In addition, some files are archived, so you need winzip or winrar to open that files. This 20 watt williamson type amplifier employs the famous acrosound. The original williamson amplifier was described in wireless world uk in april and may 1947, and updated in august 1949. This page is dedicated to the williamson amplifier, which is regarded by audiophiles as one of the great moments in audio history its intent is to present a tribute to the contribution of mr. One of these was the famous williamson amplifier circuit. A variation on this amplifier was published in audio engineering magazine in the us in november 1949 and reprinted in audio anthology, vol 1 an ultra linear version was published in audio engineering in november 1951 and reprinted in audio anthology, vol 2. Uses a pair of 3500zg tubes with variable input tuning and pinetwork out.
The amplifier designed by pascal jansen project chapter 8. Easy to build and easy on your pocketbook, this true high fidelity amplifier will get the most out of your high fidelity system. Use sangamo dry tubular electrolytics for troublefree. Spoiler alert, john has added bootstrapping to the pushpull amplifier which follows the split load phase inverter in the standard williamson circuit. Heathkit diagrams, schematics and service manuals download for free. Also some files are djvu so you need djvu viewer to open them. Originally published as a booklet, the williamson amplifier is presented on cd in adobe acrobat pdf format. To open downloaded files you need acrobat reader or similar pdf reader program.
Here is my williamson with two kt88s per channel operating at about 50 to 60 wpc class ab1. Audio transformer design for tube amplifier with improved quality and reduced cost project team. Back then i never heard of the williamson tube amplifier circuit. Sb220 heathkit amplifier converted to six meters 1kw cw and 1. Descriptions of it have been published in all the principal countries of the world, and so there are. The noise in this amplifier was, however, almost entirely 50 hz hum, caused by. Diy audio projects forum the big high power williamson. Sep 20, 2018 a good guide for building an ultra linear amplifier utilizing stancor transformer a8072. Jun 04, 2011 please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more. Building an amplifier is an important step in the experimental part of the project. He has presented a fully tested circuit which could make it possible to build a low distortion amplifier with no or very little negative feedback. Had classd amplifier designs not arrived on the scene, no doubt that classg would be far more popular today. Also included on the disc, partridge amplifier circuits.
Service manuals, schematics, eproms for electrical technicians. Output audio transformer design the output transformer in a singleended tube amplifier is the device which matches the highoutput. Williamson to tube audio, and to provide information to users and diy constructors of the features, advantages and disadvantages of this amplifier. A good guide for building an ultra linear amplifier utilizing stancor transformer a8072. Over 5,000 of them have been built in a little over one year. These changes improve performance by increasing power handling capabilities and extending the margin of stability. Click here for schematic of this homebrew williamson amplifiera variation of the kiebert 1952 schematic designed and hand drawn in 1959. This is no longer a begun project, it is now official. It is not the circuit alone, but the properties of the valves and such components as the output transformer together with the welding of theory and practice into a. Every tube in this system is a triode including the mcintosh c20 preamp that is used to drive this project. Heathkit claimed the dual chassis design gave more versatility for layout, though hum reduction may have also played into the reason.
We have complete set of parts to make a pair of williamson valve amplifiers. Modernize your williamson david haller dyna company reprinted from audiocraft, january 1956 modernization of williamson type amplifiers can be readily accomplished by use of new components and circuit modifications. Aug 30, 2016 this project is called the coley w225. Williamson amplifier, a type of pushpull audio amplifier with low distortion first designed in 1947 williamson road junior public school, an elementary school in toronto, ontario williamson ether synthesis, one of the most common methods for preparing ethers. Assembling and using your heathkit williamson type amplifier. Now, in the museum, we have the two original magazines showing both parts 1 and 2 of the original williamson articles and these detailed the full designs of the williamson valve amplifier. Spectacular vacuum tube audio amplifiers currently available. Continuous oscillation will occur in a feedback amplifier if the loop gain that is the transmission of the amplifier and the feedback network is greater than unity at any point where the phase shift of the amplifier has reached 1800. Articles from wireless world on the willamson amplifier keywords. The williamson amplifier an interesting link vinyl engine. Antique radio forums view topic williamson amplifier. Aqua blues outer limit amplifier with 845 output tubes. It is on a 10 by 17 by 2 chassis and weighs 42 pounds. Also power supply has been upgraded to harbach electronics which includes new filter capacitor block, new retifier.
