The direction of the 8pin octal tube sockets for 6sn7 match with the screen silk of the board as in figure 2. Then plug in two delicate 2a3 tubes and connect the output transformer as following block diagrams, either openloop or negative feedback. The 2a3 tube was introduced in 1932, designed specifically for the audio amplifier output stage. One set of variablesdesign will not be able to maximize the full potential of two different tubes. Bjt amplifier amplifier 2a3 audio amplifier class a amplifier swamped amplifier sensor amplifier power amplifier peugeot jbl amplifier dc coupling amplifier operational amplifier amplifier repair audio amplifier amplifier design amplifier mcq pdf download multistage amplifier tube amplifier tube amplifier design rogue cg30r amplifier class d power. Page 34 the next part we need to concentrate on the lm1084 regulators need to be installed on the board. Rca 2a3 power amplifier triode the 2a3 is a threeelectrode, highvacuum type of power amplifier tube for use in. Sovtek 2a3 datasheet pdf download adobe acrobat pdf reader. The 2a3 tubes are electrically similar to two 45s in parallel. Version 1 uses two 6sn7s in the input stage, and delivers full output with around 300mv input.
Warranty information and return policy warranty period. Frank combined many techniques, resulting in a suberb sound quality. Rca 2a3 tube 2a3 2a3 power triode triode pushpull class c tube amplifier power transformers rca tube 2a3 scans0017378 triode pushpull circuit rca tube text. I bought this unit in 20 when i was driving home from black sabbath concert in czech prague, previous owner liked it a lot, but he didnt owned appropriate speakers to make a good match with relatively low power. The plate can do 28watt, but to get this, you need to modify the amplifier. The kr audio 2a3 hp tube is fully compatible with any well designed 2a3 amplifier and sonically delivers exactly what owners of these special amps expect, and then some. These tubes produce an enveloping soundstage and have a tonal balance that is a little bit fuller than typical 2a3s. Feel free to send us your hifi audio schematics and we will add them here. Well, ike persuaded me to choose the jj 2a3 40 tubes for my pbbuilt amp, and got them to me in two days along with a sixmonth warranty. Download a pdf file of all 211 pages at once by clicking here. Pure sense of space with all subtle timing cues intact make this a tube of choice for any 2a3 enthusiast and an excellent upgrade path for any exiting 2a3 based system.
Tube amplifier project page after restoring a nice old 1938 sparton model 1568 console radio, i was so impressed with the quality of the sound that i started looking into building an amplifier using the same 2a3 output tubes that the big console uses. Single plate 2a3s were made by cunninghamrca, sylvania, tungsol and arcturus. High voltage for the tubes uses a fullwave tube rectifier into a. This is our collection of diy and hifi audio schematics. Both are ss rectified, so my only options aside from rolling the 6922input tube of the audion and the 12au7 tubes of my bottlehead preamp were rolling the driver tubes. Substitutes are given as a guide only please refer to original manufacturers data sheets to ensure that a substitute is safe and appropriate for your application. If no any abnormal events, turn off the power and wait several minutes for capacitive discharging. The drive circuitry of the control grids is not shown i assume perfect. I have tried the amplifier with rca 2a3s dual plate and shuguang 2a3s. Cary audio design cad2a3si operating manual pdf download. This is the only design that will safely put the 45 tube in its best working operation point, because this is designed and engineered with the 45 tube, instead of the more powerful 2a3 tube. View and download analog metric 2a3 user manual online. This product has a universal power transformer and can be used worldwide by following the wiring instructions in the manual.
I do not know why but i prefer simple, low power triode designs. Antique radio forums view topic tube substitution for 2a3. They are in white us military boxes and are penta branded. Due to popular demand, a version for spice 3f4 compatible engines is now available for download.
The input stage of the stereomour ii consists of a pair of 12at7 tubes. The bigger holes of the 4pin plate sockets correspond to the pin1 and pin4 of 2a3 tube filament voltage. I chose the 2a3 directly heated triode power tube to implement the loftinwhite circuit. Thats how i wound up with some uncommon tube choices. Sovtek 2a3 is a close replica of classic american 2a3 tubes, excellent for classical sources. The 2a3 evo after ten years of revolution on the original 2a3i, we have settled with the finest hifi transformers hashimoto of japan. I think the 2a3h was introduced with the radio but was available for only a short time. Vacuum tube valley vtv was a magazine produced by charlie c. The 2a3s will bias exactly at the original operating point. Unfollow 2a3 amplifier to stop getting updates on your ebay feed. Power tube selection charts for highpower audioamplifiers. The entire 1945 taylor tube catalog in pdf format note, 1.
