This guide is how to fix the annoying noises (aka distortion) from VoodooHDA.
Step 1: Install VoodooHDA
Go ahead and install the .pkg from Sourceforge here. Once it's installed, reboot your computer.
Mute your speakers prior to rebooting, so you don't damage your speakers in any way..
Step 2: Editing Info.plist
Open Terminal (Applications --> Utilities --> Terminal) and type in the following:
sudo nano /System/Library/Extensions/VoodooHDA.kext/Contents/Info.plist
You'll need to type in your password, then press the Enter key on your keyboard afterwards.
Then, press both Control and "W" once, and type in "iGain" followed by pressing enter.
You will see the following:
Use the arrow keys to maneuver down to "<integer>90</integer>" and change it to "<integer>0</integer>". It should look like the screenshot below.
Once the edit has been made, press Control and "X" once, then press "Y" once, then press the Enter key. Reboot your computer, and the distortion should be gone.
Hopefully my little guide helped you out. If you're still having issues, let me know by replying below.