When you've got some of the best equipment in the world at your fingertips, how do you go one better?Besides the many improvements we have made by modifying some of our gear, we sometimes dream up equipment that doesn't exist off-the-shelf, or at least not to the exact specifications we need or with the features we want.This is when we turn our mind to building exactly what we want. Right now we are part-way through building a custom solid-state mastering EQ. The design provides complete customisation for every band, and the input and output sections can take integrated circuits or discrete opamps allowing virtually endless possibilities.As part of the process, we've been researching and testing many of the best opamps available and will be auditioning them band-by-band and case-by-case. We've also made sure to source electronic components of the highest quality, with extremely tight tolerances between channels.The design goal with this EQ was not to make every band sound tonally or dynamically the same; part of the reason you'll generally see three or more analog EQs in a mastering studio is that each one has strengths and weaknesses in different frequency ranges. For example, the Neve 32087, which we previously owned, sounded great in the lower frequency bands but compromised in the upper mids and higher frequency bands. So when this EQ was chosen for a project, we mostly used it for low boosts and had to use an additional EQ such as the Sontec or Buzz REQ for the higher bands to complete the sonic picture we were looking for.With this custom EQ, we're hoping to eliminate the need for having several EQs by creating the 'ideal' sonic character we're looking for in each frequency band.