i recently had my amp tech install the "hoffman" AB763 board to replace the guts of my DRRI. while i'm not sure it made the amp sound better (i also had him replace all four transformers with mercury magnetics iron), it certainly is "cooler" and will be easier to repair/mod in the future. one thing that definitely DOES sound better is the vibrato circuit, which is much more lush and warm-sounding. the build quality is excellent, with mil-spec soldering that dave reeves would approve of.

Rating: [5 of 5 Stars!]