I work for a company that makes products based on Raspberry Pi's. We ship approximately 1,000 Pi's per year. We've been trying to migrate to the new B+ model, but issues with the audio are holding us up. When we try to use the latest firmware, there is audible white noise on the audio output (both on the B and B+.) We've been shipping with old B-only firmware for a long time because of this, and haven't been able to fully migrate to the B+.
One of my coworkers already tried to resolve this issue in this thread:
http://www.raspberrypi.org/forums/viewt ... se#p596302
I would suggest reading the above thread for information on this issue.
It looks like the Raspberry Pi dithers the audio before sending it out the PWM output. Is there a way to disable this dithering, or otherwise disable the white noise?