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Signal Flow and Amplification - review

Transistor video This video demonstrates what a transistor is and how it uses a very weak signal to control or modulate a very strong one, thereby producing amplification
Signal flow Signals are routed through gear according to a brook - stream - river model. We speak of up-stream and down-stream 
Mixing Consoles  Part 1     Part II     Part III
Basic mixing theory How to record and mix a live band
Stagehand's Audio Guide 2.  Mikes 3.  Stands 4.  Cables 5.  Mixers
  6.  Monitors 7. Intercom 9.  Flow 11.  Cues

Mackie Mixer 

Starting Connecting equipment How to mix PA mixing
  Monitors & submixing In the studio Connectors  


We use a variety of devices to convert energy from one state to another.  These devices are known as transducers.  They are explained here.    
The most common upstream transducer is a microphone.  Microphones are sensitive to shock waves in air.  When they sense a shock wave, they produce a pulse of electrical energy.  The stream of electricity, pulsing in a way that corresponds to the shock waves, is known as the signal flow.  
Do you remember how sound waves are produced and travel?  Want a video review?  Look here  - it's B/W!
Microphone graphics A dynamic mike, a condenser mike, and a ribbon mike.   An electret mike is a widely-used form of the condenser.  Also a loudspeaker (the reverse of a dynamic mike!)
Understanding microphones  Part #1     Part #2     Part #3      Part #4
Microphone techniques A pdf tutorial on how to use microphones
Microphones - Coutant This site will introduce you to the various types of microphones used in broadcasting and in recording studios.  Remember, they're upstream transducers! It is a small sample (only 20 or so), and includes a few of the older models of RCA ribbon microphones such as the 44B and 77DX. Many of these classics still exist, and continue to provide superb audio quality. You can even take a tour of the Neumann factory. Pay particular attention to mike types, frequency response, and polar patterns. This information is provided with each microphone and also, generically, as a link ("Types of Elements") at the very bottom of the first page ("RCA Type 44-BX") of the microphone tour.  Direct links are here.
Microphones for TV Notice here the photo of a parabolic microphone, which actually is a normal dynamic (cardioid) microphone on a parabolic reflector mount.
Phonograph stylus The diamond-tipped "needle" bounces in the record's groove. The needle's connected to a wire coil in the cartridge, placed near a permanent magnet. Each time the needle moves, current flows. The very low output (signal strength) requires an amplifier to be near the tone arm, usually under the turntable base.  This funky video shows an optical "record," too.
Magnetic record head The audio tape is a plastic ribbon many feet in length. Standard reel-to-reel tape speed is 7-1/2 inches per second. The audio recording on the tape exists as many, many little areas of magnetism. As the tape is drawn past the head, each area of magnetism creates electrical flow in the tape head. These signal impulses are sent directly to an amplifier. 
Computer disk drive Uses a tiny, tiny magnetic record/playback head similar to what's in a tape recorder. The disk itself is coated with very fine metallic dust. Because the disk spins, the record/playback head can be made to move along an extremely thin spiral track from the center of the disk to the outermost rim. As the head passes over spots on the track that are magnetized, electrical impulses are created in the head. These are sent to an amplifier in the disk drive.  
Loudspeaker A loudspeaker, or simply speaker, is an electromechanical transducer which converts an electrical signal into sound.  
Microphones Pretty good explanations, with home-made visual aids.

Audio Mixing and Processing Products

Mixing Basic Tutorial
Consoles Explained --   Part #1      Part #2       Part #3
Arrakis .Purveyor of budget-priced automationmixing consoles (air boards), and control room furniture.  Here is the complete catalog.
Enco's DAD Enco's Digital Audio Delivery products are displayed on this page.  You'll find a demo by clicking on the graphic at "DAD."
Signal Processing Dynamic Processing comes under the categories of equalizersfilters, gates and compressors,   
Radio "sound" Heavily compressed, a radio sound is unique.
EAS A description of the system in Alaska is here.
Telephone interface Normally called "a Gentner," the interface controls incoming phone calls and allows you to put them into the audio board.  
Eventide Eventide invented the digital talk show delay for radio.  From this splash page, select "Broadcast" and then "BD600."  The device in use is here, although the video is technically poor.
Abekas AirCleaner The simple machine that puts a profanity delay on audio or both audio and video.   
WavePad This free audio editor is simple and powerful 
Audacity A basic introduction to Audacity.  You'll find many videos on YouTube

LinkedIn > "Learning Audacity" 12) -- 1hr53min; beginner

Adobe Audition How to use Audition for audio effects - Part 1, Part 2 and Part 3

Lynda.com  >  Audition  >  Audition cc 2018 Essential Training  (5hr41min

Misc. (not required)

Radio station Tour a radio station with Corey Deitz
WFPG tour The studios are located at Northfield and Venice Park, NJ and the transmitters are located in the well suited meadows of Atlantic City.  Studio and transmitters. Actually, this site is large and includes much technology of the 1960's and 1970's -- all analog.
Faraday Learn about Faraday, Maxwell, Hertz and Marconi at John Henkins' SparkMuseum.  Good explanations plus clear photos of early radio technology.   On this page you'll find links to key documents related to the emergence of broadcast technology.  Start with Faraday.
Telegraphy Learn about telegraphy, the Morse Code (binary), and the transatlantic cable.


Nikoli Tesla invented alternating current and held many early radio patents.  This site from PBS offers a biography, a profile of five inventions (including "radio"), a tour of his Niagra power station, and an explanation of the fundamentals of electricity.

You can learn about Marconi, read Titanic telegrams, and see footage from Marconi's life here.


From Wikipedia
BBC studios Roger Beckwith's extensive site

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