API 3124+ Mic/Line Preamplifier #909.3295 (Used)

The API 3124+ Mic/Line Preamplifier is a discrete, high quality, compact, 4-channel mic/line preamp, plus D.I. It is equipped with the RE-115 K mic input transformer and the proprietary API output transformer found in the 512c single mic pre and throughout the API product line. The unit has an internal 48-volt phantom power supply, which is switchable for each channel, as well as -20 dB pad switches that affect both the mic and Hi-Z instrument inputs, both located on the front panel.

Another feature of the 3124+ is that it can provide up to 65 dB of gain to an output clip level of +28 dBu. Additionally, the Hi-Z front panel inputs feed directly to the op amps, which allow a low level input such as a guitar or bass to be amplified without a matching transformer or direct box. These Hi-Z inputs can take input levels as high as +20 dBu, making them perfect for keyboards and other high level devices. The mic preamp outputs are on rear panel male XLR connectors.

TECHNICAL DETAILS:

INPUT IMPEDANCE:

• 1500 ohms Mic, 470 K ohms
• Un-Balanced, HI-Z in Output Impedance: Less than 75 ohms Channel Outputs
• Nominal Levels: XLR Channel Output +4 dBu

STEREO OUTPUT LEVEL:

• Unbalanced: nominal -2
• Balanced: +4
• Clipping level: XLR Channel Output better than +28 dBm
• Frequency response: +0, -5, 10 Hz to 20 kHz (-.5 at 10 Hz)
• Noise EIN: -129 Mic, -125 Un-Bal. Actual
• Measured noise: Better than -91 dBm / below Nominal +4
• Distortion: All Outputs at +4 out, .03%, at +22, .09% Max

GAIN RANGE:

• 150 ohms Input 10 dB min
• 65 dB Max (inc. PAD)
• Un-Bal. Input 14 dB min
• 50 dB Max