Svetlana 6L6GC Tube September 29, 2015; Review – Winged “C” / SED 6L6GC Tube September 29, 2015; Review – Mullard 6L6GC Tube September 25, 2015; Review – Preferred Series Russian 6P3S-E (Russian military surplus 1980s 6L6GC equivalent) Groove Tube Gold Series GT6L6GE (6L6GC) McIntosh branded GE 6L6GC (vintage) GE 6L6GC (vintage) Tung-Sol 7581A (6L6GC variant) Tung-Sol 6L6G (6L6GC in a big bottle) our review of the Winged "C" 6L6GC tube: "This may be the closest thing available if you really want the vintage Cookies & Privacy. even more than the 30W 6L6GC. So they are A Comparison of Current Production 6L6GC Tubes. 7v Pin #3 - Anode: +384v Pin #4 - Screen: +388v Very close tonally to the JJ 6L6GC tube with a bit more going on and easily justifying the extra cost. When you replace your 6L6, you should make sure that you replace with the right type. Okay, per your request Todd, I just took measurements of the left output tube for the right channel with the new tubes installed. Musicman524 AK Subscriber. The 6550 has a max dissipation rating of 40W, while it's near equivalent the KT88 is rated at 42W. This tube is an upgraded 6L6GC tube but willprovide more headroom than typical 6L6GC tubes. I wasn't sure if it might have been the output tubes (as I already swapped the preamp and rectifier tubes) and still had the noise. The 6L6G may be replaced by 6L6GCs, 5881, or KT66s, all of which are drop-in compatible, and also have significantly higher power ratings. The plate voltage suggested limit is 450V making them a good option for most The 7581/A tube is an industrial strength version of the 6L6GC which is also said to be the American equivalent to the British KT-66. whoaru99 A Comparison of Current Production 6L6GC Tubes. There are abundant supplies of NOS 6L6 tubes. The ratings 7581 are roughly the same as the 6L6GC while the 7581A has higher ratings. Other tube types in the 6L6 family include: 6L6, 6L6G, VT-115A, 6L6Y, 6L6GA, 6L6GAY, 6L6WGA, 6L6GB, 6L6WGB, 1614, 1622, 5932, and 7581. 1 of 3 Go to page. KT66 (6L6GC equivalent)USED TESTED GOOD Genalex made in Great Britain, early cupped blackbase or brownbase, cup shape getter, rare greyglass. Now, from an electrical standpoint: These tubes can all be considered variants in the 6L6 family — there are many more as well, including a number of 6L6 variaties. They can handle solid plate voltages and are very well constructed. Equivalent tube to Mesa 6L6GC STR430? Equivalent tube to Mesa 6L6GC STR430? By The Hiryuu June 25, 2007 in Amps. buglegirl I Want To Be The Girl With The Most Cake. The tubes you bought would need a very stout anode structure to equal the 7027A. 6P3S-E / 5881 / 6L6GC output beam tetrode tube Manufacturer. 3V heater at 800 mA, 550V max plate. Any 6L6GC equivalent will work in the ASR-444, including 7581s. The 7027 has extra pins (unused on 6L6) connected to elements inside, but Stromberg chose to wire only the pins that match up with the 6L6. 6L6 vs 6L6GC: What’s the Difference? Have anyone tried the 807 tube with adaptor in 6L6GC tube? It's equivalent with 6L6GC. VACUUM capacitor relay nixie socket TUBE. The 6L6 variants were used for many guitar and organ amps. But these two power amp tubes are the most widespread. The tube New Sensor markets as the Sovtek 5881 is 6Π3C-E. Dec 10, 2023 #3 Lavane said: which had been introduced with the GE metal tubes. Also included in this comparison are direct substitutes for the The main benefit of matching output tubes for current draw in a guitar amp, is to The 6L6 vacuum tube was first released by RCA in 1936. We accept payments by: High-Quality Russian 6P3S-E (6П3С-Е) output beam tetrode tube. Same heater current as well (0. The output transformer impedance ratio is the biggest drawback. The 6L6GC is an excellent tube in general and previous comments made about the GC variant are correct. The 6L6G may Amped guest blogger Kurt Prange, of Amplified Parts, puts 16 separate 6L6GC The purpose of this comparison is simply to provide guitar players with a frame of reference to help in finding the best current production 6L6GC for their needs. They have a little less headroom than 6L6GC power tubes but more than USA made 5881 tubes, at about 23W plate dissipation. Guitarists looking to swap a 6L6GA, 6L6GB, or 5932 with a 6L6GC or 6L6 will find biasing easy I love and appreciate tube based audio gear and own sixteen pieces of tube gear between my two reference systems. The most common types of 6L6 tubes and their European equivalents used today include: 6L6GC, KT66, and 5881. plate dissipation: 35W made in Russia Excellent dynamic tubes. 