I do not use a separate Equalizer. All digital preamp processors have EQ capability of one sort or another. The ones I have used and use currently have EQ in several different forms. The first is your typical parametric EQ but with frequency and Q selection and the second is via Target curves. Parametric EQ can be done on the fly whereas Target curves are designed to address specific problems. As an example some recordings might have a tendency towards sibilance. So I programmed a target curve with a Gundry dip in it. I have a base target curve that tells the system how I want it to sound from an amplitude perspective.
Preamp processors available now are the MiniDSP SHD, The Anthem STR, the DEQX Pre4 and 8, and the Trinnov Amethyst. They range in price from $1500 to $13,000.