You could make up or buy a cable adaptor, but you would need to use high impedance headphones (2K ohms or greater).
Timefactor is designed to feed a high impedance guitar amp, and would probably not give enough level into a low-impedance load – the average iPod-type headphone has an impedance around 30 ohm. But, you could try – it won't damage the TimeFactor.
Or, you could use a commercial headphone amplifier.
