Is it Safe to Plug an Electric Guitar into a Microphone Input on a Mixing Board or USB Audio Interface?
Is It Safe?
Plugging an electric guitar directly into a microphone input can be surprisingly safe, at least in the sense that no one will be hurt. However, the sound quality and playability will be significantly degraded. The magnetic pickups on an electric guitar do not provide enough current to drive a microphone input effectively, resulting in a poor tonal and dynamic output that is not suitable for live performance or recording.
Proper Channels and Inputs
It is perfectly safe to plug an electric guitar directly into a digital audio interface or USB to computer. For connecting to a mixer, the 1/4-inch tip ring input is the correct choice, not the microphone input. If the mixer you are using has a Hi-Z boost switch, activate this feature to boost the signal from the guitar. If no channel offers a Hi-Z boost option, you can manually adjust the gain and volume. Be mindful of the gain settings, as too high of a gain can result in clipping, noise, or feedback. If you cannot achieve enough volume, consider using a device between the guitar and the mixer input, such as an effects pedal, direct input device, or an active DI box. Some direct input devices even allow for plugging the guitar into a microphone XLR input directly. Adjust the gain to prevent clipping and place the channel fader in the unity zone or slightly above the midpoint for optimal sound level.
Understanding Line Level Inputs
Most mixers have a balanced low impedance input specifically for microphones and a separate line level input for other sources, such as audio interfaces. Even if you can plug a guitar into a line level input, the final sound quality will likely not match the output of a guitar amplifier. The signal from a guitar is at a high impedance, also known as a low output level, similar to that of a mic signal. Therefore, a guitar needs a boost, much like a microphone requires a preamp, to produce a useful and clear sound.
The Author's Experience
The author has several experiences that illustrate the proper way to handle this situation. For example, one technique involves running the guitar through an amp first, then using the amp's headphone out to feed a recording interface. This setup allows for rich and detailed sound, particularly when using reverb and other pedals. Another common approach used by the author involves using a direct box to connect the guitar to a PA system. This method works well for a very dry bass tone in live performances. However, if the mixer lacks a good amp simulation, the sound might be lackluster or undesirable. Some mixers support direct inputs without a Hi-Z switch, which means that if you want a decent guitar sound, using an effects pedal or a direct input device could be necessary.
Conclusion
In summary, it is safe to plug an electric guitar into a microphone input, but the results will be suboptimal in terms of tone and clarity. The best approach is to use the appropriate channels and inputs on your mixer or audio interface, and consider using boost devices or effects pedals to get the best possible sound. Whether you are recording or performing, paying attention to the proper setup will significantly improve the quality of your electric guitar sound.
Keywords: electric guitar, microphone input, audio interface, mixing board, Hi-Z boost