Often hailed as one of the most iconic overdrives that once was the "grey spec" 250 offered a warmer and smoother,  if you will, drive tone than the modern reproductions. Something I found out when breadboarding this circuit is that with a few subtle mods the shortcomings of this circuit could be corrected. One of the issues is that when the gain reaches a certain threshold the pedal seemed to get a bit lets just say "annoying" on the high frequency side of things that people often refer to as that "box of bees" kind of sound. The solution was to modify the high end portion of the circuit to retain a little more warmth and to level out that frequency. Another shortcoming was at higher gain the low end seemed to just disappear although, this was just with the stock clipping diodes in the circuit. The solution was to modify the low end frequency range and install a switch to modify the low end to retain that fullness. Another improvement is to modify the clipping portion of the circuit swapping out the stock diodes for LEDs and then providing a center off position which removes the diode portion of the circuit. This provides more headroom and a much louder and low end heavy sound to the circuit. So with those few adjustments I've found this little box has quickly become one of my favorite overdriven tones out there. The OD/Pre-Amp is powered by a 9vdc 2.1mm center negative power supply. The pedal is true bypass and handmade by me right here in Guilford, Indiana,.Like all of our pedals it comes with the standard one-year warranty on 
parts and labor. If you should happen to have any questions about this pedal or any other Wilson Effects pedal please feel free to contact me through the contact form on the Home page of the site.