Fulltone OCD V2 The OCD has received many slight tweaks since its birth in 2004, often incorrectly identified as “version 2, Version 3, Version 4.” In reality there has always been only one version…Version 1, with very slight variations in a couple of values after that making them V1.0 through V1.8. All OCDs serial 205811 and higher are the new, less compressed versions some refer to as "v2.01" The OCD was the first pedal to use Mosfets as clipping devices. Another first was their configuration as "hard clippers connected to v-ref" instead of to ground, as was the norm. These things contribute greatly as to why the OCD has such touch-sensitivity...why they react so well when the strings are hit hard or soft, and why they sound & feel different than all other pedals out there, 90% of which are just slight tweaks of the Tube Screamer.