Here is a heavy dirty booster that will melt your Orange, Green or Sunn amp head. And your one knob fuzz will love it.😈. The gain range goes from a fairly clean boost to a hairy and fuzzy overdrive. "Transparent" it is not...
It is a fairly simple circuit that boost the whole sound spectrum and relies on op amp clipping. The most common chip used seens to be the olde LM741 which works great for this application. LM308 and CA3130EZ is used as well, the former sounding pretty close to LM741 while the latter is more high gain and has more high end distortion qualities. Note that LM308 and CA3130EZ requires an external compensation cap (read the notes below the layout).
It has two internal trimpots, one for Gain and one for Tone. The Tone trimpot is quite subtle while the Gain trimpot is worth having as an external potentiometer IMHO.
This one is traced by evilarsen, thank you!
More info on the circuit at Blackhawk Amplifiers.
