The API 3124V is a high-quality, compact 4-channel microphone preamplifier. The unit has internal 48-volt phantom power switchable for each channel and -20dB pad switches that affect both the microphone inputs and the Hi-Z instrument inputs on the front panel. These Hi-Z inputs can handle levels up to +20dBu, making them perfect for keyboards and other high-impedance instruments. In addition, these Hi-Z front panel inputs are connected directly to the operational amplifiers, so that even low level inputs of a guitar or bass, for example, can be amplified without using a DI box. Input gain and output level can be set separately for each channel. In addition, the ratio of the gain from the 2520 op-amps to the preamps can be selected via a 3:1 option, which changes the sound accordingly;