I've been looking at getting some 3.5 mm audio jacks for a project I'm working on and these seem to be the best: http://www.switchcraft.com/productsummary.aspx?Parent=529 The problem I'm having is that I don't know which is better for my application. I'm looking at 35RASMT2BHNTRX which is a dual open jack v.s. 35RASMT4BHNTRX which is a dual closed jack. If I use the dual closed jack can I use those switches to detect that an audio cable is present?
Dual closed v.s. Dual open audio jack
audio
Related Solutions
You don't even need a semiconductor.
In this circuit, when no jack is connected, GPIO will be pulled down to (almost) ground R4. When you insert the jack, R4 becomes disconnected, and R2 weakly pulls GPIO up to AVDD.
In your case you'd have VCC instead of AVDD. And you'd have AUX-ON instead of GPIO.
Rather than futz around trying to change out the existing front panel AC-97 type audio jacks it may make a lot more sense to get a nice drive tray adapter. These are available in an assortment of styles with various features. Here is a basic one that offers the HD Audio (Azailia compatible) (a.k.a. Intel HD Audio) jacks ready to connect into your motherboard.
http://www.newegg.com/product/product.aspx?Item=N82E16813999355
Here are three others to consider with additional features like memory card readers, eSATA connectors, fan speed controls and Firewire.
http://www.newegg.com/Product/Product.aspx?Item=N82E16811996043
http://www.newegg.com/Product/Product.aspx?Item=N82E16820162023
http://www.newegg.com/Product/Product.aspx?Item=N82E16811996006
Best Answer
Unless you need to detect if a connector is plugged in (such as to select or connect something else like an internal speaker/mic instead) the difference is essentially irrelevant.
If you do need to do so, consider which will be most convenient for your circuit. You may find it clearer to look at the schematic symbols on the mechanical drawings than to try to interpet the written description.