Welcome to this tutorial on microphone, record player and guitar pickup level signals.

The audio signals produced by microphones, record players, and guitar pickups all share a common property, they are very quiet and need to be amplified to a line level before they can be processed and mixed. In other respects they differ, and therefore need different devices to convert and amplify them.

Caption - Mic level signals

Mic level signals are produced mainly by microphones. They are very quiet and vulnerable to interference, which is why they are almost always sent in balanced format to a microphone pre-amplifier to be converted to line level.

Demonstration If we connect a microphone directly to the line input of a mixing desk we get an unusable signal.

Caption - Phono (record player) level signals

Phono level signals are produced by record players, and although similar in level to microphone signals, have a radically different equalisation curve and must thus be converted to line level with a phono pre-amplifier.

Caption - Guitar pickup level signals

Guitar pickup level signals are produced primarily by electric guitar and bass pickups. Although similar to microphone signals, they have different impedance needs and must therefore be connected to a suitable amplifier, or a DI box or other device with a DI input, which can convert them to line level.

Caption - Did you know? (non-essential but interesting fact)
Did you know that a microphone produces a very weak signal due to the microscopic to and fro movement of the diaphragm when a sound wave hits it. To produce a louder signal the diaphragm would need to move further, but this would introduce inertia and ‘overshoot’ at the end of each travel, thereby diminishing its ability to track the true pressure changes of the sound wave, and resulting in distortion.

Caption - Thanks for watching

The script for this video, with accompanying images, can be found at projectstudiohandbook.com 

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Thanks for watching.