why do expensive amplifiers produce a better soundstage

@ronboco 

You are welcome to come by and judge for yourself.  I am in Orange County, CA.

While a Youtube video can’t convey the soundstage and imaging (much is lost in the recording process and it depends on your own playback system), you can hear the clarity and detail.

The speakers were designed and tweaked in the room for the room over years of listening and there is no eq or room correction, either electronic or physical being used.

https://youtu.be/OmWNOi6b4ak

There is no correlation between amp cost and sound stage. Period. 

@toddalin 

I’m sure your system sounds great and I would love to hear it. If you are ever in Colorado you are most welcome to hear my system too! Happy listening !

From Nelson Pass: "...there is a tendency to interpret negative phase 2nd [harmonic] as giving a deeper soundstage and improved localization [of images] than otherwise. Positive phase seems to put the instruments and vocals closer and a little more in-your-face with enhanced detail."https://www.stereophile.com/content/gramophone-dreams-26-nelson-pass-harmonic-distortion

Second harmonic distortion is something he adds to his amps, which are expensive, so there you are.

Tubes also have it, but "naturally".

Something else about equipment that can detract from soundstage and imaging is poor channel matching, and this can vary with both volume and frequency.

The louder channel will "pull" the image toward that side and you won't get a good center image.