The Inventions 1981 DRV is a modded Rat, and it's a pretty nice one. If you wanted a more 'hi-fi' Rat, this would be it.
It runs at 18v, which undoubtedly helps with the more open sound/dynamics compared to an original Proco Rat. There's also a slight boost before the main op-amp, where the drive takes place. An op-amp also replaces the simple JFET buffer found on the output of the original Rat.
It's running buffered bypass and should be easy enough to convert to true bypass if that's your preference.
Schematic available at Pedal PCB
INVENTIONS 1981 DRV - VERO LAYOUT
