This will work as a preamp to interface a microphone to guitar pedals.
It looks like the 1/4" output is a 300ohm unbalanced line output, which should interface fine with a high-impedance guitar pedal input. Keep in mind that line level has a higher signal level (i.e. is MUCH louder) than guitar, so you'll want to keep the input & output volume controls quite low.
For reference, a typical guitar signal is ~0.2V peak-to-peak, unbalanced line level is ~1V peak-to-peak, and this line output claims to be able to get up to almost 28V peak-to-peak!