IMac – Microphone / Headphones combo port does not work in BootCamp

On new Macbook Pros, there is no microphone input. What you have is a line-level input. Microphones that do not have integrated power and amplification (all cheap computer microphones/handsets) will not work when connected to the line-level input.

The connectors are exactly the same, but on the line input there is stereo input and ground, and on the microphone input there is mono input, voltage reference and ground. The input level is also different, with line level at around 1V and microphone level at 10-100mV.

To resolve the problem, you need to get one of the following:

• a USB sound card which has a proper microphone input circuitry,
• a powered, amplified microphone that can be used with line-level input, or
• a microphone preamplifier.

See also:

• http://www.hobby-hour.com/electronics/computer_microphone.php

• http://en.wikipedia.org/wiki/Line_level

Step 1: Download the most recent Cirrus Logic drivers from the Cirrus Logic page. The CS4207 driver is actually more appropriately named "CS42**" driver.

--> go to this page: Here

--> click the "Resources" tab

--> in the "Resources" tab, under the "Tools & Software" heading, select the appropriate driver ZIP file for your particular configuration. Since I am operating in Windows 7 64 bit, I chose the "CS4207 Windows Vista (32/64-bit) and Windows 7 (32/64-bit) Driver, 8/2010, v6.6001.1.26 : 100 KB"

--> download the file to your desktop

--> create a folder on your desktop called CS4207 Drivers (the name doesn't actually matter)

--> move the downloaded ZIP file to this new folder

--> expand the ZIP file within this new folder

Step 2. Go to Control Panel, Device Manager.

Step 3. In Device Manager, open up the "Sound, vide and game controllers" sub menu.

Step 4. If you're like me, you had 4 NVIDIA High Definition Audio entries, and one Cirrus or Intel entry. Click on the Cirrus or Intel entry for the Sound controller. Uninstall the driver and, if it gives you the option to delete the driver files used, do so.

Step 5: Go back to Device Manager, and select "Scan for hardware changes" from the right click dropdown menu.

Step 6. Let your system automatically install whatever driver it wants.

Step 7. Select that new driver entry in Device Manager; right click the entry to update the driver; choose the Browse option, then the Let Me Pick option; and then select the new folder on your desktop as the driver location.