The Fulltone 2B is a tiny, transparent, and amazing boost pedal, born from the “Boost” channel in FD3 pedal. Soon after the FD3 came out they started getting a steady flow of emails asking if they could “please make that into a single channel Boost pedal!” So they crammed the circuit into the smallest possible enclosure 4.5" x 2.1" x 2.3" with battery tucked tightly inside and even engineered space-saving rear-mounted IN, OUT, and DC power jacks.
The problem with other boosters is that the more you turn them up, the more highs they add. Not the case with the 2B, there is a subtle roll-off of the harsh ultra-high frequencies as you roll the LEVEL knob clockwise past 12 o’clock. It’s subtle, you may not hear it, but you WON’T hear that shrill top end that other boosters can impart!