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 -20dB 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 65dB of gain to an output clip level of +28dBu. 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 +20dBu, making them perfect for keyboards and other high level devices. The mic preamp outputs are on rear panel male XLR connectors.

Features

• Uses API 2520 Op Amps
• Classic API console circuit
• Four female XLR mic inputs
• Four front panel 1/4" Hi Z instrument inputs
• Front panel polarity switches
• Front panel -20dB pad switches
• Front panel mic/instrument switches
• Front panel 48V power switches
• Outputs clip at +28dBu

Specifications

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
  • VU Meter: Calibrated for XLR Outputs, OVU=+4 dBu, (-12, -6, -3, 0, +3, +6, +18)
    Controls: GAIN, PAD (20 dB), 48 Volts, POL (polarity), MIC (mic/un-bal), VU, AC
    Power Consumption, Quiescent: 19.2 Watts
    Size: 19" X 1.75" (1U) X 11" Deep
    Size (Boxed for Shipping): 23.25" X 6.5" X 16.5"
    Actual Weight: 10.38 lbs
    Shipping Weight: 14.06 lbs