API Audio The Channel Strip - Manual (Page 9)

3.0 Input Section: 512C Microphone/Instrument/Line Preamplifier
3.1 512C Preamp Overview and Feature
The 512C is an all-discrete microphone / instrument /
line preamplifier designed to provide an unusually
good sounding front-end for all types of audio
recording applications. Sonically, it offers the distinct
API sound, high quality performance, and low noise.
The 512C Preamp remains faithful to the circuit
designs of API's founder, Saul Walker. Fully featured,
it carefully preserves the original sound character that
made it so much a part of the early days of recording.
Offering high headroom and a wide variety of inputs and input access points, it is equally at home in the
commercial recording studio as it is in the home project studio.
The 512C Preamp makes use of the
2510 and 2520 op-amps and therefore exhibits the reliability, long life, and uniformity which are
characteristic of all API products.
Features
• Microphone preamp with 68dB of gain
• Line preamp at unity gain
• Instrument preamp with 50dB of gain
• -6dB line pad
• -20dB microphone pad
• Switchable 48V phantom power
• Polarity inverter
• +27dBu preamp output peak indicator
• LED VU meter can monitor preamp output level
• XLR rear panel MIC input
• ¼” -10dBu front panel instrument (INST) input
• ¼” TRS +4dBu rear panel LINE input
• ¼” TRS +4dBu rear panel LINE output
• Low noise (-129dBm EIN)
• Fully discrete API circuit design
• Famous API 2510 and 2520 op-amps
3.2 Preamp Controls
The 512C Preamp provides a comprehensive suite of controls:
• GAIN: Microphone and instrument preamp gain
• POL: Preamp output polarity inverter
• 48V: Phantom Power
• PAD: -20dB microphone pad / -6dB line pad
• INPUT / PEAK: Mic-Line-Instrument input selector and +27dBu output Peak Indicator
• INST: ¼” high-impedance instrument input
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