Mod Bench Special: The is a one-off Vexter Woolly Mammoth with 2N1711 transistors that we obtained from a surplus store. These semiconductors have a darker tonality than what we normally use in this circuit. This pedal is great on a passive bass guitar (such as a P bass) because it doesn't lose the low-end when kicked on, but it's also great on guitar. Also, we added a cool ultraviolet led and different knobs.