A universal serial bus (USB) headphone amp is a device that produces higher-quality sound and higher volumes by first connecting into a USB port and then connecting headphones into the amp device. Both the quality and sound boost are achieved by pushing more power into the headphones with a power amplifier unit. There are normally settings on the USB headphone amp that allow the user to increase volume or gain, so the sound is matched to the user’s preference. Most USB headphone amp devices can be converted for other applications, such as stereos, by placing batteries in the device rather than plugging it into a USB port.
When someone uses a USB headphone amp, the most obvious change is the volume, because the headphones can reach higher potential volumes when using the amp. The second change, which some users do not notice, is sound quality. Both of these are achieved by pushing more power into the headphones. More power means the volume can be turned up, but it also means there is more power available to reduce static and to stabilize the sound. In effect, a headphone amp is nothing more than a power amplifier that is plugged into a USB port.
Aside from sound quality, USB headphone amp devices rarely affect sound without the user moving a few pieces on the amp device itself. A small wheel commonly allows users to reduce or increase the volume of the headphones. Some higher-end models have other settings, such as changing gain and bass. The headphone amp also may support more than one headphone unit but, commonly, they just support one.
Installing a USB headphone amp takes just a few steps, because the computer does not recognize it as new hardware that needs a driver. The user just has to connect the amp to the USB port and then connect headphones into the headphone jack. This is all that is needed to get the headphone amp working.
A USB headphone amp requires power from a USB port, so this limits its functionality. This means computers and some mobile devices, but not stereos or mobile players that do not have USB technology, will be able to use the headphone amp. To make the USB headphone amp more versatile, most units also can run off battery power. By doing this, the user can connect the unit to a stereo or mobile player and the amp will run off the batteries instead of the USB port.