I've been running a Koetsu Black Goldline since last fall. First with a 20+ years old ARC PH3-SE. No lack of soundstage, even then, let me tell you! So its certainly not the cartridge.
Then in December I got the Herron VTPH-2A phono stage. The Herron has got to be one of the all-time great bargains in all of audio. The music that comes out of this thing is really hard to believe, you just have to hear it. My review is here on the site somewhere. Short version, my wife who normally does not notice changes would not shut up about the Herron even though she was only hearing it through the door in another room. Through the door. The closed door.
Never heard the Manley only know it is so well regarded its hard to believe its to blame for your lack of imaging. Since you ask for recommendations though the Herron gets my highest.
Then in December I got the Herron VTPH-2A phono stage. The Herron has got to be one of the all-time great bargains in all of audio. The music that comes out of this thing is really hard to believe, you just have to hear it. My review is here on the site somewhere. Short version, my wife who normally does not notice changes would not shut up about the Herron even though she was only hearing it through the door in another room. Through the door. The closed door.
Never heard the Manley only know it is so well regarded its hard to believe its to blame for your lack of imaging. Since you ask for recommendations though the Herron gets my highest.