Wherever you want it to be.

I'd only use it in the loop if I were bypassing the amp's preamp, but besides that it depends entirely on the amp, pedals, setup, and your preferences. If it were as easy as one answer they'd print it right on the box.
Preamp boosts would usually be directly in front of the amp to thicken up your tone/improve saturation. A boost in the FX loop will lead to volume boost. c:
Last edited by Will Lane at Mar 5, 2015,
What type of "preamp" pedal? What is this pedal in question?
I'm just a kickin' and a gougin' in the mud and the blood and the beer.
I thought some "preamp pedals" sound like ass in front?
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