I'm playing around with different preamps in my new 2-ch system and the imaging or soundstage seems to be different with all of them (given the same source and amplifier). With brand X everything seems to be on a vertical axis centered right b/t the speakers. This is unrealistic to me because the vocalist would need to have a 4ft wide mouth and be laying on their side to produce sound like this. If I had to draw it on paper the imaging would look like the eye of the Cheshire Cat, mostly concentrated vertically. The next preamp dialates the 'cats-eye'pupil a little and becomes a little more realistic, now more circular in nature like coming from a tunnel and then another tube preamp puts it near the floor on a horizontal axis.
I'm not looking for preamp recommendations but I would like to have a better understanding of what causes these changes in imaging. Any recommend reading, links or info would be appreciated.
Christof