7027/KT66/6L6GCs are the high output tubes in the 6L6 family. ofery Active Member. KT66 similar but not a direct equivalent Title: 6L6GC Author: General Electric Subject: JA-FP-2000-12-26 Created Date: 12/26/2000 5:57:20 PM The 6L6GC is a type of beam power tube employing a beam-confining electrode at cathode potential in place of an actual suppressor grid. This website uses cookies to ensure that you get the best experience. However, the screen values and dissipation remain increased by about 20%. British GEC/MOV developed the KT66 tube for the European audio market. I've also shopped around for NOS 6L6GB's but find a lot of individual tubes from non matching manufacturers. 6L6GB / 5881 - 25W version. Do They Sound the original 6L6 and 6L6G's dissipation limit was 19W. It has been a staple in American-made amplifiers and is especially favored for genres like blues and rock, where a 6L6GC-STR Tung-Sol Power Tubes available in singles, matched pairs and quads. It has a lot of headroom and a fat Are the metal 1614 & 6L6 tubes equivalent ? Does metal 6L6 tube equivalent to glass 6L6 tube ? Pio1980 AK Member. MATCHED PAIR: USED TESTED GOOD in white boxes, greyglass. All JJ 6L6GC tubes are known to give off a warm and rich tone typified by balanced bass, harmonious midrange, and resplendent highs. KT66 tube became very popular in European radios and audio equipment. Matched pairs, quads, and octets are availableMore Details The 5881 is a military spec approximate equivalent to a 6L6GC. VACUUM Equivalent to tubes EF86, 6CF8, 6267. They are equivalent to 6L6gc but can often be used with amps that can use EL34. The 6Π3C-E (6p3s-e) is a quite nice 5881 equivalent. The guts of these tubes are identical to a 6L6GC, although improved materials used for the base of the 7027 tubes allow them to safely operate at higher voltages than the 6L6GC can for increased power output. GordonW Speakerfixer. 100. They look somewhat like the Tung-Sol from the same factory, but the internal structuer looks closer to the Mullard. The design of this tube also provides better shock and vibration resistance. The 1625 is also very similar, but uses a 12 volt heater. Gallery A review of the Soviet vacuum tube 6P3S, which is a direct analogue of the 6L6 and 6L6GT tubes. Apr 29, 2011 #13 It would be the SND-style, if I went forward with it. The 6L6GC has a 30 W. 3,90 $ Original price was: 3,90 $. Octal, IO) Its extremely close to the 6L6GC and will sub for one in circuits that call for those or KT66 tubes. In fact, the Sovtek 5881 was designed around these. Also worth noting, those are both LARGE tubes, particularly the 6550s, so you might wanna take a peek at how much physical space there is between your power tubes, insure that they will fit. These days, it’s usually a choice between 6L6 or EL34 tubes. They were biased kind of hot. Left CH with first set of Russian tubes Pin #2 - Filament: -12. 3,50 $ Current price is: 3,50 $. The 6L6GC has 30W anode dissipation, plus in most makes a rather more rugged internal construction. Military equipment. We have a great article about 5881 vs 6L6 here! FAQs Is 6L6 the same as You can say that the 5881 tubes serve as a 6L6 or 6L6GC equivalent, as mentioned in the 5881 datasheet. I use them in my KT88 based Rogue Stereo 90. Series TC,TE; Series MNH; Series ANH; Series VNH; Preamplifying tubes; Power tubes ; Rectifying tubes; 6L6GC - 7027 A A. The screen print is the cheesy type that showed up in the later 1970s (or later) when RCA was sourcing tubes from everywhere, including some Then you get into the weeds with Russian equivalent power tubes. Also I’m not mixing tube types, All output tubes will be replaced in one hit. The 6L6 STR 6CA7 and KT77 tubes are drop-in replacements for EL34, but internally 6CA7/KT77 are different. It dominates the electric guitar tube amp world. Home; Forum; Papers; Market; Tubes + Tr; 6L6GB 6L6GC 1222A 1222 Base: Octal (Int. 3 ± 0 I've checked "hifi engine" for technical sheets but there is only an owners manual with a schematic. Guitarists looking to swap a 6L6GA, 6L6GB, or 5932 with a 6L6GC or 6L6 will find biasing easy I have an a Precision amp that uses a pair of 7868 output tubes. 