It's the input impedance of the preamp that matters, not what the outputs can handle.
Electric guitars like to see lots, many guitar pres are around 1 megohm input impedance, or 1 million ohms. Most line gear is around 10kohms, or 10,000 ohms. Anything over 250k should be fine.
Let's put it this way: You won't hurt anything trying it, be careful using the outputs, though, as they will be powered (to drive the headphones) and will distort the input of your recorder easily, and could damage it.