One half of the 12at7 is configured as an actively loaded voltage amplifier using our camille cascode constant current source for super quiet, dynamic, linear performance. For files in adode pdf format where indicated, if you want to download the file and view offline, click on the link with the right mouse button, then click on save link as. The prospective music customer is in the market for the vintage sound reproduction. Bottlehead stereomour kit thinking about building a 2a3. Hickok documentation, manuals, schematics, and catalogs. The circuit shown in figure 1 shows the complete power supply and one channel of amplification. Single plate 2a3 s were made by cunninghamrca, sylvania, tungsol and arcturus. Despite being relatively low powered, 2a3 still is the triode of choice for many highend audio amplifiers and diy projects. Stereomour ii stereo single ended integrated 2a3 amp bottlehead. The choice of input and driver tubes was made experimentally. Adding this vintage tube will help enhance sound quality, provide simple amp transformation and upgrade existing speaker configuration. The av 2a3 sl is a direct replacement for the rca 2a3 monoplate tube.
This is my first self made tube amplifier using directly heated tubes. Make offer lafayette 2a3 tube tested excellent 6034 and plate current 64 no shorts, gas. My speakers are diy cornscalas and my current amp is a wyred 4 sound sti integrated which is fantastic and is staying in my system. If you have built any of these circuits, we would love to hear from you so send us your comments. Then the replacement tube 3rd began acting up within a few hours. Some of our competitors claims to be the only one with a center tapped filament, but at eml we build since many years all tubes center tapped, not just this tube. Ua 450 v wa 40 w maximum plate curent of everage tube for fixed bias ia 70 ma maximum plate curent for manually. It is interesting to note that both of the tube dealers that i called have never heard of nx483s. If you want to build a bottlehead kit, though, the news is good. This is a new model which is designed to offer significant increases in accuracy over previous models that we have made up, or which have been referenced here.
The big question with these tubes has to do with compatibility with the amp. This is the most liquid silky high end sound you can hear. This almost killed a pair of 2a3 tubes and made some very strange noises come out of my speakers. Legendary rare electube 2a3 tube fivre single plate top end. Vintage tube output benefits guitarists, concert venues, and even. My initial design already included a regular 1n4007 diode from grid to ground to prevent the 2a3 from going into class a2. We obtained over 150 pieces of these nos penta 2a3 tubes. The 2a3 vacuum tube is a power triode capable of outputting 3. High evacuated tube, it achieve high performance tube in audio frequency. This one has a lot of pages from the european philips tube manual. Inspired by the kismet 3 by fabio camorani, yet with different power supply and driver tube. Not only is the 2a3 s the little engine that could, triode lab is the little company that can. The sovtek 2a3 tube is a high quality tube at an affordable price.
Two triodes can be used in class a and ab amplification. All our tubes are guaranteed for 3 months from the date of purchase. Electroharmonix 2a3 eh gold grid datasheet pdf download adobe acrobat pdf reader. I was sent a replacement tube and while waiting, the other tube started making noise. Sun audio 2a3 tube integrated amplifier audio illuminati. Tubes with part numbers beginning with 2a3 tube are in stock and ready to ship. Double triode ecc99 is a 9pin double triode usually used as a driver for directly heated power triodes i. They looked the same pin wise and i saw the differences in the voltages but wasnt sure of the meaning. May be its the warm sound produced by these tubes or because i like horn speakers and i know that this relation is erotic. However, they carry a high price tag due to their rarity and demand. Builtin tube 5z3p5u4g and solidstate rectifier and regulation circuitry with two inductors option in clc. Order electroharmonix 2a3 eh gold grid vacuum tubes online, in stock and ready to ship. Legendary rare electube 2a3 tube fivre single plate top endtriode in box 1930s.