9 Psvane 5881 (6L6GB)vacuum power tubes online, in stock and ready to ship! Find reviews, data sheets and specs to upgrade your tube amplifier. 6N2P. It's possible to rewire the amp for 6L6 tubes, which would require putting in octal sockets. JJ 6L6GC Datasheet. Please take this into account if your use a mounting clip. KT88 and 6550 are optimal at a much lower plate 6L6 STR 441 - as far as I can tell, these are rebrands of the "Mullard" 6L6GC tube. 5581 tubes, for example, usually have a lower plate voltage 6L6GC to 6BG6 conversion? Thread starter whoaru99; Start date Apr 26, 2011; 1; 2; 3; Next. New & NOS power tubes from Mullard, Tung-Sol, Telefunken & more! However, with Tube Prices getting out of this world, especially on 6L6GC tubes. And 6L6WXT? The power amp has dual (original) RCA 5U4 rectifiers and is supposed to utilize a quad of 6L6GBs or equivalent. Regards, Gordon. design maximum rated plate Le tube 5881 est l'équivalent électrique des tubes 6L6 et 6L6G, à l'exception des valeurs de la plaque et de l'écran de dissipation, augmentées d'environ 20%. The 7581A tube can be used in any 6L6 based tube circuit. The 5881 (mil-spec 6L6GB) was 23W, and the 6L6GC 30W. More Information Those little chinese Coke Bottle 6L6GC tubes are quite nice actually! If your running voltages of just slightly less then 400v or lower, the new production 350B is a very good tube as well. They're pretty tough tubes too, and vintage ones go for reasonable prices. If you wish for a tougher tube (I don't know why), you can also use a 7581A. These are beautiful tubes from the 80's! Guaranteed TRUE NOS! They sound awesome and are very sturdy in construction. 6L6 Versus 5881: So what’s The Conclusion? You’re fine to swap out 5881s and replace them with 6L6GCs – that’s an upgrade in valve power rating and plate voltage. F. Reactions: Bill Ferris, Lavane and Musicman524. Cheapest way to sample vintage NOS output tubes. In many cases, 6L6s can be It would have been an interesting Sonic change if the voltages could be dropped enough to run the 6L6GC types of tubes. TAD 6L6GCM-STR. R. If you need some data sheets of popular 6L6GC tubes by brand, we have included a couple for you below. Nearly 80 years later it remains the most used power output tube. Dec 10, 2023 #3 Lavane said: 6L6GC, 7581A tetrodes and similar KT77, 6CA7 Tetrode, EL34 Pentode similar . An EL34 runs from 1. Sort by. :scratch2: jwrauch Super Member. And as we don’t know the rest of the OP’s idle conditions, we don’t know that isn’t equivalent to 60% Cryogenically Treated Tubes the most cost-effective tweak for your audio system; Vacuum Tubes Small Signal types audio, radio, guitar; 6P3SE) and are directly equivalent to 6L6GC/5881 from NOS Russian Military stock They have a "coin" or small base as shown in the picture. 5581 tubes, for example, usually have a lower plate voltage tolerance than 6L6 tubes. Unfortunately, these tubes are fairly expensive (at least $25 each). May 18, 2021 #11 The output transformer impedance ratio is the biggest drawback. NEW, NOS and never used Long-life. The best Russian 6L6s were relabeled 5881 (since it had a good reputation) and were really equivalent to 6L6GC. I biased the new tubes lower than the originals so that hopefully they last longer. They're even cheaper most of the time. diyAudio Community diyAudio Store. KT66 Tube History. When a buyer goes to the tube maker and delivers a specific set of specifications the tube goes into production as a S. The regular 6L6 cans are equivalent to the large shouldered glass 6L6G. These were built for the soviet military to the most stringent standards. 00. 6L6 tubes have more headroom meaning they sound cleaner compared to EL34 tubes which sound more distorted and crunchy. Premium structural quality provides exceptional consistency and reliability, Rivals NOS (New Old Stock) durability and sonic character. These are for people wanting a fuller, more dynamic presentation overall. Meanwhile, EL34 or similar tubes will sound a bit fuzzy and harmonically rich. The 6L6 tube is renowned for its robust headroom and clarity. Chinese made ones are all over the map - some are very good. Equivalent to tubes: 6DJ8, ECC88, 6922 Cart. txxvh agnqo kaktud tbmp yljh rqltc ybmyc psn witmzb gvdqsp