Pretty simple to use, there is 2 sections: preamp and then saturator.
for now, I have tested with a TLM49 and following the order and preamp saturation.
but I would have to look as to use only the saturator. to see!
what I wanted is just to color. the preamp alone is not really colors (and hence I prefer my amek!). against by the TwinTube, adds harmonics where you want (frequency range is selected).
I use it for 3 days. At this price, it's great: just the price of a module 500