Singleended classa tube amplifier design and construction. The first and second stage tube s should be selected for low hum and microphonics. Guitar signal shown in pink enters the tube on the left at ac signal in. Design of the driver stage is concerned with voltage amplification as well as linearity in order to provide the output section with a strong and relatively clean signal. For me, the ultrafi was the last piece of the puzzle in my quest to design an ss amp that can rival tube amps. In this vid, well begin service on an early 60s vintage ampeg rocket 112 combo. Low voltage vacuum tube pre amplifier for guitar from user needs to a commercialized product eric nolan sporer department of product and production development chalmers university of technology summary the vacuum tube was the first electrical signal. A vacuum tube amplifier is a high performance audio amplifier to. The idea with the butterfly nut is not bad since in theory it would be.
Singleended classa tube amplifier design and construction ben verellen, daniel nevistic, and max gorman m. Load line analysis was used to determine the behavior of this stage. However, vacuum tubes are still commonly used in guitar amplifiers. Dsp implementation of a 1961 fender champ amplifier by. And amplifier mod merchants lure us over to their benches with svengali promises of sounding like the latest guitar hero. Some of them are long out of print, and can only be obtained from used book sellers, although they are occasionally seen for sale on the internet. The theory behind the operation of a vacuum tube is based on a concept known as thermionic emission. Following is a list of must have books for the serious tube amplifier designer. Elements affecting this sound include the cleverly designed tone stacks, the. Heyboer told me these will handle 144ma full duty and probably a bit more for audio duty. There are a number of classes and variants of tube audio power amplifiers. Kuehnel gives you the theory and explains how to use the tools to take control of your tube amp circuits in ways. The best thing to do is to simply print out the pdf files and read them each a few times to help the material sink in better.
We will assess the amplifier condition original caps, original 2prong power cord, crusty looking transformer. This is demonstrated by the bewildering and illogical variations of valve amp designs including basic circuit design mistakes, particularly with power valve biasing. Tons of empirical data that demystify the 519 pages tube pdf file guitar amplifier power amps. Pdf first of three articles discussing the fender solidstate twinreverb. Building a brand new valve amplifier using the rh84 design and offtheshelf components. I used them on all kinds of amps from little bitty things up to kt88 and they rocked. The guitar signal flows through the grid stopper resistor to the tube s grid, then out the tube. If you are down with bode plots and circuit diagrams, though, it could serve as a nice introduction to building a class ab amplifier. Design and construction of tube guitar amplifiers by robert megantz this is a great book to get involved in the theory of amplifiers. Aug 10, 2018 the basic theory needed to fully understand the inner workings of a tube amp are explained but the secret sauce is, of course, the online calculators at the publishers website. If youre interested in understanding, designing, or building greatsounding amplifiers and speaker systems, design and construction of tube guitar amplifiers and design and construction of guitar and bass speaker systems contain the information you need. The overall schema of the power stage, including values of all components, is given in figure 48.
And, if we rely on the excellent work of those whove come before us o. Tone stack for guitar amplifier reference design texas instruments. In the center of a tube s glass envelope is a cathode. A tube amplifier has an inherent peaktopeak asymmetry, which can be lessened or increased by varying the slope of the loadline. Many different tone stack implementations exist, but this design uses what is known as the fmv tone stack. Sep 01, 2009 written for musicians, amp builders, and tube audio enthusiasts, design and construction of tube guitar amplifiers provides a complete yet easytounderstand explanation of how to design, modify, construct, and test tube amps. We adopt a pushpull configuration in ultralinear mode. Excellent internet articles discussing the design of guitar tube amplifiers can be found online e. Class b are pushpull amplifiers, similar to conventional solid state amplifiers, where there is a pushing tube and a pulling tube being driven 180 deg out of phase. Although oriented towards valve guitar amplifiers, ax84s free schematics and theory document. Beginning with the ku models in 1945, which were all tubes, and launching a solid state amp line in the late 60s, fender amps have long been a staple choice for guitarists of any genre, including jazz. How guitar amps work and what you can do to start tweaking.
Rca receiving tube manual, radio corporation of america. Verified design tone stack for guitar amplifier reference design ti designs precision circuit description ti designs precision are analog solutions created by tis analog experts. Of course, no lover of tubes should be without the original masterpiece. Fleming used the principle to design the diode, the first vacuum tube. With landmark design work such as the author presents here, the future of the tube amps, which reached their peak around the middle of this century, appears quite strong as we head into a new millennium. Computerbased visualization replaces the traditional litany of mathematical formulas.
Covers how tubes work and how to design circuits around them, with chapters on class aab1 and ab2b amplifier design, power supplies, and more. Twinreverb guitar amplifier in terms if its historic significance, circuit design and. Cliff jacks are isolated from the chassis and must be grounded via a ground wire. So heres a basic overview of how amps work and what you can do to start tweaking your own. The importance of an amplifier s input and output impedance is discussed in ac theory module 7, and using nfb to control impedance is described in amplifiers module 3.
