2-in 2-out USB XRL Audio Interface 48v, open Mic, Preamplifier Streaming Recording

The, open mic, preamplifier, or preamp is an electronic amplifier that converts a weak electrical signal into an output signal resistant to noise and powerful enough to be processed or sent to an electrical amplifier and speakers. Otherwise, the resulting signal will be noisy or distorted. It is often used to amplify signals from analog sensors such as microphones, open mic, and pickups. Therefore, the preamplifiers are usually located close to the sensor to reduce noise and interference.

Suitable preamplifiers are linear (with constant gain over the entire operating range), high input resistance (requires a minimum current to sense the input signal), low output resistance (receiving the output power supply), and minimum variation of the output voltage of open mic. It is used to increase the signal strength so that the cable is routed to the main unit without significantly reducing the signal-to-noise ratio (SNR) of the open mic. The output noise of the preamplifier is very important. If the preamplifier gain is high according to the Fries formula, the SNR of the final signal is determined by the SNR of the input signal and the preamplifier noise from the open mic.

In audio systems, they are used to amplify the analog pickup signal to line level getting from an open mic. The second amplifier is usually an electrical amplifier (power amplifier) directly through an open mic. The preamp increases the voltage (for example, from 10 mV to 1 V), but does not significantly increase the current. The power amplifier provides more power to drive the speakers getting from an open mic. Some common sensors for these systems are a microphone, a transducer, and a phonograph. The preamplifier is usually integrated into the audio inputs of the mixer, DJ mixer, and sound card. They can also be stand-alone devices.