JLH Memorabilia -- The Past Perfect!

Annals of a Life in Tech :: 1

John Linsley Hood -- a name that refuses to fade into the sunset as far as the tech world and the DIYers are concerned. It has been more than half a century since JLH came into popularity among audio DIYers with his classic "Simple Class-A Amplifier. Despite the passage of these long decades, the interest in the little amplifer has refused to die; on the contrary, fresh interest and enthusiasm among the DIYers, particularly the younger set who were not even born at the time, is kindling renewed interest in the design by the Master, and a concomitant search for his broader technical output.

        One thing I have noticed while on the discussion Forums is the fact that the name JLH, though familiar to most, does NOT sort of "ring the proper bell", so to put it. People just know him as the designer of the classic little amplifier which has managed to maintain its popularity over the decades by sheer luck, perhaps. Period. Then there are the 'Simulation Honchos' who do their bit on the desktop, and then pronounce their mighty judgement on most things under the sun, including the JLH classic amplifier. But there are also the poor souls who ask about the other designs (if ANY!) of JLH and would like to build some other more powerful amplifier than this teeny one.

        Truth be said, despite the Web being all-pervasive, it is not easy to dig up original material that is half a century old. Archives do exist, but many of the old links and references are dead for all practical purposes. So when I decided to cobble up a "Tributes" page for JLH, I was in a real dilemma -- should I concentrate on the classic Class-A, or should I decide to have a comprehensive repository of most of the JLH material. I decided on having both, as the material on the class-A amp and related stuff is voluminous enough to demand a separate set of pages for itself. Of course, that took priority and it has been posted in my blog (kindly note it is work in progress, and more material is being added):

https://jlhclassicdesigns.blogspot.com/2024/11/the-jlh-gateway-golden-jubilee-tribute.html

        Now what remains to be done is to collect together the truly voluminous and varied material that has flowed from the pen of JLH over the few decades that he was active in the field of audio design. A cursory look at just the titles of his articles will tell the sceptics one thing -- his depth of knowledge and his grasp of technology and his original approach was phenomenal indeed. To read his articles is to get a fresh insight into the topic, to feel that you were being hand-held every step of the way by a true master. This will prove to be an eye-opening experience, particularly for those who have, largely through ignorance and indolence, under-estimated the great man.

The JLH Memorabilia

        My attempt here is to bring together, perhaps for the first time, authentic archival material of the published articles in the technical Press of the late John Linsley Hood. I am happy and proud that I have been able to track down most of it, though a sizeable chunk still remains inaccessible, which, hopefully, could be remedied in the future. The 'JLH Memorabilia' pages will serve as a gateway to the corpus of the work of JLH, with some introductory commentary about the contents selected and highlighted in each post. I am hoping that this will indeed prove to be a "panoramic single window"  through which it will be possible to appreciate the true stature and greatness of JLH as an engineer and designer par excellence.

A Life in Electronics

Typical Crystal Radio

        What more could be a better introduction to JLH than what he has penned himself regarding his life and growth in electronics, from a wide-eyed eight year old getting his hands on his grandfather's old crystal radio and taking it home (for experiments!), to one of the greatest audio Gurus of all time. 

Galena Crystal Detector

        The 1920s and '30s were the times when radio was occupying the fancy of people the world over, and the young JLH was lucky to be introduced to it at an early age. HIs innate curiosity and quest for knowledge led him onto many rewarding discoveries, as he sums up in the article. By the time he was an employed young man, he had built the rightly famous 'Williamson Amplifier', which was to remain his primary instrument for entertainment, until the augury of stereophony in the late 1950s. The size constraints and the cost of adding another channel of valve amplification to his existing music system led him to explore the possibility of turning to the new-fangled solid state devices. Luckily sturdier silicon devices were becoming available and JLH was able to design a class-A amplifier that approached the Williamson in its quality and power. This iconic design, initially done for his own entertainment needs, created history with its publication.

Everyman Radio - 1920s

        With each development in technology that happened, JLH stayed at the leading edge and mostly due to circumstance, embarked on certain designs, which later became hot favourites. His adventures trying to replace the mechanical record player at home makes for interesting reading. His lucky discovery of his grandfather's Philco radio of 1938 vintage from the attic, and how that launched him on a redesign/rebuild that was later published in Wireless World, Oct 1986, is another anecdote that reveals the man. Naturally his memoirs are hobbled by the editorial need for brevity of the article, but he succeeds in tracing the milestones of development, including the coming of the MOSFETS, IGBTs, and later the Integrated Circuits, which in a way augured in the modern era as we know it today.

        At all these stages of specialist technical development, we witness JLH dabbling with the tech and coming up with unique and interesting solutions/answers. His designs touched varied fields, from hi-fi audio to top-notch radio tuners, from cassette recorders to precision test instruments. There is not an aspect of electronics that he has not left untouched or unadorned. His grasp of theory and explication are revealed in the countless general articles that he published in the technical Press.

Wireless World April 1947
(Williamson Amplifier)

        For the JLH fan, all that makes for interesting and absorbing reading. I am sure the readers will also enjoy going through the original articles from the Wireless World featuring the 'Williamson Amplifier', that had "stolen the heart" of the young man. Do find the links to the authentic sources below.

JLH: A Lifetime in Electronics:

Part-1: https://drive.google.com/file/d/1C56Ms2slLCncIIiJIirsnfSUUAE32f6D/view?usp=sharing

Part-2: https://drive.google.com/file/d/1pWlPQCQj8joUzL_o_t_PD9byjiacqz5u/view?usp=sharing

Part-3: https://drive.google.com/file/d/1zwFgpdkPcU6wsM65A8C5_r5UgGdhyWjz/view?usp=sharing

Part-4: https://drive.google.com/file/d/1AYZ5lW60KKMWlzslyAtbqlr8vfveCxA8/view?usp=sharing

The Williamson Amplifier- Wireless World, April, May, 1947:

Part-1: https://drive.google.com/file/d/1zKHUXCr7Aiw9l4xo8s1g5cSlTTGhqvCG/view?usp=sharing

Part-2: https://drive.google.com/file/d/11bqyCavZkSJSqUqYdYwuZnk3nGBd1GW7/view?usp=sharing

        In the upcoming posts we shall examine the technical articles of JLH, broadly approaching them chronologically, though there could be groupings like say, audio amplifiers, tuners, test equipment etc. Rather than presenting a dry list of his published articles, I have a feeling that it will be more interesting and useful for the reader if I were to post a summing up/highlights of the various articles presented in each post, and then provide links to the archives of the original articles.

        In the meantime, do read and enjoy, share and comment.

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