Feedback
We're all familiar with that awful screeching that comes about from using an amplifier incorrectly. But for many of us, we don't really understand the problem.
This page contains information on what feedback is and some common ways to prevent it.
Feedback, also known as the Larsen effect, is a looping of signal through an input and output, such as an electric guitar and an amplifier.
Electric instruments contain pickups, which are magnetic and act like microphones, by 'picking up' or detecting vibrations in the instrument, such as the strum of a string.
The pickup then converts this vibration into an electric signal, which is sent to the amplifier. Sometimes this signal will create a loop, travelling back and forth between the instrument and amplifier and increasing in intensity. Eventually the amp will overload and produce a painful screeching sound known as feedback.
Now that we understand what's happening in the amp, there are some other things we need to be aware of in order to prevent feedback.
Preventing Feedback
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If volume and or gain are set to high, this can result in feedback. Turn the amplifier's gain and master volume down
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Ensure all cables are properly plugged in to avoid buzzing.
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Ensure your instrument isn't too close to the amp, as this almost certainly results in interference in the signal.
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Using the wrong type of cable can cause feedback. Using speaker cables for instrument connections can result in lots of static and high-pitched squealing.
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Sometimes mobile phones and computers can cause interference through the signals they produce, so ensure they are kept at a distance from the amplifier.
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Tube amps may be affected by fluorescent lighting
If you try all these things and continue to experience issues with feedback or static, it may suggest damage to your cable, amp or instrument,