The anodes are connected to the primary winding, the cathodes to ground circuits 1, 2, and 3, and the middle of the primary to the highvoltage supply. Here is the story about my beloved, tiny hercules sun audio 2a3 integrated amplifier. This great amplifier is a classa, pushpull amp using a pair of 6b4g directlyheated triodes as the output stage. Its better suited to your application, its better suited to the first time builder, and it sounds surprisingly good. This circuit is a classic 6sl7 tube wired in seriesregulated pushpull, driving a 2a3 directly heated triode for about 3 12 watts of output power per channel. No distortion cancellation going on here other than the pp 300b pair i tweaked each stage individually for the lowest possible distortion. This kit employs commonly used triode 2a3 vacuum tubes in pushpull configuration. This amp uses a pentode first stage dc coupled to a cathode follower to drive the output tubes, and no. Triode lab orangetriode lab satin blacktriode lab classic dark gray gloss, or custom paint for extra 3 months wait. I have tried the amplifier with rca 2a3 s dual plate and shuguang 2a3 s. Find great deals on ebay for 2a3 tube and 2a3 valve. The output stage uses two 2a3 tube configured as push pull. View and download cary audio design cad2a3si operating manual online.
Detailed and clear sound provides real musical reproduction. They also noted excellent midrange imaging, and overall tonal balance. The direction of the 8pin octal tube sockets for 6sn7 match with. Stereomour ii stereo single ended integrated 2a3 amp.
Vacuum tube valley magazine get the entire 20 magazine set. One half of the 12at7 is configured as an actively loaded voltage amplifier using our camille cascode constant current source. Just purchased a 2a3 seth with old electro harmonix tube, i want to update them. You can use in auto bias mode different cathode resistors, p. Figure 1 shows several pushpull tube amplifiers only the power tubes and the output transformers primary winding. Low gain edition 2v input sensitivity with full suit of hashimoto sansui transformers, with max of 4.
I looked at the tube specs and im not sure when i am reading them what are the important items. Singleended triode set 2a3 tube amplifier schematic. The schematic is from the book build our own audio valve amplifiers by rainer zur linde. For other taylor tubes, see the entire 1945 taylor tube catalog in pdf format note, 1. Diy audio projects forum 2a3 amp modified for 45 tube. Hi folks, i have no experience with tube amps so i would like some advice. Sadly, charlie kittleson passed away on february 10, 2009. Without modifications, you just plug in this tube into any normal 2a3 amplifier, and tube and amplifuer will work at the normal 2a3 operating point.
The 2a3 tube amplifier a tribute to simplicity and warm. This 2a3 singleended triode set tube amplifier uses a ef86 input stage and a solid state power supply. Im looking to get a tube amp to add to my set up for those times in which i dont feel. The reason being that i did not have these components when i started the project. Any exceptions will be noted on that tube s warranty tab. Nov 09, 2009 in my amp, the best sound 2a3s have been eml meshplates. The 2a3 tube, which produces around 5 watts, consists of a singleended triode amplifier utilized mainly for output stages of audio power amplifiers. With the kenrad 2a3s mentioned in my above post i ended up using thinner sounding european 12at7s to somewhat balance out the sound of the fat sounding krs. The 2a3 s have more bass and slightly more power than the nx483s. It is direct heating cathode and low power consumption. The 2a3s have more bass and slightly more power than the nx483s.
Amplifier repair bjt amplifier amplifier tube amplifier sensor amplifier dc coupling amplifier amplifier mcq pdf download amplifier design multistage amplifier 2a3 audio amplifier operational amplifier audio amplifier peugeot jbl amplifier class a amplifier power amplifier swamped amplifier class d power amplifier common emitter amplifier. They sounded great for 2030 hrs, then one started acting up. This is the output of the filament board that will carry the 5v dc to the 300b tube. The sex kit is cheaper, easier to build, and quieter than the stereomour.
When you intent to get the maximum out of a 300b, and operate this tube at the limits of safe operation, it is a better idea to use the 300bxls in such a case. If youre dying for a 2a3 amp, though, the spendier paramounts might be what you want. Sound even more detailed than 300b, with great tone separation. Lafayette 2a3 tube tested excellent 6034 and plate current 64 no shorts, gas. To view this site, you must enable javascript or upgrade to a. In this project, the 2a3 power tube runs at a 60ma plate current with no signal applied and has a 410v plate voltage.