Interference between LEDs (PWM) and DAC (Teensy 3.2)

[darioconcilio]

Hi guys,
I met a problem about interference when I'm using PWM OUTPUT on LED and DAC OUPUT of my Teensy 3.2
This is the sketch that allowed me to understand this behavior.

As you can see from the sketch the audio part has not yet been used, but only set.

If I turn on my led using digitalWrite, audio output is OFF, ok good. Nothing noise.

But I a try ti creare a "behaviour" of my led or only turn on LED with a "middle" light, I hear a noise in OUPUT of DAC's Teensy 3.2.

What can I do to avoid this problem?
Can I decouple the PWM signal from the DAC?

#include <Audio.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <SerialFlash.h>

// GUItool: begin automatically generated code
AudioPlaySerialflashRaw  playFlashRaw2;  //xy=1959,2326
AudioSynthWaveformSine   sine1;          //xy=1961,2401
AudioPlaySerialflashRaw  playFlashRaw1;  //xy=1964,2274
AudioMixer4              mixer1;         //xy=2276,2364
AudioOutputAnalog        dac1;           //xy=2642,2365
AudioConnection          patchCord1(playFlashRaw2, 0, mixer1, 1);
AudioConnection          patchCord2(sine1, 0, mixer1, 3);
AudioConnection          patchCord3(playFlashRaw1, 0, mixer1, 0);
AudioConnection          patchCord4(mixer1, dac1);
// GUItool: end automatically generated code

int color = 0;

void setup() {
  SPI.setSCK(14);
  SPI.setMOSI(11);
  SPI.setMISO(12);

  //analogWriteResolution(7);
  AudioMemory(16);

  mixer1.gain(0, 1);
  mixer1.gain(1, 1);
  mixer1.gain(3, 1);

  sine1.amplitude(0);
  sine1.frequency(880);

  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);

//  analogWrite(3, 120);
//  analogWrite(4, 0);
//  analogWrite(5, 0);
//  analogWrite(6, 0);

  digitalWrite(3, HIGH);
  digitalWrite(4, LOW);
  digitalWrite(5, LOW);
  digitalWrite(6, LOW);
}

void loop() {


//  color++;
//
//  if(color>255) {
//    color = 0;
//  }
//
//  analogWrite(3, color);
//  delay(100);
  
  
}