80dB Noise Preamp

Github: https://github.com/ryanzheng97/noise-amp

A very high gain (80db or x10000) differential AC signal amplifier (LNA, pre-amplifier, noise amplifier, etc.) board based on EEVBlog community design.

Original Post

Board is a 100x100mm 4-layer PCB which falls into the cheap sample tier at JLCPCB or PCBWay.


  • Gain: 80db nominal
  • Bandwidth: <= 1MHz
  • Power: +-18 to 35VDC, unregulated
  • Connector: SMA for signal input and output, 2.54mm THT pads for power input.

Test was done with a 1M to 100R resistor divider in front of the input. Signal was a single-ended sine wave, so one of the input is shorted to ground. Channel 3 shows original signal before resistor divider. Channel 1 shows amplified output.

Noise is about 20mVRMS on the output with input shorted to ground, so about 2uVRMS equivalent input noise.


  • Use high quality electrolytic capacitors
  • Keep away from transformers and other magnetic interference
  • You can replace op-amps with other models that you have or like
  • Avoid ground loop when using
  • Ground one input if using single-ended

Leave a Reply

Your email address will not be published. Required fields are marked *