The D-AOC is an optical tube compressor with a ‘set and forget’ functionality. The original design was done by Analag from the GroupDIY board and was later modified to be more flexible. We did our own version of this nice, transparant compressor with Lundahl input and output transformers and we used only the best Mullard tubes. For mastering you will need total recall, so we made it with stepped switches and also added 3 curve-modes. The original design was done with one vactrol per channel, our version has 4 matched in total for better response. It works great on acoustical music and it adds a nice distinguished tube and transformer sound. We love this beast!