1939: Pulse Code Modulation

Jan 1, 2011 9:00 AM

Polls


Mix Regional

The Mix Regional section for Mix's September 2014 issue focuses on Miami. Send us your studio news: updates, sessions, new rooms, plus club performances and installations. Let the Mix audience know what is going on! Send photos and descriptions to mixeditorial@nbmedia.com.

Alec Harley Reeves

Alec Harley Reeves

Discoveries occasionally occur long before the current technology is ready to accept and support them. This is certainly the case with British physicist Alec Harley Reeves, who proposed Pulse Code Modulation (PCM), one of the cornerstone principles of digital audio, more than four decades before the first commercial digital audio recorder.

In his 1939 patent for a Signaling System, Reeves describes a “system for transmitting complex waveforms—for example, speech—wherein the waveform is scanned at the transmitter at predetermined instants” and the “amplitude range of the waveform to be transmitted is divided into a finite number of predetermined amplitude values according to the fidelity required.” He also proposed a tube-based PCM circuit, but this was in 1939—well before the introduction of transistors, ICs or microprocessors—and Reeves’ PCM proposal remained mostly unused until the 1950s, when it was employed in low-fidelity applications such as telephone systems.






Acceptable Use Policy
blog comments powered by Disqus

Mix Books

Modern Recording and Mixing

This 2-DVD set will show you how the best in the music industry set up a studio to make world-class records. Regardless of what gear you are using, the information you'll find here will allow you to take advantage of decades of expert knowledge. Order now $39.95

Mastering Cubase 4

Electronic Musician magazine and Thomson Course Technology PTR have joined forces again to create the second volume in their Personal Studio Series, Mastering Steinberg's Cubase(tm). Edited and produced by the staff of Electronic Musician, this special issue is not only a must-read for users of Cubase(tm) software, but it also delivers essential information for anyone recording/producing music in a personal-studio. Order now $12.95

Newsletters

MixLine

Delivered straight to your inbox every other week, MixLine takes you straight into the studio, with new product announcements, industry news, upcoming events, recent recording/post projects and much more. Click here to read the latest edition; sign up here.

MixLine Live

Delivered straight to your inbox every other week, MixLine Live takes you on the road with today's hottest tours, new sound reinforcement professional products, recent installs, industry news and much more. Click here to read the latest edition; sign up here.

[an error occurred while processing this directive]

The Wire, a virtual press conference offering postings of the latest gear and music news, direct from the source. Visit the The Wire for the latest press postings.