I just bought an Aggie OBP-1 (boost only) pre for my groove tools. All the pots and everything are on what looks to be a cirquit board. My question is, has anyone here ever added a preamp to the CGT7 was it extremely hard? The inside looks REAL complicated, aslo the bass has active Barts. Thanks. If you happen to have a GT7 wiring diagram, could you ples post it?