Touch Potentiometer Hookup Guide
Joel_E_B 
Example 2: Analog Volume Controller
The next example will show how to use the Analog Potentiometer functionality of the Touch Pot to control both the left and right volume for an audio amplifier. This example will be using the SparkFun Audio Amplifier Kit. The same hookup could be used with the SparkFun Mono Audio Amp Breakout as well.
Hardware Hookup
If you have not done so already, you'll need to build the Audio Amp Kit. Be sure to omit the two PTH Potentiometers included in the kit.
The analog transfer function of the Touch Pot can be set to Logarithmic for a more realistic volume control Non-linear. This can be accomplished in the tputil app mentioned previously.
Next, connect the Analog Potentiometer pins on the Touch Pot to the Audio Amp pins where the PTH potentiometers would have been. There are two channel, each consisting of an A, W and B. We'll consider A as '+', W as Wiper and B as '-'. One the PCB, these inputs map like this:
Here is a look at the underside of the connections.
And from the top...
Once both volume channels are connected, we'll need to provide power to the Amp and the Touch Pot. Since the Touch Pot has a 5V LDO voltage regulator, we can use the same power supply to power both the Amp and the Touch Pot. A supply between the range of 9V-12V should be used to power both. Power routed from the input can be seen in the image below.
Last, you'll need to connect some wires for audio in and audio out. This can be achieved several different ways. The speakers can be attached directly to the amp, or an audio output cable can be attached, as was the case in our example. You can use an audio input cable on the input side. This allows for phones, MP3 players and other 3.5mm jack-type devices to play music through this setup.
With everything connected, apply power. You should see the Amp and the Touch Pot power on. Connect a speaker and an audio source, play some tunes and use the Touch Pot to control the volume!
You can read more about the analog output capabilities in the User Manual.