Q: Can I use the headphone output on the Squier USB Stratocaster without plugging the guitar into USB?
A: No, the headphone output on the Squier USB Strat is only active when the guitar is connected to a Mac or PC or to an iOS device such as an iPad, an iPhone, or an iPod touch. The headphone output allows you to monitor the sound after it has passed through the computer/iOS device, so you can monitor with amp simulation effects. You can also monitor the output from a recording or music app running on your computer or iOS device.