XBox 360 Headphone Adapter

360HeadphoneAdapter-OverviewAssembled

When using an XBox 360 with a computer monitor that does not support audio (over either HDMI or using a DVI-to-HDMI cable), there is no easy way to get the audio out of the XBox.

You can use the original 360 Standard A/V cable, but it’s too large to fit on the back of the system when an HDMI cable is also connected.  This is easily remedied by removing the plastic casing from the Microsoft-Branded XBox 360 Standard A/V Cable.  You can then run the RCA plugs for audio into an adapter to convert them to a 1/8″ (3.5mm) headphone jack like RadioShack item number 274-0269.  Then a female-to-female headphone coupler like RadioShack item number 274-1555 will get you the correct gender of connection for connecting your headphones.  One issue, there is no volume control this way.  Add a headphone volume control like RadioShack item number 42-2559, and you are good to go.  This still leaves you with a big bundle of cable behind the system, and a bunch of excess connections (not to mention the exposed wiring from removing the plastic casing from the cable).  I have tested this method, and it works perfectly.  I actually did this as a proof-of-concept.  I knew from prior experimentation that headphone-level signals are usually “close enough” to line-level to be interchangeable and this proved true in this project.

I wanted something slicker that allowed me to connect my headphones (or computer speakers with 1/8″ stereo headphone jack) nearly directly into the XBox 360.  For some reason, NOBODY makes anything that can do this.  So I decided to build my own.

More details, including full build instructions after the break.

The most important component, and star of this project is the A/V cable that we will be using for hacking.  In poking around at what GameStop had to offer, I found the house-brand GameStop/MadCatz NextGen Universal A/V Cable.

360HeadphoneAdapter-GamestopUniversalCable
This puppy can connect your Nintendo 64, Gamecube, PS2, PS3, XBox (original), or XBox 360 to your television in the pure, unadulterated, wonderment of Composite or S-Video.  The GameStop website also indicates that this supports Wii, but the packaging I have does not indicate that fact.  I’m too lazy to Google to see if the Wii uses the same connector as the Gamecube and N64.  I’m also too lazy to try connecting it and finding out myself if it works.

This cable is PERFECT for a number of reasons.  First, none of the connectors or junction points are molded in rubber.  They are a molded plastic casing that is EXCESSIVELY easy to crack open.

360HeadphoneAdapter-UniversalCableJunction
Second, once the cable junction point is opened, you’ll find that there is a tiny circuit board that is LABELED with the connection colors.  Not only that, but the connection colors are exactly what you’d expect when working with audio and video (at least in the scope of our project).  You are only concerned with the Green (Audio Ground/Shield/Common), Red (Right Audio) and White (Left Audio).

After thinking about it for about 3.14 seconds, I came up with a plan.  This was my result:

360HeadphoneAdapter-WiringComplete

I plugged it into my XBox 360, tested everything out and it works very well.  It’s hard to tell in the picture, but what you are actually looking at is this:

360HeadphoneAdapter-WiringDiagram
The shopping list will take you to two stores… GameStop for their cable as shown above, and RadioShack for a 100K Audio Taper Stereo Potentiometer item number 271-1732 and a 1/8″ (3.5mm) Panel Mount Headphone Jack item number 274-0246.  I also grabbed a project box with item number 270-1801 to hold everything.  My total was around $25, and this included both GameStop and RadioShack and the Potentiometer Knobs that I bought (item number 274-0403).

There are differing opinions on wiring this particular potentiometer.  The wiring I used in the diagram above seemed to be the generally-accepted way to do things.  Some people complained about a sharp taper in audio volume over a short portion of the potentiometer’s turning radius.  I’m seeing some of that in this build, but it’s not enought that I’m overly concerned about it.  The volume is probably going to be the type of thing that I rarely change once it’s set anyway.  If you will be using this adapter with a set of computer speakers (or any sort of outside amplification), you could obviously delete the potentiometer from the mix.

Also, the diagram on the package of the headphone jack neglected a few key items.  Namely what audio channel the various connections served.  A quick poke around with my multimeter revealed that the wiring should be as-follows:

360HeadphoneAdapter-HeadphoneJackDiagram
You will see that I’ve modified the RadioShack-provided diagram with a G for ground, L for left (the W is for white), and an R for Right.  The R also stands for Red if you are at all concerned.

Once you have it all assembled and installed into the project box, it will look similar to the following:

360HeadphoneAdapter-InsideBox
The potentiometer is on top, headphone jack on the right, XBox 360 cable exits out the bottom.  I’ve glazed over all of the drilling and notching that you’ll need to do to the project box, but I have faith that you’ll figure that part out.  Here’s what you’ll have once you button it all together:

360HeadphoneAdapter-OverviewAssembled

I have to Dremel the shaft of the Potentiometer before I can install the knob.  Therefore, the pictures on this post do not show the knob attached.

Naturally, there is likely the possibility to expand this project and incorporate a headphone amp (maybe a CMoy?).  This would potentially improve audio quality, and definitely give you more headroom on the volume side.  As it stands in the passive configuration I’ve used for this project, I’m mostly satisfied with the quality and maximum volume.  If I change my mind, I might add an amplifier circuit to the mix.  I have been wanting to build a CMoy amp anyway, and the XBox A/V port provides a +5 volt feed (originally for powering the Optical audio LED).  If I do this, I will need a better connector than the one I used in this project, as the manufacturer deleted any of the contacts that were unused presumably for cost savings.

I don’t know about you, but I’m off to actually USE this guy for a bit.  The PHENOMENAL Need for Speed Shift is calling.

http://www.radioshack.com/product/index.jsp?productId=2102697

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