[volanin]

I've been searching around the net and reading the kernel docs, and I THINK I found a solution.
I have powered-up the computer only a few times since I did this, but the sound was loud,
very clear and with not crackling at all. So I am posting it here for you to try as well.

Follow these steps:


1. Open a terminal.

2. Type:

$ sudo gedit /etc/modprobe.d/options

3. Add the following line to the end of the file:

options snd-hda-intel model=[MODEL_BELOW] position_fix=2 probe_mask=1

4. Save the file and type in the terminal:

$ sudo update-initramfs -u

5. Reboot your computer.


You must select the Intel HDA model that corresponds to your computer:

intel-mac-v1   : Intel Mac Type 1
intel-mac-v2   : Intel Mac Type 2
intel-mac-v3   : Intel Mac Type 3
intel-mac-v4   : Intel Mac Type 4
intel-mac-v5   : Intel Mac Type 5
macmini        : Intel Mac Mini (equivalent with type 3)
macbook        : Intel Mac Book (eq. type 5)
macbook-pro-v1 : Intel Mac Book Pro 1st generation (eq. type 3)
macbook-pro    : Intel Mac Book Pro 2nd generation (eq. type 3)
imac-intel     : Intel iMac (eq. type 2)
imac-intel-20  : Intel iMac (newer version) (eq. type 3)

For example, I have a Macbook 3rd generation, and the only setting that worked was
model=intel-mac-v3. All others just gave me NO sound at all, including the apparently
obvious macbook and the documented-as-equivalent macmini ones.

If nothing works, you can revert this by deleting the line and performing the rest of the steps.


For BEST sound, if the above works, open a terminal and type:

$ alsamixer

And set the FRONT and SURROUND sliders to their maximum.
It might be necessary to unmute them with the 'M' key.
Press ESC twice to leave the program.



EDIT:
It was confirmed by cipher999 that position_fix=1 works as well.
Thanks!