Distorted Audio from Speakers and Line-Out I've been working on my early-2008 iMac of late, replacing the HD with and SSD, and upgrading the CPU to 2.8 GhZ. The SSD and new CPU seem to be working fine, except after I finished I ended up with this weird audio problem: ALL audio is distorted. I've shared a couple of links to demonstrate:

Clip of Middle C

Stars and Stripes Forever

This happens both through speakers and audio out. I cannot seem to find the source of the problem. I've tried the following:


Replaced the audio board
Replaced the audio board / logic board flex cable
Replaced the logic board
Booted off an external HD
Downgraded to Mavericks
Reset the PRAM
Reset the SMU
Terminated CoreAudio


NOTHING seems to work. The audio just keeps coming through like it does above. My only thought is maybe my power supply is shorting out and messing with the audio, but I don't want to pony up for a new component until I have a better idea.

Does anyone have any ideas?

Note: This only happens after I boot. The startup chime is not affected.
So I swapped the original CPU back in and everything works fine. Oddly, audio in Ubuntu worked just fine with the original processor, but not in Mac OS X 10.10. Thanks for your help, Tetsujin.