I disagree that changing preamps will not give you are wider soundstage.
Definitly try a tube preamp. I had owned Adcom 555 in the past. While they can be a very good sounding piece of equipment, they can be somewhat cold and clinical, especially pairing solid state with more solid state. I made a huge improvement in my soundstage by replacing my solid state preamp with a vintage tube unit. Namely a Dynaco Pas3. I have graduated to Audio Research tube preamps over the years, never going back to solid state preamps.
Good luck,
Mg16
Definitly try a tube preamp. I had owned Adcom 555 in the past. While they can be a very good sounding piece of equipment, they can be somewhat cold and clinical, especially pairing solid state with more solid state. I made a huge improvement in my soundstage by replacing my solid state preamp with a vintage tube unit. Namely a Dynaco Pas3. I have graduated to Audio Research tube preamps over the years, never going back to solid state preamps.
Good luck,
Mg16