Kuehnel gives you the theory and explains how to use the tools to take control of your tube amp circuits in ways that may surprise you. Keep those filaments lit, design your own vacuum tube. When purchasing a new valve amp, discerning music lovers would select a new amp from 3 or more of the same model. Complete guide to vintage tube amplifiers volume 1 fender.
A valve amplifier or tube amplifier is a type of electronic amplifier that uses vacuum tubes to. Singleended classa tube amplifier aug 10, 2007 2 this configuration serves two major functions. Sep 09, 2017 bg122 a video starting with the basics of reading schematics, slanted towards those involving vacuum tubes. In addition to this concepts including the attraction and repulsion of opposite and like charges play a large part in the operation of vacuum tubes thermionic valves. Design and construction of vacuum tubes amplifier for electric guitar. Reich, we dont even need to tackle any advanced math or taxing mental gyrations to arrive at.
Detailed, complete with plenty of math and drawings. Explores all manufacturers and demystifys the inner workings of tube amps. This study includes information of vacuum tubes history and circuit design, theory of ampli. Resistor noise doesnt factor in much in stages after that. Design and build your own tube guitar amp guitarsite. In preamp stages, the plate resistor determines the loadline slope. Eventually you may want to create a power amplifier. Twinreverb guitar amplifier in terms if its historic significance, circuit design.
The choice of a driver tube is the 12ax7 which is a common small signal tube. It is relatively easy to find introductory information on how to design simple amplifier stages, and it is also fairly easy to find extremely advanced information on complex circuit design, and nearly all of it is. Reading tube amp schematics by rob robinette the sooner you learn to read amplifier schematics the sooner youll be able to analyze classic amp circuits and learn how the masters of amp design voiced their amps. Most of the boutique amps being made today are cloned vintage fender and marshall amps or at least heavily influenced by their circuits. This is in theory an elegant solution, but unfortunately the extra winding requires space. The two most common assembly mistakes are miswired input and speaker jacks. It is intended as a companion to design and construction of guitar and bass speaker systems. Youll want to take notes as you read, but its written with musicians in mind. For me, the ultrafi was the last piece of the puzzle in my quest to design an ss amp. May 20, 2010 but many people who make valve amps appear to have a limited and narrow understanding of valve physics when applied in a circuit.
We figured these are good for about 20 watts single ended. The vacuum tube guitar amplifier still sets the performance standard for the desirable sound of this music production instrument. A bibliography of must have tube electronics books. The p1ex amplifier is a simple threestage vacuum tube electric guitar amplifier. Designing vacuum tube amplifiers and related topics. A theoretical transistor 5 is presented in 1948 by a group of scientists at. Jul 15, 20 the tube used in that case was the cathode ray tube aka crtbetter known today as an old, prelcdledplasma television.
Among users of guitar amplifiers there is a tendency of being enthusiastic about the usage of electron. A vacuum tube amplifier is a high performance audio amplifier to deliver the optimum tone to the listener. Some of this material is general and applies as much to hifi circuits as to guitar amps, but some of it is very. The spreadsheets generated for use with this book are specific to the manual. Book for musicians, amp builders, and tube audio enthusiasts. The most popular jazz guitar amps top 25 survey results. Mar 18, 2019 in this vid, well begin service on an early 60s vintage ampeg rocket 112 combo. This module shows how to simply calculate the values needed to make a working amplifier that has.
Design my design involves a fourstage preamplifier, which uses two dualtriode 12ax7 tubes. If your amp doesnt make guitar sounds at startup check those first. The p1 is a simple tube amp modeled after the classic small guitar amps of the 50s and 60s. Attached please find a table of contents for this class. Vacuum tube amplifier distortion guitar amplifiers based on vacuum tube designs have been known to produce a superior sound to solidstate amplifiers. Any air inside the bulb is thoroughly removed during manufacture, leaving only a vacuum. There are also many books on the subject of tube amp circuit theory, design and building that you can read to help make your first build of boutique quality. If your amp has problems see the tube amp troubleshooting guide.
Fundamentals of amplification this chapter deals with the design and analysis of the basic triode gain stage, which is the main building block of a valve preamp. There are several theories to explain the tube amplifiers specific, distorted guitar sounds as compared to the solidstate amplifiers sound. How to build a tube amplifier rob robinettes car and tube. I started out with the previously mentioned dave hunter bookthe guitar amp handbookas well as tom mitchells how to service your own tube amp. Usually values up to 100k or even more are quiet enough for the second stage grid. Each stage of the real amp has been recreated preamp, tone stack, reverb, power amp and speaker. Ultralinear mode and pushpull configurations were introduced respectively in section 2. Some have exceptional ideas, while others just add a 12ax7 to the input of your marshall. In some short circuit conditions this might lead to lethal accidents. Our new book applies 21stcentury technology to the design of guitar amplifier preamps, power amps, and power supplies. Nutube 6p1, is a vfd which was designed to use it as a double triode. Inside fender and marshall tube amps pdf viva analog. Without going into the theory of these devices, it is adequate to state.
