API 512V Discrete Microphone/Line Preamp Module for 500 SeriesThe API 512v is a mic line instrument preamp, world famous for its ability to provide a low noise ( 129 EIN) and unusually good sounding front end for all types of audio applications. Sonically, it delivers the instantly recognizable API sound at an affordable price, and in the scalable API 500 Series format. Offering an impressive 65 dB of gain, the 512v includes front panel Variable Output control, switchable 3: 1 output transformer selection,