On closeout; He had me at ‘built in bias stabilization’ 
TSAR FACE is a low-gain germanium PNP transistor-based fuzz pedal that embodies the greatest circuit improvement since the original was introduced 60 years ago - a novel two-transistor bias stabilization circuit eliminates the need for transistor gain sorting and reducing temperature issues as well. A buffered TONE control offers up both treble boost and cut, delivering a wide range of tonality. Input impedance is greatly raised allowing TSAR FACE to be used with humbuckers or placed after other pedals. Cleans up nicely with guitar volume rolled down too!
And for all us crossover bass players, be sure to scroll down to the bottom of this page and check out the Valve - 12AU7 Warm Boost Pedal Combined shipping is the same, low, low price! 