Issues with electret microphone analog output signal

I'm working on a simple project that consists of an Adafruit NeoPixel Ring (https://www.adafruit.com/product/1463) and a Sparkfun Electret Microphone breakout board (https://www.sparkfun.com/products/12758); when the user claps, the ring changes animations. However, I noticed a strange occurrence when I have the microphone and NeoPixel ring connected to the same 3.3V power source on the Arduino. Whenever I wire them like this, the ring works fine but the microphone's analog output signal increases until it reaches its max, even when the room is completely quiet. But when I connect the ring to 5V and the microphone to 3.3V (different power sources), this problem doesn't occur and the project works perfectly. Can anyone explain what is causing this issue?

NeoPixel ring connected to the same 3.3V power source on the Arduino

Let's clarify that - Are you using a 3.3V Arduino or are you using a "regular" 5V Arduino and taking power out of the 3.3V pin?

The 3.3V pin on a 5V Arduino (such as the Uno) can't supply much power. In any case, your 3.3V power supply may not be able to supply the current required by the Neopixel ring. So, the 3.3V may be dropping or it may be very noisy when powering the LEDs.

DVDdoug: Let's clarify that - Are you using a 3.3V Arduino or are you using a "regular" 5V Arduino and taking power out of the 3.3V pin?

The 3.3V pin on a 5V Arduino (such as the Uno) can't supply much power. In any case, your 3.3V power supply may not be able to supply the current required by the Neopixel ring. So, the 3.3V may be dropping or it may be very noisy when powering the LEDs.

I'm using an Arduino Uno and connecting to the 3.3V pin. I tried powering them both using 5V and got the same issue, so I don't think it has to do with insufficient current. Both the ring and microphone are rated for 3-7V I believe.

That Neopixel ring can use almost 1Amp if the ring is driven to full brightness of all the colours. Too much for the 3.3volt pin of an Uno (~150mA). The onboard 5volt regulator or USB also can't supply 1Amp.

I think the main problem is decoupling. There is very little on the microphone board. Run the mic from the cleaner 3.3volt pin. Leo..