I like the fact that they include schematic and propose a layout that is easy to follow. These im povements again correct for limitations with respect to power output and. Three stancor transformers are used in the famous williamson circuit. It is a twochannel, 25w williamson amplifier using ultralinear output transformers. A williamson amplifier refers to a type of vacuum tube valve amplifier whose circuit design uses the same principles as a design published by d. And like womenamplifiers come in all sizes, shapes, and degrees of appeal. Welcome to the most complete do it yourself guide on the d. Heathkits first williamson type amplifier was the w1. This 20watt williamson type amplifier employs the famous acrosound. The williamson amplifier onew versiono from wireless world august 1949 p. Assembling and using your heathkit williamson type amplifier author. The article by cathode ray in the may, 1949, issue, states the matter simply and with characteristic clarity. The williamson circuit became justly fa american radio history. Amplifiers and superlatives an examination of american claims fo r improving linearity and efficiency by d.
Its a collection of reprinted articles about its design, including schematics, specifications and construction tips. A williamson amplifier is a type of vacuum tube valve amplifier whose circuit design uses the. The noise in this amplifier was, however, almost entirely 50 hz hum, caused by coupling between the mains and output transformers. The williamson amplifier revisited there is no single answer to the question of whether audio amplifiers using transistors are better than those using valves or vice versa. Media in category williamson amplifier the following 11 files are in this category, out of 11 total. Free heathkit diagrams, schematics, service manuals. Each channel uses a pair of 6sn7 dual triodes driving a pair of fixed bias 6l6gc output tubes.
Electricity from the mains was free, to me at least, whereas hightension batteries had to be bought from my pocket money. Introduced by wireless world in 1947 as merely one of a series of amplifier designs, the williamson has for several years been widely accepted as the standard of design and performance wherever amplifiers and sound reproduction are discussed. The williamson amplifier cd british audio products online. Now i know i all ready have a thread for this amplifier, but this time i am with in the testing process. Shown above is a pair of williamson output transformers, a pair of williamson mains transformers and many other items.
Block diagram of williamson amplifier circuit design. An adaptation of a famous english circuit which has already earned an enviable reputation for quality. Block diagrams of circuit arrangements discussed in the text. Walker recent articles, particularly in the united states, have shown that some confusion of thought exists about the goodness of an amplifier for reproducing sound. A williamson amplifier is a type of vacuum tube valve amplifier whose circuit design uses the same principles as a design published by d. The second is normally held at a positive potential, but a capacitor to ground keeps it free from signal and so it screens the control grid from the anode. Beyond that power delivery, the mosfets all the rail voltages to expand, allowing the amplifier to deliver four times more power. Voltages underlined are peak signal voltages at 15 watts output. Heathkit w3am williamson amplifier sch service manual.
Audiolab of georgia many parts and free nte crossreference software. A 25w stereo williamson amplifier parts express project. In pentodes, such as the ef86, we find two more grids. Just click on any of the above images to download a pdf of the user guides. The stancor\nilliamson amplifier has become the audiophiles favorite. Af gen and hp330b distortion analyzer, with original manuals, all for free. The articles gave the rationale behind the design, the circuit and. These williamson parts have been in the collection since 1992. Top view of amp featuring partridge cfb output transformer. A collection of articles reprinted from wireless world on design for a high quality amplifier david theodore nelson williamson on. Williamson proposed the standard which became generally accepted as the target figure for highquality audio power amplifiers, for less than 0. Shuricht electroniccomponents catalogue from germany.
Williamson amplifier built to the design in wireless world, 1949. The williamson amplifier introduction introduced by wireless world in 1947 as merely one of a series of amplifier designs, the williamson has for several years been widely accepted as the standard of design and performance wherever. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more. Now, as always happens, progress in amplifier design has continued. My early work culminated, in 1951, with the assembly of a luxurious kit for the highly esteemed highfidelity williamson 15w amplifier design. As shown at the top of this section, reprints are still available of the williamson amplifier wireless world publications. A 25w stereo williamson amplifier parts express project gallery. The williamson amplifier introduction introduced by wireless world in 1947 as merely one of a series of amplifier designs, the williamson has for several years been widely accepted as the standard of design and performance wherever amplifiers and sound reproduction are discussed. Web site with links to over 975 electronic component manufacturers. Williamson and was first published in the spring off 1947 in wireless world. A triode amplifier build from an acrosound transformer book. Aug 06, 2015 a triode amplifier build from an acrosound transformer book. The williamson amplifier is a design by the british engineer d.
The williamson amplifier revisited elektor magazine. Heathkit schematic and manual archive vintage radio info. The output transformer is an important part of the amplifier requiring a thorough parameter determination. Set up for 240 volt operation and optimized for 50.
In the amplifier tested, the measured noise level was 85 db below maximum output. Buy, sell, trade hf and vhf equipment, towers, antennas, rotators and more. Descriptions of it have been published in all the principal. The biggest and best ham radio classifieds on the web. Search wikipedia for williamson amplifier and learn about it. Since the publication in the april and may, 1947, issues of wireless world of an amplifier design suitable for highquality reproduction of sound, correspondence has revealed that a more complete explanation of. Williamson amplifier engineering and technology history wiki.