With the Large Beaver, BYOC set out to give you the most absolutely accurate sonic recreation of an early era Big Muff Pi, but with some added tonal flexibility. Since the component selections used by Electro Harmonix in the early days were very inconsistent, there are many conflicting opinions of what exactly Triangle Era specs and what Ram's Head Era specs should be. So BYOC decided to investigate for temselves. BYOC sampled dozens of vintage Big Muffs and recorded the component values for dozens of specimens. They then compiled the data to determine what the average value (or closest to a standard component value) was for each component. This gives them a far better idea of what the intended component values should be and a tone that is more consistently familiar. The BYOC Large Beaver kit comes with parts to build to Triangle Era specs or Rams Head Era specs including BC239C transistors.

They also added a modification to make the circuit better adapted for any playing situation. Because the Big Muff Pi has such a scooped mid EQ, it can make it hard to cut through in a band setting or impossible to nail your favorite famous recorded muff tones because of post recording EQ. They added a 4 way EQ switch that affects how the tone knob works:

When you take the passive tone stack out of the way, the tone knob bypass offers a huge volume boost with unadulterated vintage muff tone....very cool!