Bob Moog Inducted into Inventors Hall of Fame

Electronic High-Pass and Low-Pass Filters Employing the Base to Emitter Diode Resistance of Bi-Polar Transistors, Patent No. 3,475,623

It is with great honor that we announce that Bob Moog is one of the United States Patent and Trademark Office 2013 National Inventors Hall of Fame inductees. This is an honor that is bestowed to “individuals who conceived, patented, and advanced so many of the great technological achievements that have changed our world.”

Bob is being recognized for Patent No. 3475623 more commonly known to Moog fans as the Moog Ladder Filter.  Using the new properties provided by transistors, the Ladder Filter was the first voltage controlled filter. By using voltage control such as keyboards and envelopes to steer the harmonic content of music over time, the Ladder Filter allowed new ways of manipulating sound that became part of the basic grammar for a new vocabulary of musical expression.

This humble invention laid the foundation for the electric pulse that beats through all forms of modern music. Bob brought to life basic concepts of dynamic filters used in the mix in every genre of recorded music today.  The Ladder Filter allows the organic movement of sound in such a way that people can not only hear its warmth, but also feel its sweep come to life.  

Patent No. 3475623 is best known for its use in the Minimoog Synthesizer and its effect can be heard on genre defining albums by artists like Michael Jackson, Kraftwerk, Parliament Funkadelic, Emerson Lake and Palmer, Dr. Dre, Diana Ross, and Brian Eno.

Everyone at Moog Music is grateful to be a small part of continuing Bob's work and the enduring legacy of Patent No. 3475623. We would like thank the USPTO for recognizing Bob's great innovation. This year's induction ceremony will take place May 1st in Alexandria, VA at the USPTO headquarters.


Bob's innovation known as Patent No. 3475623 was implemented in a lot of devices and thanks to this amazing voltage controlled filter a lot of great things can be accomplished. My uncle has great knowledge about electrical circuits, his company started using the revolutionary ups systems at at his proposal and everyone were delighted about it`s amazing features, he got very interested about the ladder filter designed by Bob and considers it to be one of the most revolutionary ideas used in Minimoog Synthesizers.
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Great, congratulations to everybody at Moog Music! I just got the new Sub Phatty yesterday; amazing that still nowadays the same filter is state of the art! Great sound, great invention :)
This is thrilling to see. In 1974 I was 19-years old and taking music classes at the University of Utah from Valadimir Ussachevsky who knew Bob. I had a Minimoog Model D and called Moog Music to inquire about pricing for some modular system modules and technical support. But who should answer the phone but Bob Moog himself! I was thrilled! He spent about 15 minutes chatting with me about the best way to go about building my system recommending the Moog filter right off the bat as a great starting point (I was building ADSR's from PIA kits) and he helped inspire me to change my major to engineering as well. What a great guy and I've been a huge fan of his ever since. Congratulations to Moog Music and his family. A great achievement! :)
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