The TC Electronic 2240 is a stereo / dual channel mic preamp and 4-band parametric EQ that has both hi-z/mic and line inputs. It's great for tracking keys, or even drums, but it can also be used to EQ pretty much anything in a mix or on the master buss.
Produced by TC Electronic, here is their professional parametric EQ and Pre Amplifier, the model 2240. It is a dual channel mic/instrument preamp, that can also be patched in as a line EQ. What's great about these 4 bands is that they overlap, so you can reach literally any frequency between 20hz and 20khz, and that the Q (or bandwidth) can be set VERY sharp, to allow for very precise corrections in the frequency spectrum. If you really want to go crazy on a track, you could even take the line out of channel A and patch it into channel B's line input to create a single channel 8 band EQ!
The Gear Rack