Pink Noise Flashlight Hack for under $35

We are providing instructions  for a DIY “Pink Noise Flashlight” hack. This is a very easy project and a very useful tool to test and verify microphones.

This device is a battery powered portable pink noise generator that is perfect for testing microphones. For only $35 not only do you get the pink noise generator turn it around and use the LED flashlight function . But don’t stop there as a bonus it is also is a 4000mAh power bank to charge your phone or power small devices in a pinch.

Items needed for assembly

Zealot S1 Bicycling Portable Speaker

Zealot S1 Bicycle Portable Speaker.

Available on Amazon for under $30.

microSDHC Memory Card

A 16GB  Class 10 U1 microSDHC Flash Memory Card. We used a PNY 16GB micro SDHC memory card from Amazon, cost about $5.


  • Testing microphones? Test one two not an option. Use this the pink noise flashlight and verify microphone is functioning properly.
  • Testing Lav and headset microphones. Quickly go through a table of microphones and verify that they all sound the same, give then a little shake and test for noise generated from a bad cable or capsule.

Instructions for assembly

•    Unpackaged Zealot S1 Portable Speaker

•    Plug provided microUSB cable into flashlight and plug into a charger (Charger not included) let charge fully.

•    Download pink noise file from this link.

•    copy pink noise file onto the root directory of microSD card

(You need a SD reader for a computer to do this, the TF card on the speaker is not accessible through the USB cable.

.    Insert microSD card into flashlight microSD slot.

Instructions for  Operation

  • Lift flap to turn on
  • Hold M button (located on speaker side of device) for one second to switch to Music mode
  • Press M button to toggle pink noise on and off
  • hold + button until it beeps to adjust to max volume
  • when finished lift flat and turn off
  • Aditional features
    • USB A port for phone charging
    • LED Flashlight