Here’s some details in Catalinbread’s own words:

You've discovered the Catalinbread Super Chili Picoso, a bad assed clean boost pedal based on the Guru Jack Orman's topology. It like many of its predecessors utilizes the BS170 MOSFET to boost your signal with a very natural tube like response.

The Super Chili Picoso is the clean boost pedal folks guage others by. With about 35dB boost, it can however drive the input of a nice tube amp into the type of overdrive that guitar players have desired for years. I probably will never go back to the Screamer for a "natural" dynamic overdrive tone.

When used as a clean boost (that is not pushing your amp into overdrive) it will make "thin" sounding pickups sound more ballsy and full because it does not limit frequencies as basic treble boosters do. The Super Chili Picoso is for any guitar player who loves the tone of their tube amps (who the heck doesn't?) but has always wanted "MORE" out of them. The Picoso delivers this with ease and then some.

Many Picoso uses have told me that they NEVER turn this pedal off! They have informed me of a number of uses for their Super Chili Picoso. First, as a clean pure decibel boost for solos and loud passages setting the gain to about 75%. Second, as an overdrive unit that pushes their amp into overdrive utilizing their tube amp's natural overdrive setting the gain to above 80%. Third, as a buffer/line driver for driving long cable runs or pedal chains setting the gain to unity (the Picoso does not attenuate levels). Next, as a signal to amp kill switch for silent on-stage tuning. Finally, both outputs can be used to bridge channels on two channel amps w/reverb correcting the internal phase cancellation that arises from this practice. This is a fun trick for all of you Super Reverb players who want to bridge chanels like Bassman nerds do.