Mad about audio
I'm a student electronics engineer in Belgium. I have to make anessay about MADI. I can't find any information about it. Can you give me more information about what it is and how it works?
From Broadcast Engineering's sister publication, BE Radio:
MADI is an abbreviation for Multichannel Audio Digital Interface. It is a standard described by the Audio Engineering Society (AES) standards committee as AES-10 and AES-10id. With it, 56 channels of audio in the form of 28 AES-3 (AES/EBU) format signals can be sent across a single cable. (A single AES-3 channel has two channels by definition.) Its purpose is to provide a more simple means of distributing many channels of audio without the need of multiple cables or paths.
A MADI signal is transmitted via coaxial (AES-10) or fiber optic (AES-10id) cable. These signals are multiplexed — not compressed — so it is a lossless transport mechanism.
MADI is used within facilities to send many audio channels from one point to another. Many routing switcher manufacturers use MADI to connect multiple inputs and outputs to their distribution matrix. Large console manufactures also use MADI to simplify their input configurations. Some facilities use MADI simply as a point-to-point distribution method to reduce the cable requirements.
You can purchase a copy of the formal standard by contacting the company that publishes all the Audio Engineering Society standards, Global Engineering Documents, at 1-303-397-7956, 1-800-854-7179, or online at http://global.ihs.com.
Editor, BE Radio magazine
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Recently a reader asked for help in locating parts for Townsend transmitters. Here's a source: Dave Compton 304-622-9622 or 304-622-9839.
Turn on the lights
I am trying to identify a light control unit associated with one of our towers. Attached is a picture of it. Do you recognize this lighting control? Can you help me locate someone who could supply parts?
The question was passed to our transmission guru, Don Markley. It took him about 20 minutes to locate the answer. The tower lighting unit is a ROHN FA2SS1, built around 1982. Parts are still available from:
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