Why do some amplifiers throw a bigger soundstage than others?

Back in the late ’90s a dealer let me take home a Mesa Baron for the weekend.

I was immediately intrigued and impressed by how up front and close the soundstage was (particularly the vocalist) and how it filled the room to an extent I had never experienced before. At the time I was running a Cary SLA 70 Signature (Cary’s entry level push pull amp) and the reason I did not buy the Mesa and stayed with the Cary (for the time being) was that the soundstage of the Mesa was not nearly as clean and defined as that of the Cary. As a matter of fact, the way I described the soundstage of the Mesa was as being "smoky."

Since then I have owned a couple of other amps (a pair of ARCs and a larger Cary) which provided a larger soundstage, but really nothing quite the same as what the Mesa did, and I have often wondered about that.

I did try to post a link for the Mesa, as I always thought it was a looker, but for some reason A’gon won’t let me do that.

Two reasons:

1. It’s on the recording, and the system is reproducing that recording faithfully because it has the necessary qualities to achieve that.

2. It’s not on the recording, and there are resonances occurring in the system that are causing an effect of reverberation. Examples include feedback from physical vibrations impacting the casework, the electronics, or the mechanical components in the source.

One amplifier be a pitcher. The other be an outfielder?

there are resonances occurring in the system that are causing an effect of reverberation. Examples include feedback

That seems plausible.