View Single Post
  #19   Report Post  
Posted to alt.comp.os.windows-10,alt.comp.microsoft.windows,rec.audio.tech
Paul[_21_] Paul[_21_] is offline
external usenet poster
 
Posts: 9
Default Typical first pass tutorial process on Windows 10 where NONEof the extent how to articles actually tell you what you really need to do!

Arlen Holder wrote:


In summary, can you point to the chip you think is that 48-pin ADI chip?
o https://support.hp.com/doc-images/194/c02431965.jpg


I picked that particular chip because it's on *my* motherboard :-)

I would have an incentive to collect the sheet for it. I don't think
I have a very large collection of datasheets. Probably a few AC'97 ones
over the years.

One other thing that's interesting, is some chips have "muxes" for
Stereo_Mix but that one has a "summer", which is an entirely
different kettle of fish.

*******

c02431965.jpg

It took me roughly 3 seconds to spot it. Look for the green
dot in the lower left corner. A little bit down and to the right
a bit from that reference point, you'll find a 48 pin chip. The
chip will be square, and have 4 x 12 pins for a total of 48.
I can't see any detail though - look for a crab icon, the RealTek
icon, because they make a lot of these, all different classes
of audio. Everything from stereo to 7.1 .

HDAudio or AC'97 chips, usually have a pile of small electrolytics
used for AC coupling of signals.

There should also be a separate DC regulator, a linear, that
provides power to the chip. But it's pretty hard to clean
digital noise off a rail using a linear.

Sometimes in the PCB, you can see attempts to build
moats or put guard grounds around some of the analog
wiring. Or stick guards around the Ethernet wires,
so there is less coupling into the analog. There have been
lots of motherboards where total ignorance prevailed near
the 48 pin CODEC chip, and all sorts of mouse noises,
Ethernet noises and so on, ended up in the computer speakers.
It took quite a while for some of the motherboard companies
to become serious about the audio corner of the board.
I mean, in some cases, the interference was so bad, it
was obvious nobody ever lab-tested the audio. Or they
would not have let it ship. Motherboards are designed
three times total, with the third spin required
to be "patch wire free". Plenty of time to do an audio
test.

Paul