Microphone signals are typically very low in voltage, around -60 dBV to -40 dBV. Due to their low level, they require amplification through a preamp to be usable in a recording or live sound environment. DI (Direct Input) boxes are often used to convert high-impedance, unbalanced instrument signals (like those from electric guitars or keyboards) to low-impedance, balanced mic-level signals. This conversion allows the signal to be sent over long distances without significant noise or signal degradation.