The Cesar Diaz Texas Square face was originally designed as a replacement for Stevie Ray Vaughan's fuzz faces, which were always dying. C?sar built his circuit into one of SRVs dead fuzz face boxes and Stevie used it until his unfortunate death. The square face is similar to the Dallas Arbiter Fuzzface, has Volume and Fuzz knobs, but comes in a small MXR distortion+ sized box. Here is some info from C?sar: The square face is NPN not PNP..it comes with two germaniums but it has transistor sockets and two silicon's are included for more gain. They can also be combined, for different tones. Changing positions will also help!! You can really hear it on the SRV album "IN STEP"...cesar... All units are now powder coated instead of painted, which is stronger and looks better. Also the inside is coated so it will not corrode. This pedal has "Absolute Bypass." All Diaz Musical Products effect pedals are individually hand-constructed, wired, tested.