from their website:
Q: When the turntable is connected to my computer, I get no sound, either from Audacity or any of my other programs. Why?
A: When you first connect the turntable, Windows XP (and Mac OSX) will often select the "USB Audio Codec" as the audio input and output for your entire system. Since your turntable does not have speakers, audio will not be heard from your programs until you tell Windows not to use the turntable as an output device. Here’s how to change these settings so that your internal sound card will always be used for playback whether or not your TTUSB is connected via USB:
1. For Windows: On the bottom left of your screen, select the "Start" menu.
2. Select "Settings" then "Control Panel".
3. In the window that opens, select the "Sounds and Audio Devices" icon. (If you don’t see a choice called "Sounds and Audio Devices," choose the "Switch to Classic View" option in the panel on the left of the window, and the "Sounds and Audio Devices" icon should become available in the list on the left.
4. Select the "Audio" Tab at the top of the "Sounds and Audio Devices" control panel window.
5. Under "Sound Playback," choose your internal sound card as the default device. This varies by computer but should not be set to "USB Audio Codec" or "Microsoft Sound Mapper".
6. Under "Sound Recording," select "USB Audio Codec" for your default device.
7. Check the box titled "Use only default devices".
8. Click "Apply"...then "OK".
1. For Mac: Open your Hard Disk.
2. Open your "Applications" folder.
3. In the "Applications" folder, open the "Utilities" folder.
4. In the "Utilities" folder, open the "Audio MIDI Setup".
5. In the "Audio MIDI Setup" under Audio Devices, set:
* "Default Input" to "USB Audio Codec"
* "Default Output" to "Built In Audio"
* "System Output" to "Built in Audio"
Now, all programs, including Audacity, will only use your internal sound card for audio output.