Designing valve preamps for guitar and bass 2 fig 1. More electron tubes can be found in the tube store collection of new old stock nos if you are looking for a tube shop carrying the very best tubes for your amplifier, youve come to the right place. Its designed to be a managable project for the first time builder while still offering a satisfying result. In guitar amps, were not that interested in displaying images with our tubes, but were still very interested in controlling those electronsand we can use a guitar to do it. Tube amp schematics, tube amp information, tube amp projects. Jan 17, 2017 plus, working on your amp when something is wrong can be both fun and rewarding, not to mention possibly essential if youre on the road and in need of a quick fix.
Schematic guitar tube amplifier essentials pdf pages 1 3 text. Another good one that is fenderfocused is dave funks tube amp workbook. I intend this article to be a logical consequence of the fine inventions of the 50s and i continue those lines of thought by bringing some new ideas at the end of the millennium. Introduced by fender in 1957 in the 5f6 bassman, it was later copied by marshall, vox, and many other guitar amplifier manufacturers 2. Pdf first of three articles discussing the fender solidstate twinreverb guitar. If youre here then youre probably thinking about tinkering inside one. An easily constructed highquality singleended 8w amplifier using standard valves and the. This the first video of many on design and build of an audio tube amp. Under the bridge of the guitar there often is a grounding cable, which makes you part of the electric circuit when touching the strings.
Schematic guitar tube amplifier essentials pdf only pedal or amp that can introduce cut and real tube boost to those critical frequencies. Pdf revisiting the amp that gave solidstate a bad name. Building your own guitar amp is a rewarding pastime, but learning how to do it can be time consuming and frustrating sometimes. It carries just a slight positive charge, and its ready to release a gazillion electrons. Lets start by looking at the simple standard tube amplification circuit that you will see again and again as you study tube amp schematics. Output transformers dramatically increase the cost of a valve amplifier circuit. Low voltage vacuum tube preamplifier for guitar from user needs to a commercialized product eric nolan sporer department of product and production development chalmers university of technology summary the vacuum tube was the first electrical signal amplification device.
Coates 2007 2012 class a amplifier design introduction to amplifier design basic design process. Covers all the essential of tube electronics design, including the basics, tube theory, load lines, amplifier design, etc. Another useful resource is designing tube preamps for guitar and bass by merlin blencowe. Basic theory a 21stcentury approach to understanding preamp, power amp, and power supply design fundamentals of guitar amplifier system design a structured methodolody for crafting an awesome guitar amplifier. The slides are pretty heavy on engineering design terms, but give a good feel for what it takes to construct and tune an audio amplifier using vacuum tube technology. Ill have a sound clip of my current amp design project, an ultrafi ss guitar amp that sounds pretty amazing. Fortunately, solidstate and tube amplifier circuits share a lot of similarities. If you arent sure about which valve you need, or what tubes you can substitute, let us help you. Once the dspbased design is completed for this small amplifier, the algorithm can be reconfigured for other vintage vacuum tube amplifiers. The design of basic tube power supplies is actually very straight forward. How to design valve guitar amplifiers the valve wizard.
Design and construction of vacuum tubes amplifier for. Ax84 p1 tube guitar amplifier project classic projects current version testing version old versions overview. The basic theory needed to fully understand the inner workings of a tube amp are explained but the secret sauce is, of course, the online calculators at the publishers website. Fleming used the principle to design the diode, the first vacuum tube patented in 1904.
Class ab amplifiers are the most common in larger guitar amplifiers because of their efficiency. Understanding vacuum tube amplifier schematics basics. Real time tube guitar amplifier simulation using webaudio. Lots and lots of helpful people can be found on my amp forum. My tube amplifier and guitar help forum amplifier service technicians listing tube amp schematics and layout diagrams everything from acoustic to wurlitzer pdf tube amp. The science of electric guitars and guitar electronics. Profusely illustrated, the book uses graphic aides and basic algebra. Btw, hopefully by the end of this year, ill have a sound clip of my current amp design project, an ultrafi ss guitar amp that sounds pretty amazing. Vacuum tube circuit design pdf file 512 pages revered as much as ones guitar, the fender amplifier gets its. Also the inconsistencies between valve amps made it difficult for active systems greater than 2 way, to evolve. Since tube guitar amplifiers are the easiest thing in the world to play with, many gurus have come out of the woodwork. Audio transformer design for tube amplifier with improved quality and reduced cost project team.
A number of recent visitors have registered surprise that we do not have any music playing in our workshop. Most of these free music theory lessons contain a free pdf download that contains the actual tutorial. A thermionic valve or vacuum tube contains two or more electrodes suspended inside a glass bulb. Many amps of the same model could vary considerably.
The power amplifier involves three stages, two of which use a 12ax7. Written for musicians, amp builders, and tube audio enthusiasts, design and construction of tube guitar amplifiers provides a complete yet easytounderstand explanation of how to design, modify, construct, and test tube amps. Any air inside the bulb is thoroughly removed during manufacture, leaving only a. An easily constructed highquality singleended 8w amplifier. Electron vacuum tube guitar amplifier semantic scholar. Vacuum tube guitar amplifier rutgers university, electrical. Dsp implementation of a 1961 fender champ amplifier by james.