The 12ax7 is one of the most widely used double triodes in audio circuits. Heater voltage vf 6,3 12,6 v heater current if 300 150 ma. The power amplifier involves three stages, two of which use a 12ax7, and the last of which runs through an el34 pentode tube. I will first attempt to describe each version and provide data for each. Ecc83 is the european designation for the 12ax7 tube it is the same exact tube. You can use acrobat for viewing and printing pdf files. The most significant difference between the two is that 6n2p has its two filament elements connected in parallel, unlike the series filament connection of the 12ax7, and it is thus only possible. Pdf 12at7wc mile11097e mile11097d 000microsecond 12at7wc. If you look closely at all the sheets, all conditions listed for the 12ax7 are identical to the 12ax7a and the 7025. Step 1 feed the three 114 length of wires from the wire bundle into the opening in the tube socket base. A comparison of current production 12ax7 tubes 2014 frequency response separated into three ranges t 12ax7 mul lows mids highs 12345678910 10 3 noise 1 low noise 4 high noise gain rating 110 drawing drawn to scale. The 12ax7 is a miniature highmu twin triode each section of which has an individual. I will also briefly discuss the real meaning of a nos tube, tube faking, and overcharging for tubes by some dealers. Then, i will follow up with short descriptions of some that i.
It supports both mm or mc phono input with riaa compensation. However, in reality there are comparative gain differences among 12ax7s. It was developed around 1946 by rca engineers in camden, new jersey, under developmental number a4522. Full 1951 tube manual 364 pages, 15mb pdf file introduction forward, table of contents 89kb tube data section 1 0a3 through 6b4g 3. Key data and drawings are shown below, or you can download the 12ax7 datasheet in pdf format. We suggest the electroharmonix or philips tubes for more vintage tone in fenders, and other us made guitar amps. After the original 12ax7, additional variants were issued with various industrial numbers including the 7025 as well the 12ax7a. Each cad and any associated text, image or data is in no way sponsored by or affiliated with any company, organization or realworld item, product, or good it may purport to portray. For instance, 6l6wgb takes you to the same file as clicking 5881 the 6l6gc parent. Prior to this test, tubes shall be preheated a minimum of 5 minutes with all. I think that the 100 gain factor universally referred to the 12ax7 tubes is the max gain factor this tube can reach so my question is if the 6n2pev tube may be considered to have the same gain factor, a higher gain factor or a lower gain factor compared to the 100 gain factor of a 12ax7 tube.
Download the zip file and extract the files to where you normally store your ltspice schematics. The 12ax7 is a miniature highmu twin triode each section of which has an individual cathode connection. The only claimed changes are lowered hum, lowered noise and microphonics in some sheets. Eirc electronic tubes factory data sheet ecc8112at7 page 1 of 4 telephone. Alternatively, you can grab the zip file with all daves models, and some other stuff such as a heater model and some test circuits. If you cant find what you need here, try duncans tube data sheet locator. The balanced tone of the jj 12ax7 works well in any amp.
It is popular with tube amplifier enthusiasts, and its ongoing use in such equipment makes it one of the few smallsignal vacuum tubes in continuous production since it was introduced. Ecc8112at7 page 1 of 4 franks electron tube data sheets. Eirc electronic tubes factory ecc83 12ax7 ecc83 is a. Double triode data sheet page 1 of 4 quick reference data anode current ia1,2ma. Ideally, every 12ax7 should yield the same gain when placed in the same circuit. This manual is the better one for loctal data some types were moved to obsolete status and into the condensed data section by 1959. Step 2 press the stripped and tinned end of the black wire into pin 8 along with the 1. The double triode is especially suited for use in resistancecoupled voltage amplifers, phase inverters, multivibrators, and numerous industrialcontrol circuits where high voltage gain is desired. The spiral filament was the new design element, and was responsible for. Here you will find our collection of quad tube amplifier schematics. The 12ax7 was originally intended as replacement for the 6sl7 family of dualtriode amplifier tubes for. Here youll find manufacturers data sheets and curves for many popular and some not so popular electronic valve types. Pair of vintage sylvania 12ax7aecc837025 vacuum tube, made in usa 15643473798.
The models marked dm are ones ive made up from data sheets or actual testing. All of these pdf files are available for free download. A centertapped heater permits operation of the tube from either a 6. Developed by rca and released in september of 1947, the 12ax7 is a high gain low noise tube that is the most popular tube used in inputinterstage audio. The use of a single tube in the output stage of the power amplifier is commonly referred to as a singleended design.
I dont have any particular insight about currentproduction engineering sorry to say. This graph is based on the average gain and noise measured from different tube brands using the same number of samples for. On the 7025 it was made specifically for audio use but fender didnt engineer or produce tubes, and touted as low noise and low hum by rca and sylvania, but rca and sylvania made no claims of low microphony though sonotone did. Pdf 12ax7 12au7 51j4 6ak5 tube 12ax7 6ba6 tube diode me c108 scansu9x26 9 pin tube socket 12ax7.
Vacuum tube 12ax7 ecc83, jj electronics amplified parts. The current flowing from anode to cathode is called the anode current, ia, and the voltage measured between anode and cathode is called the anode voltage, va or more accurately vak. If the anode voltage is negative, electrons will not be attracted to it and no current will flow. It uses four 12ax7 vacuum tubes in serial commoncathode configurations and buffer stage to provide sufficient voltage gain for. Double triode quick reference data anode current ia1,2ma transcoductance s1,6mav amplification 100 heating heating is indirect by ac od dc, with serial or parallel supply. Its rugged design and rich harmonics make this tube an obvious choice for musicians who need a reliable and high quality tube at a reasonable price.
This design was chosen for its relative simplicity compared to the more. I still dont know the manufacturer of this particular tube. The 12ax7a is a miniature highmu twin triode each section of which has an individual cathode. Eirc electronic tubes factory data sheet ecc83 12ax7 page 1 of 4 ecc83 is a. Ive done that before with electricallysimilar e180cc, and the character change is bold. Double triode ugv uav4 3 2 1 0 0 1 2 3 4 5 6 0 50 100 150 200 250 300 350. Another example with a pair of el346ca7 being driven by the ecc8112at7 as a preamp and phase splitter in guitar amp style. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. Socket 9pin to12ax7, 12au7, 12ay7, 6j8 3d cad model. In most cases, they can all substitute for each other. I dont think i would use it as a replacement for a 12ax7, but i might try it for a phaseinverter on an amp that uses 12at7 there, for a cleaner sound. Gec twin triode,alldatasheet, datasheet, datasheet search site for electronic components and. For zerobias data, generator impedance is negligible. It was released for public sale under the 12ax7 identifier on september 15, 1947.
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