API Audio 3124+ 4-Channel Microphone Preamp Demo/Open Box


4 Channel Mic Preamp built around API's legendary detailed and punchy sound.

What we think:

I love using API mic pres because I always know what I’m going to get. Top quality, military grade build and a distinct, aggressive sound that, when the situation calls for it, is nothing short of amazing. This is my top choice when miking a drum kit and want a contemporary sound. It delivers a level of punchy, dynamic tones with an incredible overall forwardness that I just can’t seem to get out of another preamp model. 
The API preamp (3124 and 512c) also performs incredibly well on electric guitars, especially within heavier genres. It’s unparalleled responsiveness and bold overall sound does an excellent job in capturing and showcasing the aggressive playing in metal and hard rock in a very clear and powerful way. I’ve found it to perform at its best when pushing harder on the gain to the point of saturating the fully discrete electronics, resulting in more mid-focused saturation that brings out even more information in the guitar. In these scenarios, I’ll often have to engage the pad to control the signal level and prevent clipping my converter’s input, however it’s a small price to pay to get such an incredible result.
For some projects or instruments, fast and punchy may not be ideal. I almost always want to retain high levels of detail, but would prefer additional smoothness and warmth instead of additional punch. In these cases, I reach for the Phoenix DRS-1R for additional analog saturation to push the material back in the mix just a bit. 
In situations where unparalleled punch, detail, and responsiveness are desired regardless of genre, the API preamp delivers stronger than anything else - Period. For hard rock or metal engineers, it’s pretty safe to say your preamp arsenal isn’t complete without at least 4 channels to cover your drums, guitars, and bass.

Manufacturer Description:


  • 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

The API 3124+ is a high quality, compact, 4-channel mic preamp. 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.

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